Subject: RE: [teres] Teres: Subchassis & Armboard Date: Tue, 15 Feb 2000 15:23:56 -0700 From: David Dlugos, David Dlugos To: teres@aiko.com > I think we may be able to improve beyond wonderboard. Im not sure >it is as >dense as it could be it may have an expander in it. We might be able to mix >up a concrete product that is denser and would pour into a void or base. >There are a lot of concrete modifiers now days we might be able to produce a >wet mix that is denser than wonderboard and fits perfectly inside a base, >some of the acrylic modifiers even move it towards an elastic material that >might damp better. There are cement /acrylic materials for setting tile >that might fit this description. I have been lurking till now, but i thot it might be time to throw in my 2-bits worth here. First, what is a TT supposed to accomplish: a TT system's job is to hold the body of the cartridge such that there is no relative motion between it and the record it is playing. If this can be done then the relative movement of the stylus wrt the cartridge body that generates the electrical signal is an analog of the grooves on the record. So how does this affect how the base/armboard is built. This critical assembly has to ridgidly couple the arm to the record (thru the bearing), it should not ring, and it should not store energy that will later be released into the system and cause a time smear. These goals tend to tug at each other, so any solution will be a compromise. One needs to walk a fine line. dave __________________ Transmission Line Speaker Page http://www.t-linespeakers.org/ Subject: Re: Teres-Subchassis/Armboard Date: Mon, 7 Feb 2000 00:08:37 -0700 From: Thom Mackris / Joan Panzella, Thom Mackris / Joan Panzella To: Tony Bombera; Tim Bailey; Thomas Martin(w); Thomas Martin (h); Thom Mackris (w); Terry Gesualdo; Stewart Ono; Steve Zettel; Steve Brooks; Stan Goudge; Sammy Pao; Roscoe Primrose; Ron Welborne; Peter Clark; Peter Boser; Mitaru, Alex; Ken Schei (w); Ken Schei (h); Jon Lane; Joe Druley; Jeremy Epstein (w); Ivan Anderson; Igor Kuznetsoff; Grant Sellek; Grant Gassman (h); Gon, Martin; George Munger (w); Gary Bronner; Fred Humphrey; Don Carron; David Suess; Dave Collier (w); Chris Brady; Brian Day (h); Brian Boehler; Bob Pickwoad(h); Bill Mollard; Beck, Chris; Allen Wright; Gordon Maughan I think Tim meant to post this information to the list. He probably thought that doing a reply would send it to majordomo, but due to you slackers out there (you know who you are), I'm still using my private, kludgy e-mail list and when he replied to sender, I was the only recipient (hint ... hint ... sign up already !!). Anyhow, here are two e-mails from Tim. The first one you read was sent after the fact as clarification for the latter (longer) one. Cheers, Thom ----- Original Message ----- From: To: Thom Mackris / Joan Panzella Sent: Sunday, February 06, 2000 10:28 PM Subject: Re: Teres-Subchassis/Armboard - Digest 12/16/00-2/6/00 Background to previous post. I have tuned a lot of sprung TT's like Thorens Ara nd Linn,and have worked pretty hard at isolating my Thorens TD 150. I ahve avery hevay cast cream concrete step mounted on angle brackets to the exterior timber wall (real brick veneer house!). I hav tried compliances under it but have come back to none ata ll and making it as rigid as poss. ----- Original Message ----- From: To: Thom Mackris / Joan Panzella Sent: Sunday, February 06, 2000 10:25 PM Subject: Re: Teres-Subchassis/Armboard - Digest 12/16/00-2/6/00 I think the thing to remember is that it might depend on the room where you are situating it, eg size, layout of gear, structure, and where a truly stable mounting point exists. With a compliantly suspended (or hung) mass we need to be careful about its mass. If a very low frequency motion is passed into a large mass, bypassing or through the compliance, it may start oscillating, just because it is free to. Here the mass makes it less stable, because it is suspended???? You need a combination of 'rigidly mounted' (?) mass/es to resist motion through inertia, and then vibration absorption within a rigid container like a sand box, and then use a suspension. Further improvement comes with an 'independent' cover or 'box', as discusssed with Thom Mackris. The 'box' is arranged so as never to contact the TT or its suspension/s isolators, but might sit on the inertial mass. Double-glazing the clear lid and sand filling the sides would increase effectiveness. While I do not favour vacuum clamping of LP's, a partial vacuum is a poor transmitter of sound. So, use a vacuum pump to evacuate the 'box'! Yes, air-borne and structure borne AF waves striking the inertial mass underneath the box would continue to be filtered and by the suspension and vibration isolation systems inside it. These elements now have less to do, and so will be more effective. (The vacuum pump might need to be sited out of hearing.) (Acknowledgements due to Bill Pearl). Tim B Subject: Re: Teres: Subchassis & Armboard Date: Mon, 7 Feb 2000 00:26:47 -0700 From: phclark, phclark To: Thom Mackris / Joan Panzella; Allen Wright; Beck, Chris; Bill Mollard; Brian Boehler; Brian Day (h); Chris Brady; Dave Collier (w); Don Carron; George Munger (w); Grant Gassman (h); Grant Sellek; Igor Kuznetsoff; Jeremy Epstein (w); Joe Druley; Jon Lane; Ken Schei (h); Ken Schei (w); Mitaru, Alex; Peter Boser; Ron Welborne; Steve Zettel; Stewart Ono; Terry Gesualdo; Thom Mackris (w); Thomas Martin (h); Thomas Martin(w) I was reading through the digest on armboards, etc. and was a little troubled by the whole notion of suspension. Goes to show about received wisdom, I guess. I have been told repeatedly that a suspension's principal worth is on "resilient" floors, e.g. wooden or composition floors on joists. In my neck of the woods, this is an uncommon method of construction, mostly what you see is concrete slab over ABC on grade, which is pretty inert, unless you're near a railroad switching yard. In my case I have either slab (ground floor) or 12" prestressed concrete floors (second floor and roof) (my house is built like a bank vault.) The "wisdom" here maintains that it is more desirable to couple the 'table assembly to the floor than to introduce potentially destabilizing springs, neoprene bushings and the like. This is a view I tend to subscribe to. I presently use two 'tables, one with suspension and one without one of any sort. On the one without suspension, tweakage has been achieved with mats to my general satisfaction within the limits of the 'table. The one with suspension has never performed to my expectation, even after spring changes, etc., etc. and for some reason isn't amenable to mat changes either (the principal reason I want to do a "proper" 'table.) So, having said all that, I solicit comment. Bear in mind I was the one who suggested the notion of a *heavy* machinist's surface plate as a foundation. My conceptual intent was to do a foundation with separate stone spiked subchassis for motor, platter and arm, relying on the total mass to kill unwanted nasties. If that concept has validity on solid floors, I'd appreciate some corroboration or someone telling me I'm all wet, and also why. I'm here to learn. Thanks. Peter C Subject: RE: Teres: Subchassis & Armboard Date: Mon, 7 Feb 2000 11:01:36 -0700 From: Mackris, Thom G., Mackris, Thom G. To: Anderson, Ivan; Bailey, Tim; Beck, Chris; Boehler, Brian; Bombera, Tony; Boser, Peter; Brady, Chris; Bronner, Gary; Carron, Don; Clark, Peter; Collier (w), Dave; Day (h), Brian; Druley, Joe; Epstein (w), Jeremy; Gassman (h), Grant; Gesualdo, Terry; Gon, Martin; Goudge, Stan; Huber, Manfred; Humphrey, Fred; Kuznetsoff, Igor; Lane, Jon; Mackris (h), Thom; Martin (w), Thomas; Martin(h), Thomas; Maughan, Gordon; Mitaru, Alex; Mollard, William; Munger (w), George; Ono, Stewart; Pao, Sammy; Pickwoad (h), Bob; Primrose, Roscoe; Schei (h), Ken; Schei (w), Ken; Sellek, Grant; Suess, David; Welborne, Ron; Wright, Allen; Zettell, Steve Peter, You raise some good points, as well as alluding to how construction differs in various parts of the country/world. In places where basements are prevalent (East Coast, Denver area where I live), suspended floors are the norm. In the Phoenix, AZ area, first floors were slab concrete. Most definitely we will be seeing several optimal siting solutions for our 'tables with one major variable being household construction. I would guess that with respect to suspensions, a poorly designed/set up suspension would be worse than having none. This is not to cast aspersions on your set up skills, but meant to be more of a general statement. A recent air support experiment with my Merrill produced wildly varying results depending on the air pressure. My setup made varying the pressure difficult as I didn't take the time to rig up an extension valve for the tube. Each iteration (pressure change) required one person to hold the table while the other added/removed air. Re-leveling was necessary after each adjustment. We ran out of patience after four iterations and never got to the quality level that I attained with my Archi-Dee stand (light & rigid, in the Linn school). I am optimistic that an air suspension can sound good with my Merrill (again, I have a sprung floor, etc. etc.) but an easily adjustible tube (valve extender, etc.) is absolutely necessary in order to experiment with the setup. Parenthetically, my Merrill sounds totally dead when I site it on a massive stand. I'm not talking about resonance and false excitement being reduced, etc. When I placed it on a massive stand (I built one out of MDF, 175 lbs of sand) that greatly improved the Sota I had previously owned, dynamic range on the Merrill droped away and everything else got worse. This is obviously a pass-band tuning problem, as I'm sure that the Merrill springs can't filter out the low frequencies that a massive stand passes to them where the Sota was designed to do this. Our tables will certainly be different from my Merrill and irrespective of whether or not we suspend them, I'm 100% certain that they will prefer mass beneath them the way my Sota did. I will most certainly try a non-suspended arrangement, and most likely I will try this first, as it will serve as a baseline. I know that engineering is the fine art of compromise and I may get back more than I give up in this configuation. I expect a lot activity on this list once we get to the area of setup. Cheers, Thom -----Original Message----- From: phclark [mailto:phclark@uswest.net] Sent: Sunday, February 06, 2000 11:27 PM Subject: Re: Teres: Subchassis & Armboard I was reading through the digest on armboards, etc. and was a little troubled by the whole notion of suspension. Goes to show about received wisdom, I guess. I have been told repeatedly that a suspension's principal worth is on "resilient" floors, e.g. wooden or composition floors on joists. In my neck of the woods, this is an uncommon method of construction, mostly what you see is concrete slab over ABC on grade, which is pretty inert, unless you're near a railroad switching yard. In my case I have either slab (ground floor) or 12" prestressed concrete floors (second floor and roof) (my house is built like a bank vault.) The "wisdom" here maintains that it is more desirable to couple the 'table assembly to the floor than to introduce potentially destabilizing springs, neoprene bushings and the like. This is a view I tend to subscribe to. I presently use two 'tables, one with suspension and one without one of any sort. On the one without suspension, tweakage has been achieved with mats to my general satisfaction within the limits of the 'table. The one with suspension has never performed to my expectation, even after spring changes, etc., etc. and for some reason isn't amenable to mat changes either (the principal reason I want to do a "proper" 'table.) So, having said all that, I solicit comment. Bear in mind I was the one who suggested the notion of a *heavy* machinist's surface plate as a foundation. My conceptual intent was to do a foundation with separate stone spiked subchassis for motor, platter and arm, relying on the total mass to kill unwanted nasties. If that concept has validity on solid floors, I'd appreciate some corroboration or someone telling me I'm all wet, and also why. I'm here to learn. Thanks. Peter C Subject: My two cents after reading the attached digests Date: Fri, 11 Feb 2000 03:09:44 -0700 From: Micheal Larosa, Micheal Larosa To: tmackris@earthlink.net After reading through the digests I have a few questions and comments. questions: What size is the thread on the outside of the brass bearing? Will the spindle tips (threaded for clamp and non threaded versions) have flats machined on them to facilitate ease of insertion and removal? Any idea on the diameter of the pulley and idlers? comments: I worked in a plastics shop for three years. during wich i did most of the acrylic work there. Concerning cutting and forming:Cutting is best performed with a table saw and a carbide tipped blade with a two to three deg. negative rake.Care must be taken to feed the saw at the appropriate rate,otherwise binding,melting,or chipping may result.(binding is definitely a problem as 1" acrylic is extremely thick and is not recommended for beginners!)It's also very heavy. I.E. two people are a must when putting a 4'x8' sheet on the table saw! Forming can be done with a typical router and carbide bits used for woodworking, again assuming the proper feed rate so as not to chip or melt the plastic. Half inch shank bits are recommended as acrylic is remarkably tough stuff. Concerning "gluing" acrylic, the primary solvent used is metheleyne chloride, along with some other ingredients to speed up or slow down the setting process, and rid the process of bubbles. This "glue" is the consistency of water and if used properly needs no vacuum process to give excellent bubble free results. IMHO,the group may want to consider, (if they haven't already done so)having a plastics shop in the vicinity of the machinist's location rough cut and laminate the acrylic sheet.Unless of course the machinist is experienced in these things. The "gluing" process is a bit tricky, and poor results are easily achieved.(I speak from experience here.) ;-) Hope this sheds some light on the situation. The acrylic plinths being considered by some in the group can be easily achieved by cutting and shaping a pattern of wood. Use double sided masking tape attach the acrylic to the pattern. Trim closely to within 1/4" of the pattern. and then rout with a flush cut bit on your router table! I welcome any questions and comments ( jolly, rude or otherwise)concerning my sermon here. I would like to offer my greatest thanks for the opportunity to be a benificiary of this great collection of insights and ideas. Michael LaRosa Subject: [teres] Inner Tubes and concrete floors Date: Fri, 11 Feb 2000 07:27:00 -0700 From: Sellek, Grant (TSA), Sellek, Grant (TSA) To: 'Teres List' Is there any value from using an inner tube suspension with a solid concrete raft floor, such as at my home? Or am I just as well off to connect everything solidly to the floor? Grant -----Original Message----- From: Igor Kuznetsoff [mailto:gorkuz@yahoo.com] ..... I certainly agree with you about the air suspension. I've crusading for the use of small bicycle (2.25 or 2.45 x 12") inner tubes, Subject: Re: [teres] Inner Tubes and concrete floors Date: Fri, 11 Feb 2000 11:35:47 -0700 From: phclark, phclark To: teres@aiko.com FWIW, my guess is no to a suspension on a concrete floor. A suspension adds complexity and potential tuning difficulty in a situation where it may not be required. My plan is to employ a machinist's surface plate as a plinth with separate boards (acrylic or granite) on spikes (felt has been suggested) for the motor, platter and arm. If this approach doesn't work, since I already have the base for the surface plate, I'll construct a sand box to place the surface plate into. Failing that, another surface (MDF/more granite) on the surface plate base to put inner tubes upon, thence the sand box, thence the surface plate. Plan "C" is pretty damn complex compared to Plan "A," but is a logical progression. My take on suspensions is, assuming that the bearing/motor lashup doesn't contribute its own vibration (in which case you haven't done your homework) what you are attempting to do is isolate the platter/arm from the environment. If your floor is stable (barring 18 wheelers or railroad switchyards) your work might well be done. Of course, I could be all wet. Regards, Peter C "Sellek, Grant (TSA)" wrote: > > Is there any value from using an inner tube suspension with a solid concrete > raft floor, such as at my home? Or am I just as well off to connect > everything solidly to the floor? > > Grant > > -----Original Message----- > From: Igor Kuznetsoff [mailto:gorkuz@yahoo.com] > ..... I certainly agree with you about the > air suspension. I've crusading for the use of small > bicycle (2.25 or 2.45 x 12") inner tubes, Subject: [teres] Re: My two cents after reading the attached digests Date: Sat, 12 Feb 2000 01:09:40 -0700 From: Thom Mackris / Joan Panzella, Thom Mackris / Joan Panzella To: Teres_List; Micheal Larosa Hi Michael, We are transitioning over to the list server, so I'm replying to you and copying the "list". Check Chris' website for signup instructions to the list: http://reality.sgi.com/cbrady_denver/audio/ I truly appreciate your comments and Chris Brady will most certainly be reading them. While I don't have time for detailed comments at the moment, let me at least begin the process. The acrylic will be cut by a plastics shop near our machinist (Bryce), in Newberg, OR. I'm certain that this is under control. The bonding process you mention may indeed be overkill on Bryce's part and not necessary at all. I'm certain that Chris will forward this to Bryce for commentary. Bryce is apparently as "nuts" as we are (thankfully) and perhaps is being way overcautious. The threaded portion of the brass bearing is (IIRC) 1-1/8" and a nut will be supplied. Bryce will machine the nut down to 1/2" height. By "flats" do you mean chamfers on the end of the spindle which threads into the bearing? I believe they will be chamfered. Or ... are you talking about the business end that the LP passes over? The non-threaded one will most definitely have a taper to facilitate the LP slipping over it. I believe the threaded one will just end with a clean thread, much the way my Merrill does and Steve Z's Oracle. Remember that this is a .25" thread, and the record spindle portion below it is .280", so the threaded portion passes easily (on my Merrill) through the LP hole. I'm tired, and I hope this is clear, but if not, we will continue :-)) Let's pick the remaining questions up tomorrow. Cheers, Thom ----- Original Message ----- From: Micheal Larosa To: Sent: Friday, February 11, 2000 3:22 AM Subject: My two cents after reading the attached digests After reading through the digests I have a few questions and comments. questions: What size is the thread on the outside of the brass bearing? Will the spindle tips (threaded for clamp and non threaded versions) have flats machined on them to facilitate ease of insertion and removal? Any idea on the diameter of the pulley and idlers? comments: I worked in a plastics shop for three years. during wich i did most of the acrylic work there. Concerning cutting and forming:Cutting is best performed with a table saw and a carbide tipped blade with a two to three deg. negative rake.Care must be taken to feed the saw at the appropriate rate,otherwise binding,melting,or chipping may result.(binding is definitely a problem as 1" acrylic is extremely thick and is not recommended for beginners!)It's also very heavy. I.E. two people are a must when putting a 4'x8' sheet on the table saw! Forming can be done with a typical router and carbide bits used for woodworking, again assuming the proper feed rate so as not to chip or melt the plastic. Half inch shank bits are recommended as acrylic is remarkably tough stuff. Concerning "gluing" acrylic, the primary solvent used is metheleyne chloride, along with some other ingredients to speed up or slow down the setting process, and rid the process of bubbles. This "glue" is the consistency of water and if used properly needs no vacuum process to give excellent bubble free results. IMHO,the group may want to consider, (if they haven't already done so)having a plastics shop in the vicinity of the machinist's location rough cut and laminate the acrylic sheet.Unless of course the machinist is experienced in these things. The "gluing" process is a bit tricky, and poor results are easily achieved.(I speak from experience here.) ;-) Hope this sheds some light on the situation. The acrylic plinths being considered by some in the group can be easily achieved by cutting and shaping a pattern of wood. Use double sided masking tape attach the acrylic to the pattern. Trim closely to within 1/4" of the pattern. and then rout with a flush cut bit on your router table! I welcome any questions and comments ( jolly, rude or otherwise)concerning my sermon here. I would like to offer my greatest thanks for the opportunity to be a benificiary of this great collection of insights and ideas. Michael LaRosa Subject: Re: [teres] Re: My two cents after reading the attached digests Date: Sat, 12 Feb 2000 20:55:45 -0700 From: Thom Mackris / Joan Panzella, Thom Mackris / Joan Panzella To: Stewart Ono; Micheal Larosa; teres@aiko.com Hi Michael, I think I addressed all but one item from your earlier e-mail. Note that I'm copying you and Stu Ono in addition to the list, as I believe that both of you have still not been successful in subscribing. Direct any questions or problems you might have to Roscoe at his "administrator's" address: owner-teres@aiko.com The only unanswered question has to do with the pulleys. The motor pulley will be addressed as part of the motor design, and it is highly probable that Bryce will be machining them. The original thinking was to make them of acrylic in order to maintain the same thermal expansion (relative speed accuracy) rate as the platter. With Manfred's design however, this may no longer be an issue. We will certainly kick this design around in the coming weeks. The whole issue of whether to incorporate idler pulley(s) into the design is also open at the moment, and will certainly play a part in the motor and subchassis dialogs. I think folks will split into a two camps: (a) one group favoring idlers and (b) the KISS group which won't. Fortunately, this part of the project is totally flexible. My concern about doing idler pulleys is that I think they must be done impeccably or not at all. I may just wait and stand on the shoulders of someone else's ambitious efforts before tackling it myself. It seems as if the safe bet is to machine the pulleys for later use even if one chooses to not explore this approach initially. Sourcing bearings for the pulleys will certainly be a challenge. Johannes Chiu (http://www.columbia.edu/~jsc19/turntable.html) used VCR heads as idler pulleys (in contact with the platter !!) to add rotational inertia to the platter without adding weight. These heads are apparently quite high quality as far as their bearings are concerned. Johannes has some interesting ideas, and it would be interesting to return to them two months after directing the list to his website. Cheers, Thom ----- Original Message ----- From: Micheal Larosa To: Sent: Friday, February 11, 2000 3:22 AM Subject: My two cents after reading the attached digests After reading through the digests I have a few questions and comments. questions: What size is the thread on the outside of the brass bearing? Will the spindle tips (threaded for clamp and non threaded versions) have flats machined on them to facilitate ease of insertion and removal? Any idea on the diameter of the pulley and idlers? comments: I worked in a plastics shop for three years. during wich i did most of the acrylic work there. Concerning cutting and forming:Cutting is best performed with a table saw and a carbide tipped blade with a two to three deg. negative rake.Care must be taken to feed the saw at the appropriate rate,otherwise binding,melting,or chipping may result.(binding is definitely a problem as 1" acrylic is extremely thick and is not recommended for beginners!)It's also very heavy. I.E. two people are a must when putting a 4'x8' sheet on the table saw! Forming can be done with a typical router and carbide bits used for woodworking, again assuming the proper feed rate so as not to chip or melt the plastic. Half inch shank bits are recommended as acrylic is remarkably tough stuff. Concerning "gluing" acrylic, the primary solvent used is metheleyne chloride, along with some other ingredients to speed up or slow down the setting process, and rid the process of bubbles. This "glue" is the consistency of water and if used properly needs no vacuum process to give excellent bubble free results. IMHO,the group may want to consider, (if they haven't already done so)having a plastics shop in the vicinity of the machinist's location rough cut and laminate the acrylic sheet.Unless of course the machinist is experienced in these things. The "gluing" process is a bit tricky, and poor results are easily achieved.(I speak from experience here.) ;-) Hope this sheds some light on the situation. The acrylic plinths being considered by some in the group can be easily achieved by cutting and shaping a pattern of wood. Use double sided masking tape attach the acrylic to the pattern. Trim closely to within 1/4" of the pattern. and then rout with a flush cut bit on your router table! I welcome any questions and comments ( jolly, rude or otherwise)concerning my sermon here. I would like to offer my greatest thanks for the opportunity to be a benificiary of this great collection of insights and ideas. Michael LaRosa Subject: Re: [teres] Re: My two cents after reading the attached digests Date: Sat, 12 Feb 2000 23:40:27 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com; Stewart Ono; Micheal Larosa For those who came in lately, and didn't catch this in in previous posts (I don't know if this is in the digests): There is quite an assortment of VCR pinch rollers available from Parts Express & other sources. They are quite inexpensive, and should be investigated as possible bearings for insertrion into idler pulley assemblies. See old posts for details. Igor --- Thom Mackris / Joan Panzella wrote: > Hi Michael, > > I think I addressed all but one item from your > earlier e-mail. Note that > I'm copying you and Stu Ono in addition to the list, > as I believe that both > of you have still not been successful in > subscribing. Direct any questions > or problems you might have to Roscoe at his > "administrator's" address: > owner-teres@aiko.com > > The only unanswered question has to do with the > pulleys. > > The motor pulley will be addressed as part of the > motor design, and it is > highly probable that Bryce will be machining them. > The original thinking > was to make them of acrylic in order to maintain the > same thermal expansion > (relative speed accuracy) rate as the platter. With > Manfred's design > however, this may no longer be an issue. We will > certainly kick this design > around in the coming weeks. > > The whole issue of whether to incorporate idler > pulley(s) into the design is > also open at the moment, and will certainly play a > part in the motor and > subchassis dialogs. I think folks will split into a > two camps: (a) one > group favoring idlers and (b) the KISS group which > won't. > > Fortunately, this part of the project is totally > flexible. > > My concern about doing idler pulleys is that I think > they must be done > impeccably or not at all. I may just wait and stand > on the shoulders of > someone else's ambitious efforts before tackling it > myself. It seems as if > the safe bet is to machine the pulleys for later use > even if one chooses to > not explore this approach initially. Sourcing > bearings for the pulleys will > certainly be a challenge. Johannes Chiu > (http://www.columbia.edu/~jsc19/turntable.html) used > VCR heads as idler > pulleys (in contact with the platter !!) to add > rotational inertia to the > platter without adding weight. These heads are > apparently quite high > quality as far as their bearings are concerned. > > Johannes has some interesting ideas, and it would be > interesting to return > to them two months after directing the list to his > website. > > Cheers, > Thom > > > ----- Original Message ----- > From: Micheal Larosa > To: > Sent: Friday, February 11, 2000 3:22 AM > Subject: My two cents after reading the attached > digests > > > After reading through the digests I have a few > questions and comments. > > questions: > > What size is the thread on the outside of the brass > bearing? > > Will the spindle tips (threaded for clamp and non > threaded versions) have > flats machined on them to facilitate ease of > insertion and removal? > > Any idea on the diameter of the pulley and idlers? > > comments: > > I worked in a plastics shop for three years. during > wich i did most of the > acrylic work there. > > Concerning cutting and forming:Cutting is best > performed with a table saw > and a carbide tipped blade with a two to three deg. > negative rake.Care must > be taken to feed the saw at the appropriate > rate,otherwise > binding,melting,or chipping may result.(binding is > definitely a problem as > 1" acrylic is extremely thick and is not recommended > for beginners!)It's > also very heavy. I.E. two people are a must when > putting a 4'x8' sheet on > the table saw! > > Forming can be done with a typical router and > carbide bits used for > woodworking, again assuming the proper feed rate so > as not to chip or melt > the plastic. > Half inch shank bits are recommended as acrylic is > remarkably tough stuff. > > Concerning "gluing" acrylic, the primary solvent > used is metheleyne > chloride, along with some other ingredients to speed > up or slow down the > setting process, and rid the process of bubbles. > This "glue" is the consistency of water and if used > properly needs no vacuum > process to give excellent bubble free results. > > IMHO,the group may want to consider, (if they > haven't already done so)having > a plastics shop in the vicinity of the machinist's > location rough cut and > laminate the acrylic sheet.Unless of course the > machinist is experienced in > these things. The "gluing" process is a bit tricky, > and poor results are > easily achieved.(I speak from experience here.) ;-) > > Hope this sheds some light on the situation. > > The acrylic plinths being considered by some in the > group can be easily > achieved by cutting and shaping a pattern of wood. > Use double sided masking > tape attach the acrylic to the pattern. Trim closely > to within 1/4" of the > pattern. and then rout with a flush cut bit on your > router table! > > I welcome any questions and comments ( jolly, rude > or otherwise)concerning > my sermon here. > > I would like to offer my greatest thanks for the > opportunity to be a > benificiary of this great collection of insights and > ideas. > > Michael LaRosa > > > > > __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com Subject: Re: [teres] Teres: Subchassis & Armboard Date: Mon, 14 Feb 2000 18:22:55 -0700 From: MaughanAudio@aol.com, MaughanAudio@aol.com To: teres@aiko.com My views on the platter bearing support and overall suspension is . . . use and X or a Y pattern. The intersection of either shape is the center point for the bearing mount. The arms of the X or Y would then create a four or three point support base. Advantages are: 1) radiating pathways for vibrational energy. 2) the most mass is concentrated at the bearing junction ( best for reducing resonances and reflected energies. 3) reduction of flat planner surfaces under the platter that would reflect energy back. As for the suspension, many options could be discussed and depending on the supporting flooring for the specific install that would determine which might be best. The main point would be to design the end of the arms to receive serveral different treatments. The arm board, for my system, I plan on using a large solid block of copper ( if affordable ) or a chunk of aluminum and then milling out areas for a tube phono preamp in the arm board. But for an interum design and one more acceptable to most would be to simply laminate different materials such as Corian, aluminum, masonite to create a massive inert structure for the arm mount. This assembly would stradle across two of the base arms. A simple gasket of lossey material would decouple vibrational energy from the base to the arm "block" assembly. I will make drawings up in Autocad but do not know how to distribute in a format everone could view. Regarding the use of "wonderboard" concrete sheetrock. I've used the stuff and it is very economical for a massive board, but it has several problems. It's messy and crumbles easily at any cuts so one would have to enclose it to make a good looking base. Might as well use something that finishes nicely since the material won't be that large an area. Corian is excellent, it is expensive, but the small amount used especially laminating it with high density fiber board (HDF not MDF) and or massonite would make a very massive structure that would be practical for sinking and dampening vibrational energy. It is also easy to machine. Regarding vibrational energy, a flat plate is a poor choice. An example why is they made resonators for studios using large thin sheets of steel. Transducers would be placed at one point and then receivers at another point. The vibrational energy would tavel back and forth reflecting off the edges. The same happens (to a much lesser degree) in any object. The point is that the more distances are reduced the more these vibrational modes are raised and reduced in time. With a base shapped as an X these modes will be substantially incresed in fq. and reduced in time decay. Furthermore they will essentially be constrained to radiate towards the ends off the legs were if that point is properly sinked, little energy will reflect back. Subject: Re: [teres] Teres: Subchassis & Armboard Date: Mon, 14 Feb 2000 21:19:09 -0700 From: Ron Welborne, Ron Welborne To: teres@aiko.com Gordon, I suspect you're probably right about using an X-Y platform for the base. However, we're getting into cosmetics now and it should be interesting to see the different directions people take. I was just reading the latest literature from Well Tempered and their Reference table uses Fountainhead (another material choice). They use two thick layers separated by small isolation feet (sorbothane?) and they claim a subsonic resonant frequency for the table. Their cheaper tables use 3 or 4 one inch layers of MDF each isolated with the same feet. This type of sandwich design could also be applied to an X-Y platform. Another option for the motor base is lead. It might be easier and cheaper to make a quick and dirty mold, start a fire in the backyard and have a lead melting party! Attached (I hope this is legal?) is a .jpg of an interesting item I received literature on today. They're called the Feet of Silence. They are vibration control pods designed to control internal and external vibrations. The base is machined aluminum. It uses O-rings for the suspension (a total of 6) providing both vertical and horizontal movement. The internal platform (called the Vibration Absorber) absorbs internally induced vibrations. At the top of the Vibration Absorber is a steel ball bearing which is the equipment contact point. They are sold in sets of three and can support 5-15kg or 10-40kg. These things might just support the weight of a turntable! Ron Welborne Labs wlabs@ix.netcom.com ph: 303.470.6585 fax: 303.791.5783 website --------------- www.welbornelabs.com ----------------- ----- Original Message ----- From: To: Sent: Monday, February 14, 2000 5:17 PM Subject: Re: [teres] Teres: Subchassis & Armboard > My views on the platter bearing support and overall suspension is . . . > use and X or a Y pattern. The intersection of either shape is the center > point for the bearing mount. The arms of the X or Y would then create a four > or three point support base. Advantages are: > 1) radiating pathways for vibrational energy. > 2) the most mass is concentrated at the bearing junction ( best for reducing > resonances and reflected energies. > 3) reduction of flat planner surfaces under the platter that would reflect > energy back. > As for the suspension, many options could be discussed and depending on the > supporting flooring for the specific install that would determine which might > be best. > The main point would be to design the end of the arms to receive serveral > different treatments. > The arm board, for my system, I plan on using a large solid block of copper > if affordable ) or a chunk of aluminum and then milling out areas for a tube > phono preamp in the arm board. But for an interum design and one more > acceptable to most would be to simply laminate different materials such as > Corian, aluminum, masonite to create a massive inert structure for the arm > mount. This assembly would stradle across two of the base arms. A simple > gasket of lossey material would decouple vibrational energy from the base to > the arm "block" assembly. I will make drawings up in Autocad but do not know > how to distribute in a format everone could view. > Regarding the use of "wonderboard" concrete sheetrock. I've used the > stuff and it is very economical for a massive board, but it has several > problems. It's messy and crumbles easily at any cuts so one would have to > enclose it to make a good looking base. Might as well use something that > finishes nicely since the material won't be that large an area. Corian is > excellent, it is expensive, but the small amount used especially laminating > it with high density fiber board (HDF not MDF) and or massonite would make a > very massive structure that would be practical for sinking and dampening > vibrational energy. It is also easy to machine. > Regarding vibrational energy, a flat plate is a poor choice. An example > why is they made resonators for studios using large thin sheets of steel. > Transducers would be placed at one point and then receivers at another point. > The vibrational energy would tavel back and forth reflecting off the edges. > The same happens (to a much lesser degree) in any object. The point is that > the more distances are reduced the more these vibrational modes are raised > and reduced in time. With a base shapped as an X these modes will be > substantially incresed in fq. and reduced in time decay. Furthermore they > will essentially be constrained to radiate towards the ends off the legs were > if that point is properly sinked, little energy will reflect back. --------------------------------------------------------------------- Name: feet.jpg feet.jpg Type: JPEG Image (image/jpeg) Encoding: base64 Subject: Re: [teres] Teres: Subchassis & Armboard Date: Tue, 15 Feb 2000 13:42:28 -0700 From: Ivan Anderson, Ivan Anderson To: teres@aiko.com Hi Chris, > Wonderboard > if you have not seen it is essentially concrete that is > made into sheets held together with a fiber mesh. It is > used as a base for ceramic tile and comes in several > thicknesses. Has anyone tried this stuff? It seems > promising but I have never used it. Here in NZ and Aust we have a similar product that is used as a flooring base for tiles etc. It is called Hardipanel and is made of compressed fibre cement. It comes in various sheet sizes up to 24mm thick, and is extremely dense, very heavy and has a smooth finish. The sheets can be worked much as MDF or HDF except one uses a masonary wheel instead of a saw blade and carbide drills. The edges can be chamfered with a file or angle grinder. The sheets look fine with a coat of paint. I haved used this as shelves when I had my audio furniture business in Aust. and they outperformed the basic MDF shelf by a large degree. I had occasion to use a large sheet on the floor of a house with springy floor boards... just gave it a large chamfer a coat of paint and chucked it on top of the carpet... instant concrete slab. This was so successful that I had many orders and stuffed my back! As shelves they were quite good, but better were granite and marble (I prefered granite) and an extremely light but very rigid board I used to make. This was fashioned from Divinycel, a closed cell polyvinyl foam sheet used in boat building, laminated both sides with Formica, using an epoxy glue saturated with fock. I could sell this board to anyone just by placing it under a CDP or turntable, the improvement in sound was great enough to impress even the cloth ears among us. But the best board I have made used both density and lightness. Granite or marble base - Divinycel - Formica. These boards were not cheap, but the way they extended the frequency extremes and improved the coherence of the music meant that there was a ready market for them. Improvements were found under all pieces in the reproduction chain, but I was quite surprised at the change effected under ss power amps. This is what I will use as a subchasis in the long run, but I will probably experiment with Hardipanel sandwiches to find the optimum shape etc. Regards Ivan. Subject: Re: [teres] Teres: Subchassis & Armboard Date: Tue, 15 Feb 2000 14:18:27 -0700 From: Jeremy Epstein, Jeremy Epstein To: teres@aiko.com Chris Brady wrote: > > Since we are not far away from having turntable parts in > hand :) I am anxious to get at least a first cut of a > subchassis figured out. I was thinking that a sandwich of > MDF and "wonderboard" may make a good base. Wonderboard > if you have not seen it is essentially concrete that is > made into sheets held together with a fiber mesh. It is > used as a base for ceramic tile and comes in several > thicknesses. Has anyone tried this stuff? It seems > promising but I have never used it. It's very dense, and is quite a bit less crumbly than drywall and cuts slightly more crisply. It is probably the substance that dulls tools the fastest of any I have ever worked - it's not just the concrete, the mesh is tough and the whole inside has sort of a resinous quality too - it's meant to be used in wet locations like bathrooms so it is more waterproof than drywall. You would want to coat its edges with something like epoxy or duct tape if they were exposed because they would be a little crumbly still. I don't know how it would work in this application. -j -- ========================================= Jeremy Epstein .........jepstein@shwd.com ========================================= Subject: RE: [teres] Teres: Subchassis & Armboard Date: Tue, 15 Feb 2000 14:40:26 -0700 From: Fritz Moore, Fritz Moore To: teres@aiko.com I think we may be able to improve beyond wonderboard. Im not sure it is as dense as it could be it may have an expander in it. We might be able to mix up a concrete product that is denser and would pour into a void or base. There are a lot of concrete modifiers now days we might be able to produce a wet mix that is denser than wonderboard and fits perfectly inside a base, some of the acrylic modifiers even move it towards an elastic material that might damp better. There are cement /acrylic materials for setting tile that might fit this description. Fritz -----Original Message----- From: owner-teres@aiko.com [mailto:owner-teres@aiko.com]On Behalf Of Jeremy Epstein Sent: Tuesday, February 15, 2000 10:55 AM To: teres@aiko.com Subject: Re: [teres] Teres: Subchassis & Armboard Chris Brady wrote: > > Since we are not far away from having turntable parts in > hand :) I am anxious to get at least a first cut of a > subchassis figured out. I was thinking that a sandwich of > MDF and "wonderboard" may make a good base. Wonderboard > if you have not seen it is essentially concrete that is > made into sheets held together with a fiber mesh. It is > used as a base for ceramic tile and comes in several > thicknesses. Has anyone tried this stuff? It seems > promising but I have never used it. It's very dense, and is quite a bit less crumbly than drywall and cuts slightly more crisply. It is probably the substance that dulls tools the fastest of any I have ever worked - it's not just the concrete, the mesh is tough and the whole inside has sort of a resinous quality too - it's meant to be used in wet locations like bathrooms so it is more waterproof than drywall. You would want to coat its edges with something like epoxy or duct tape if they were exposed because they would be a little crumbly still. I don't know how it would work in this application. -j -- ========================================= Jeremy Epstein .........jepstein@shwd.com ========================================= Subject: RE: [teres] Teres: Subchassis & Armboard Date: Tue, 15 Feb 2000 15:27:27 -0700 From: Schei, Kenneth, Schei, Kenneth To: 'teres@aiko.com' I still like the idea of building a good master mold and casting our base out of a concrete-like product. There is a multitude of epoxy-type concrete products that we could use. We have the option of adding additives that would make the mix denser, less dense, etc. to suite our needs. We also may want to consider some of Ennimoser's ideas and make our base out of carbon-based materials. Ennimoser claims that since were carbon-based beings, the sonic signature of carbon-based structures sound the most pleasant to our ears. I agree with him wholeheartedly. The reasoning is that we will never be able to completely eliminate the sonic signature of the base, so we should strive to: 1) Minimize it, and 2) Make the residual signature as benign as possible. MDF is a carbon-based product which is probably one reason why it finds so many applications in audio. Adding carbon to our concrete mixes would also be very effective. I finish all of my components with shellac, which is made from the shells of the lac bug, as carbon-based as you can get. Tung oil is also a good carbon-based finish. Polyurethane shouldn't sound as good (have you ever heard of a polyurethane-finished violin?) although I'll agree with Thom that it resists cat pee better. The pedestal for my amplifier is a rough commercial concrete column that I finished with a hand-rubbed shellac finish; it looks dynamite. I wouldn't mind having a carbon-filled concrete TT deck with a hand-rubbed shellac finish. Just some thoughts. Ken Ken Schei, P.E. Project Engineer Antarctic Support Associates Email address: scheike@asa.org Phone: 303-643-0163 > -----Original Message----- > From: Fritz Moore [SMTP:fbmoore@ucdavis.edu] > Sent: Tuesday, February 15, 2000 1:38 PM > To: teres@aiko.com > Subject: RE: [teres] Teres: Subchassis & Armboard > > I think we may be able to improve beyond wonderboard. Im not sure > it is as > dense as it could be it may have an expander in it. We might be able to > mix > up a concrete product that is denser and would pour into a void or base. > There are a lot of concrete modifiers now days we might be able to produce > a > wet mix that is denser than wonderboard and fits perfectly inside a base, > some of the acrylic modifiers even move it towards an elastic material > that > might damp better. There are cement /acrylic materials for setting tile > that might fit this description. > > Fritz > > -----Original Message----- > From: owner-teres@aiko.com [mailto:owner-teres@aiko.com]On Behalf Of > Jeremy Epstein > Sent: Tuesday, February 15, 2000 10:55 AM > To: teres@aiko.com > Subject: Re: [teres] Teres: Subchassis & Armboard > > > Chris Brady wrote: > > > > Since we are not far away from having turntable parts in > > hand :) I am anxious to get at least a first cut of a > > subchassis figured out. I was thinking that a sandwich of > > MDF and "wonderboard" may make a good base. Wonderboard > > if you have not seen it is essentially concrete that is > > made into sheets held together with a fiber mesh. It is > > used as a base for ceramic tile and comes in several > > thicknesses. Has anyone tried this stuff? It seems > > promising but I have never used it. > > It's very dense, and is quite a bit less crumbly than drywall and cuts > slightly more crisply. It is probably the substance that dulls tools the > fastest of any I have ever worked - it's not just the concrete, the mesh > is tough and the whole inside has sort of a resinous quality too - it's > meant to be used in wet locations like bathrooms so it is more > waterproof than drywall. You would want to coat its edges with something > like epoxy or duct tape if they were exposed because they would be a > little crumbly still. > > I don't know how it would work in this application. > > -j > -- > ========================================= > Jeremy Epstein .........jepstein@shwd.com > ========================================= Subject: Re: [teres] Teres: Subchassis & Armboard Date: Tue, 15 Feb 2000 17:55:40 -0700 From: MaughanAudio@aol.com, MaughanAudio@aol.com To: teres@aiko.com The idea of molded concrete resins expounded by Ken Schei's comments on carbon additives and compounds make a lot of sense. What I had written earlier may have been lost to the bit bucket. So I'll reattach with the comment that a poured resin in a mold using the "X" or "Y" pattern instead of a 3 or four sided shape would be an excellent option. Here is the original . . . My views on the platter bearing support and overall suspension is . . . use an X or a Y pattern. The intersection of either shape is the center point for the bearing mount. The arms of the X or Y would then create a four or three point support base. Advantages are: 1) radiating pathways for vibrational energy. 2) The greatest mass is concentrated at the bearing junction (best for reducing resonances and reflected energies). 3) Reduction of flat planner surfaces under the platter that would reflect energy back. As for the suspension, many options could be discussed and depending on the supporting floor, for the specific install, would determine which might be best. The main point would be to design the end of the arms to receive several different treatments. The arm board, for my system, I plan on using a large solid block of copper (if affordable) or a chunk of aluminum and then milling out areas for a tube phono preamp in the arm board. But for an interim design and one more acceptable to most would be to simply laminate different materials such as Corian, aluminum, masonite to create a massive inert structure for the arm mount. This assembly would straddle across two of the base arms. A simple gasket of lossey material would decouple vibrational energy from the base to the arm "block" assembly. From other notes a more desirable option might be to lock the arm booard to the base arm to increase the mass of the arm board and to couple it to the platter unit. Regarding the use of "wonderboard" concrete sheetrock. I've used the stuff and it is very economical for a massive board, but it has several problems. It's messy and crumbles easily at any cuts. So one would have to enclose it to make a good looking base. Might as well use something that finishes nicely since the material won't be that large an area. Corian is excellent, it is expensive, but the small amount used especially laminating it with high density fiber board (HDF not MDF) and or massonite would make a very massive structure that would be practical for sinking and dampening vibrational energy. It is also easy to machine. Regarding vibrational energy, a flat plate is a poor choice. An example why is they made resonators for studios using large thin sheets of steel. Transducers would be placed at one point and then receivers at another point. The vibrational energy would travel back and forth reflecting off the edges. The same happens (to a much lesser degree) in any object. The point is that the more distances are reduced the more these vibrational modes are raised and reduced in time. With a base shaped as an X these modes will be substantially increased in fq. and reduced in time decay. Furthermore vibrational energy will be constrained to radiate towards the ends of the legs. If that point is properly sinked, little energy will reflect back. Subject: Re: [teres] Teres: Subchassis & Armboard Date: Tue, 15 Feb 2000 20:19:20 -0700 From: Ivan Anderson, Ivan Anderson To: teres@aiko.com Igor, That should have read flock, I don't care to speculate what 'fock' is, but it sounds Scottish. Flock is added to epoxy resin to stiffen and thicken, so that the glue will bridge gaps and not run. The flock I used consisted mainly of cotton fibres or fluff and some kaolin powder, if my memory serves. Please visit this page for a description of epoxy glues and their use. http://www.concentric.net/~westsys/technical/user_man.shtml I began laminating these boards piece by piece originally, but ended up doing whole sheets. 12 mm Divinycel and 1mm Formica. Once laminated the board is as light as a feather but impossible to bend. However one must be careful of spikes and the pointed end of cones as it is possible to break through the Formica... I would bluetack copper coins in place to prevent this, alas these are no longer in circulation. If you require further information just ask. Regards Ivan. ----- Original Message ----- From: "Igor Kuznetsoff" > --- Ivan Anderson wrote: > >This was fashioned from Divinycel, a closed > > cell polyvinyl foam sheet > > used in boat building, laminated both sides with > > Formica, using an epoxy > > glue saturated with fock. > > Ivan, > More info on this, please. What is fock? > > Igor Subject: Re: [teres] Teres: Subchassis & Armboard Date: Tue, 15 Feb 2000 21:38:55 -0700 From: Ivan Anderson, Ivan Anderson To: teres@aiko.com Ken, The composition of the human body is by weight: Oxygen 65% Carbon 18% Hydrogen 10% There are then, about 3 times as many oxygen atoms as carbon atoms, and about 6.5 times as many hydrogen atoms as carbon. If we were to sum the vibration of the molecules in our bodies the most dominant would be the vibration of water I should think. The reason that MDF is used so much in audio applications is , to my mind, it's cheap, it's easy to work, it sounds ok and it's cheap. The structural integrity of MDF is due to the liberal amount of glue with which it is formed. Petrochemicals from which many synthetic products are wrought is carbon based. There is probably more carbon in polyurethane than wood. The sonic signature of a substance has depends upon its structural make-up, which ultimately depends upon its constituent elements of course, but more in the molecular arrangement of its constituents rather than just their presence. Apart from that I agree wholeheartedly ;-) Cheers Ivan. ----- Original Message ----- From: "Schei, Kenneth" To: Sent: Wednesday, 16 February 2000 10:29 Subject: RE: [teres] Teres: Subchassis & Armboard > I still like the idea of building a good master mold and casting our base > out of a concrete-like product. There is a multitude of epoxy-type concrete > products that we could use. We have the option of adding additives that > would make the mix denser, less dense, etc. to suite our needs. We also may > want to consider some of Ennimoser's ideas and make our base out of > carbon-based materials. Ennimoser claims that since were carbon-based > beings, the sonic signature of carbon-based structures sound the most > pleasant to our ears. I agree with him wholeheartedly. The reasoning is > that we will never be able to completely eliminate the sonic signature of > the base, so we should strive to: 1) Minimize it, and 2) Make the > residual signature as benign as possible. MDF is a carbon-based product > which is probably one reason why it finds so many applications in audio. > Adding carbon to our concrete mixes would also be very effective. I finish > all of my components with shellac, which is made from the shells of the lac > bug, as carbon-based as you can get. Tung oil is also a good carbon-based > finish. Polyurethane shouldn't sound as good (have you ever heard of a > polyurethane-finished violin?) although I'll agree with Thom that it resists > cat pee better. The pedestal for my amplifier is a rough commercial > concrete column that I finished with a hand-rubbed shellac finish; it looks > dynamite. I wouldn't mind having a carbon-filled concrete TT deck with a > hand-rubbed shellac finish. Just some thoughts. > > Ken > > Ken Schei, P.E. > Project Engineer > Antarctic Support Associates > Email address: scheike@asa.org > Phone: 303-643-0163 > > Subject: [teres] Carbon based materials Date: Tue, 15 Feb 2000 23:35:49 -0700 From: Sellek, Grant (TSA), Sellek, Grant (TSA) To: 'teres@aiko.com' Whether I agree philosophically with Ennemoser or not, I am not sure whether Ken misrepresents the notions. "the sonic signature of carbon-based structures sound the most pleasant to our ears." I therefore conclude that all plastics belong on the "most favoured" list, because they are certainly molecularly carbon-based, and many plastics find their ancestry in naturally-occuring oils that were once flora and fauna, our own "carbon-based life forms". Why oh why did I ever sell those bextrene and polypropylene cones? Perhaps Ennemoser meant cellular materials? That would explain the preference for paper over plastic. If plastics don't qualify for Ennerfavouritism, we on the Teres list have a small problem: what to do about those vinyl sound signatures? I know - spray them with Ennerlacquer! (for those who don't know, it exists and is called C37. Don't even ask about the price) Either way, I think adding carbon to concrete mix is a long way from implementing Ennerphilosophy. Grant PS Ken, are you going to coat your acrylic Teres platter with shellac? (I'm not being sarcastic) Grant Sellek Adelaide, Australia grant.sellek@transport.sa.gov.au -----Original Message----- From: Schei, Kenneth [mailto:SCHEIKE@asa.org] Sent: Wednesday, 16 February 2000 7:59 am To: 'teres@aiko.com' Subject: RE: [teres] Teres: Subchassis & Armboard Importance: Low I still like the idea of building a good master mold and casting our base out of a concrete-like product. There is a multitude of epoxy-type concrete products that we could use. We have the option of adding additives that would make the mix denser, less dense, etc. to suite our needs. We also may want to consider some of Ennimoser's ideas and make our base out of carbon-based materials. Ennimoser claims that since were carbon-based beings, the sonic signature of carbon-based structures sound the most pleasant to our ears. I agree with him wholeheartedly. The reasoning is that we will never be able to completely eliminate the sonic signature of the base, so we should strive to: 1) Minimize it, and 2) Make the residual signature as benign as possible. MDF is a carbon-based product which is probably one reason why it finds so many applications in audio. Adding carbon to our concrete mixes would also be very effective. I finish all of my components with shellac, which is made from the shells of the lac bug, as carbon-based as you can get. Tung oil is also a good carbon-based finish. Polyurethane shouldn't sound as good (have you ever heard of a polyurethane-finished violin?) although I'll agree with Thom that it resists cat pee better. The pedestal for my amplifier is a rough commercial concrete column that I finished with a hand-rubbed shellac finish; it looks dynamite. I wouldn't mind having a carbon-filled concrete TT deck with a hand-rubbed shellac finish. Just some thoughts. Ken Ken Schei, P.E. Project Engineer Antarctic Support Associates Email address: scheike@asa.org Phone: 303-643-0163 Subject: RE: [teres] Teres: Subchassis & Armboard Date: Tue, 15 Feb 2000 23:57:46 -0700 From: Sellek, Grant (TSA), Sellek, Grant (TSA) To: 'teres@aiko.com' Ivan, I believe Ennemoser was most keenly interested in the resonant qualities of the human ear, so he focused on the "sound of human bone", not so much on the average elemental proportions of the human body. He theorised that the human brain must mask the innate sonic qualities of the mechanisms of the human ear, otherwise everything would sound like buzzing bones, so if the instrument's material and construction (he manufactures violins that are very nonconformist but highly regarded) has a sonic signature similar to that of the internal human ear, then the brain will mask it out. He applies his thoeries successfully to his instruments, and I think (this is all from memory) he also makes some speaker drivers. I have some sympathy with the central idea. And I think the whole notion is even more crucial in audio than in musical instruments. Grant -----Original Message----- From: Ivan Anderson If we were to sum the vibration of the molecules in our bodies the most dominant would be the vibration of water I should think. Subject: Re: [teres] Teres: Subchassis & Armboard Date: Wed, 16 Feb 2000 00:13:56 -0700 From: Thom Mackris / Joan Panzella, Thom Mackris / Joan Panzella To: teres@aiko.com You sum up Dieter's premise the way I understand it, Grant. Masking does indeed play an important part in designing components. If his theory gets you bent out of shape, then prepare yourself for a really wild ride - Peter Belt: http://www.belt.demon.co.uk/ Please take the following in the humorous spirit in which it's offered... All of the rationale we hear, especially in consumer audio reminds me of a satirical add I saw in National Lampoon for a mythical product called the Earth Tire. Those of you who are baby boomers and older might remember the "hippy dippy" shoe called the Earth Shoe, designed by Anne Kalso. The heel was lower than the (raised) forefoot area. She spoke of life-like bounce that you got from wearing her shoes, etc. etc. Anyhow, the Earth Tire (satirical add) was about a hexagonally shaped tire which gave your car a life-like bounce. Their motto was "remember - a tire that's flat on only one side isn't an Earth Tire". Cheers, Thom ----- Original Message ----- From: Sellek, Grant (TSA) To: Sent: Tuesday, February 15, 2000 10:55 PM Subject: RE: [teres] Teres: Subchassis & Armboard Ivan, I believe Ennemoser was most keenly interested in the resonant qualities of the human ear, so he focused on the "sound of human bone", not so much on the average elemental proportions of the human body. He theorised that the human brain must mask the innate sonic qualities of the mechanisms of the human ear, otherwise everything would sound like buzzing bones, so if the instrument's material and construction (he manufactures violins that are very nonconformist but highly regarded) has a sonic signature similar to that of the internal human ear, then the brain will mask it out. He applies his thoeries successfully to his instruments, and I think (this is all from memory) he also makes some speaker drivers. I have some sympathy with the central idea. And I think the whole notion is even more crucial in audio than in musical instruments. Grant -----Original Message----- From: Ivan Anderson If we were to sum the vibration of the molecules in our bodies the most dominant would be the vibration of water I should think. Subject: Re: [teres] Teres: Subchassis & Armboard Date: Wed, 16 Feb 2000 00:29:58 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com Ivan, Thanks. I actually already have some kaolin-based thickener among my shelves of materials, resins & glues. I was not aware of Divynicel, and am always excited by useful new materials. I appreciate the website, tx. I was curious about what the "fock" might be, and, yes, it does sound rather scrottish. Igor --- Ivan Anderson wrote: > Igor, > > That should have read flock, I don't care to > speculate what 'fock' is, but > it sounds Scottish. > > Flock is added to epoxy resin to stiffen and > thicken, so that the glue will > bridge gaps and not run. The flock I used consisted > mainly of cotton fibres > or fluff and some kaolin powder, if my memory > serves. Please visit this > page for a description of epoxy glues and their use. > http://www.concentric.net/~westsys/technical/user_man.shtml > > I began laminating these boards piece by piece > originally, but ended up > doing whole sheets. 12 mm Divinycel and 1mm Formica. > Once laminated the > board is as light as a feather but impossible to > bend. However one must be > careful of spikes and the pointed end of cones as it > is possible to break > through the Formica... I would bluetack copper coins > in place to prevent > this, alas these are no longer in circulation. > > If you require further information just ask. > > Regards > Ivan. > > > > ----- Original Message ----- > From: "Igor Kuznetsoff" > > > --- Ivan Anderson wrote: > > >This was fashioned from Divinycel, a closed > > > cell polyvinyl foam sheet > > > used in boat building, laminated both sides with > > > Formica, using an epoxy > > > glue saturated with fock. > > > > Ivan, > > More info on this, please. What is fock? > > > > Igor > > > __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com Subject: Re: [teres] Teres: Subchassis & Armboard Date: Wed, 16 Feb 2000 03:28:54 -0700 From: Ivan Anderson, Ivan Anderson To: teres@aiko.com Thanks Grant, Ken's message makes more sense now. (sorry Ken) I imagine that the application of this theory is a bit more complicated than the simple addition of carbon or use of biologically based materials... but who knows... I am generally short on theory and long on 'suck it and see'. Ivan. ----- Original Message ----- From: "Sellek, Grant (TSA)" To: Sent: Wednesday, 16 February 2000 18:55 Subject: RE: [teres] Teres: Subchassis & Armboard > Ivan, I believe Ennemoser was most keenly interested in the resonant > qualities of the human ear, so he focused on the "sound of human bone", not > so much on the average elemental proportions of the human body. He theorised > that the human brain must mask the innate sonic qualities of the mechanisms > of the human ear, otherwise everything would sound like buzzing bones, so if > the instrument's material and construction (he manufactures violins that are > very nonconformist but highly regarded) has a sonic signature similar to > that of the internal human ear, then the brain will mask it out. He applies > his thoeries successfully to his instruments, and I think (this is all from > memory) he also makes some speaker drivers. > > I have some sympathy with the central idea. And I think the whole notion is > even more crucial in audio than in musical instruments. > > Grant Subject: RE: [teres] Teres: Subchassis & Armboard Date: Wed, 16 Feb 2000 09:24:09 -0700 From: Kalman Rubinson, Kalman Rubinson To: 'teres@aiko.com' On Wed, 16 Feb 2000, Sellek, Grant (TSA) wrote: > Ivan, I believe Ennemoser was most keenly interested in the resonant > qualities of the human ear, so he focused on the "sound of human bone", not > so much on the average elemental proportions of the human body. He theorised > that the human brain must mask the innate sonic qualities of the mechanisms > of the human ear, otherwise everything would sound like buzzing bones, so if > the instrument's material and construction (he manufactures violins that are > very nonconformist but highly regarded) has a sonic signature similar to > that of the internal human ear, then the brain will mask it out. This is silly. The bones are damped by their ligaments and dynamically controlled by muscle action. Besides, the dimensions of the bones involved are so small that any resonances are very(!) high. > I have some sympathy with the central idea. And I think the whole notion is > even more crucial in audio than in musical instruments. I have no sympathy for the idea. Is there anything experimental to support it? Are there prosthetic bones with differing resonant characteristics which are less well adapted? I think you'll find that the adaptive mechanisms of the human brain are so capable (and pervasive) that this cannot be relevant. Kal Subject: RE: [teres] Teres: Subchassis & Armboard Date: Wed, 16 Feb 2000 09:44:04 -0700 From: Schei, Kenneth, Schei, Kenneth To: 'teres@aiko.com' Ivan: Thanks for your feedback. I should have been more precise. I agree that in addition to the proper chemical components, the physical composition has to be right. One of the properties of carbon, to which you and I can attribute our existance, is that it combines with other elements in many, many different ways. What Ennimoser is really championing is Carbon 37, a carbon composition that is the one of the primary components of human (and all animal) bone. There is a bony protrusion right behind your ear; try rapping on it with your knuckle. The sound you hear is the sound of C-37, and is the benign tone that we are seeking. Try rapping on a good MDF speaker enclosure and you will hear a somewhat similar tone, but not as good. The other major component of bone is calcium, of course. My use of shellac as a finishing material for my components is based on the fact that shellac is made from the ground-up carapaces of the lac bug, which have the same composition as bone. Shellac is dissolved in alcohol, which is also a carbon-based product. My two speakers have almost 6000 square inches of surface area finished with shellac, which is a significant contribution to their sound. It's also no accident that the cones of Lowther speakers are coated with shellac. Although polyurethane does contain carbon, it isn't really the same, IMHO. Neither the chemical nor physical composition is right. Common Portland cement is high in calcium, so if we add carbon as a filler, the finished casting will have a chemical composition similar to human bone, and the physical structure also will resemble bone. A hand-rubbed shellac finish will penetrate the surface and produce a hard shell very similar to the surface of a human bone. That's really what I was getting at, and I think that it would be worth striving for. Cheers, Ken Ken Schei, P.E. Project Engineer Antarctic Support Associates Email address: scheike@asa.org Phone: 303-643-0163 > -----Original Message----- > From: Ivan Anderson [SMTP:ivan@win.co.nz] > Sent: Tuesday, February 15, 2000 8:33 PM > To: teres@aiko.com > Subject: Re: [teres] Teres: Subchassis & Armboard > > Ken, > > The composition of the human body is by weight: > Oxygen 65% > Carbon 18% > Hydrogen 10% > There are then, about 3 times as many oxygen atoms as carbon atoms, and > about 6.5 times as many hydrogen atoms as carbon. > > If we were to sum the vibration of the molecules in our bodies the most > dominant would be the vibration of water I should think. > > The reason that MDF is used so much in audio applications is , to my mind, > it's cheap, it's easy to work, it sounds ok and it's cheap. The structural > integrity of MDF is due to the liberal amount of glue with which it is > formed. > > Petrochemicals from which many synthetic products are wrought is carbon > based. There is probably more carbon in polyurethane than wood. > > The sonic signature of a substance has depends upon its structural > make-up, > which ultimately depends upon its constituent elements of course, but more > in the molecular arrangement of its constituents rather than just their > presence. > > Apart from that I agree wholeheartedly ;-) > > Cheers > Ivan. > > ----- Original Message ----- > From: "Schei, Kenneth" > To: > Sent: Wednesday, 16 February 2000 10:29 > Subject: RE: [teres] Teres: Subchassis & Armboard > > > > I still like the idea of building a good master mold and casting our > base > > out of a concrete-like product. There is a multitude of epoxy-type > concrete > > products that we could use. We have the option of adding additives that > > would make the mix denser, less dense, etc. to suite our needs. We also > may > > want to consider some of Ennimoser's ideas and make our base out of > > carbon-based materials. Ennimoser claims that since were carbon-based > > beings, the sonic signature of carbon-based structures sound the most > > pleasant to our ears. I agree with him wholeheartedly. The reasoning > is > > that we will never be able to completely eliminate the sonic signature > of > > the base, so we should strive to: 1) Minimize it, and 2) Make the > > residual signature as benign as possible. MDF is a carbon-based product > > which is probably one reason why it finds so many applications in audio. > > Adding carbon to our concrete mixes would also be very effective. I > finish > > all of my components with shellac, which is made from the shells of the > lac > > bug, as carbon-based as you can get. Tung oil is also a good > carbon-based > > finish. Polyurethane shouldn't sound as good (have you ever heard of a > > polyurethane-finished violin?) although I'll agree with Thom that it > resists > > cat pee better. The pedestal for my amplifier is a rough commercial > > concrete column that I finished with a hand-rubbed shellac finish; it > looks > > dynamite. I wouldn't mind having a carbon-filled concrete TT deck with > a > > hand-rubbed shellac finish. Just some thoughts. > > > > Ken > > > > Ken Schei, P.E. > > Project Engineer > > Antarctic Support Associates > > Email address: scheike@asa.org > > Phone: 303-643-0163 > > > > > Subject: RE: [teres] Carbon based materials Date: Wed, 16 Feb 2000 10:01:32 -0700 From: Schei, Kenneth, Schei, Kenneth To: 'teres@aiko.com' Grant: See my reply to Ivan where I clarified myself. To sum up, no, plastics aren't right, and au contraire, adding carbon to concrete mix and finishing the casting with shellac is indeed implimenting Ennemoser's philosophies. You don't have to embrace them or even agree, but try considering the full reasoning behind Ennemoser's and my ideas before you dismiss them. Cheers, Ken Ken Schei, P.E. Project Engineer Antarctic Support Associates Email address: scheike@asa.org Phone: 303-643-0163 > -----Original Message----- > From: Sellek, Grant (TSA) [SMTP:Grant.Sellek@transport.sa.gov.au] > Sent: Tuesday, February 15, 2000 10:32 PM > To: 'teres@aiko.com' > Subject: [teres] Carbon based materials > > Whether I agree philosophically with Ennemoser or not, I am not sure > whether > Ken misrepresents the notions. "the sonic signature of carbon-based > structures sound the most pleasant to our ears." I therefore conclude that > all plastics belong on the "most favoured" list, because they are > certainly > molecularly carbon-based, and many plastics find their ancestry in > naturally-occuring oils that were once flora and fauna, our own > "carbon-based life forms". Why oh why did I ever sell those bextrene and > polypropylene cones? > > Perhaps Ennemoser meant cellular materials? That would explain the > preference for paper over plastic. > > If plastics don't qualify for Ennerfavouritism, we on the Teres list have > a > small problem: what to do about those vinyl sound signatures? I know - > spray > them with Ennerlacquer! (for those who don't know, it exists and is called > C37. Don't even ask about the price) > > Either way, I think adding carbon to concrete mix is a long way from > implementing Ennerphilosophy. > > Grant > PS Ken, are you going to coat your acrylic Teres platter with shellac? > (I'm > not being sarcastic) > > Grant Sellek > Adelaide, Australia > grant.sellek@transport.sa.gov.au > > > -----Original Message----- > From: Schei, Kenneth [mailto:SCHEIKE@asa.org] > Sent: Wednesday, 16 February 2000 7:59 am > To: 'teres@aiko.com' > Subject: RE: [teres] Teres: Subchassis & Armboard > Importance: Low > > > I still like the idea of building a good master mold and casting our base > out of a concrete-like product. There is a multitude of epoxy-type > concrete > products that we could use. We have the option of adding additives that > would make the mix denser, less dense, etc. to suite our needs. We also > may > want to consider some of Ennimoser's ideas and make our base out of > carbon-based materials. Ennimoser claims that since were carbon-based > beings, the sonic signature of carbon-based structures sound the most > pleasant to our ears. I agree with him wholeheartedly. The reasoning is > that we will never be able to completely eliminate the sonic signature of > the base, so we should strive to: 1) Minimize it, and 2) Make the > residual signature as benign as possible. MDF is a carbon-based product > which is probably one reason why it finds so many applications in audio. > Adding carbon to our concrete mixes would also be very effective. I > finish > all of my components with shellac, which is made from the shells of the > lac > bug, as carbon-based as you can get. Tung oil is also a good carbon-based > finish. Polyurethane shouldn't sound as good (have you ever heard of a > polyurethane-finished violin?) although I'll agree with Thom that it > resists > cat pee better. The pedestal for my amplifier is a rough commercial > concrete column that I finished with a hand-rubbed shellac finish; it > looks > dynamite. I wouldn't mind having a carbon-filled concrete TT deck with a > hand-rubbed shellac finish. Just some thoughts. > > Ken > > Ken Schei, P.E. > Project Engineer > Antarctic Support Associates > Email address: scheike@asa.org > Phone: 303-643-0163 Subject: RE: [teres] Teres: Subchassis & Armboard Date: Wed, 16 Feb 2000 10:16:58 -0700 From: Schei, Kenneth, Schei, Kenneth To: 'teres@aiko.com' Even though the bones are damped by ligaments, etc. their fundamental resonant tone remains the same; it's only attenuated. That's why the test of rapping on the bone behind your ear is valid. When I check a speaker enclosure, I rap on the bone behind my ear and then rap on the speaker enclosure. Really good speakers generally sound closer to "bone" than do poor speakers. I agree with Grant, and that's part of my premise. The body does tend to mask "bone-like" sounds, and what doesn't get masked remains a warm, friendly, benign sound that is more pleasant to live with than most of the harsh distortions we have to cope with. Ken Ken Schei, P.E. Project Engineer Antarctic Support Associates Email address: scheike@asa.org Phone: 303-643-0163 > -----Original Message----- > From: Kalman Rubinson [SMTP:kr4@is2.nyu.edu] > Sent: Wednesday, February 16, 2000 7:53 AM > To: 'teres@aiko.com' > Subject: RE: [teres] Teres: Subchassis & Armboard > > On Wed, 16 Feb 2000, Sellek, Grant (TSA) wrote: > > > Ivan, I believe Ennemoser was most keenly interested in the resonant > > qualities of the human ear, so he focused on the "sound of human bone", > not > > so much on the average elemental proportions of the human body. He > theorised > > that the human brain must mask the innate sonic qualities of the > mechanisms > > of the human ear, otherwise everything would sound like buzzing bones, > so if > > the instrument's material and construction (he manufactures violins that > are > > very nonconformist but highly regarded) has a sonic signature similar to > > that of the internal human ear, then the brain will mask it out. > > This is silly. The bones are damped by their ligaments and > dynamically controlled by muscle action. Besides, the > dimensions of the bones involved are so small that any > resonances are very(!) high. > > > I have some sympathy with the central idea. And I think the whole notion > is > > even more crucial in audio than in musical instruments. > > I have no sympathy for the idea. Is there anything > experimental to support it? Are there prosthetic bones > with differing resonant characteristics which are less well > adapted? > > I think you'll find that the adaptive mechanisms of the > human brain are so capable (and pervasive) that this > cannot be relevant. > > Kal Subject: RE: [teres] Carbon based materials Date: Wed, 16 Feb 2000 10:18:33 -0700 From: Kalman Rubinson, Kalman Rubinson To: 'teres@aiko.com' On Wed, 16 Feb 2000, Schei, Kenneth wrote: > See my reply to Ivan where I clarified myself. To sum up, no, plastics > aren't right, and au contraire, adding carbon to concrete mix and finishing > the casting with shellac is indeed implimenting Ennemoser's philosophies. > You don't have to embrace them or even agree, but try considering the full > reasoning behind Ennemoser's and my ideas before you dismiss them. Is there any evidence aside from his postulates? Kal Subject: RE: [teres] Teres: Subchassis & Armboard Date: Wed, 16 Feb 2000 10:27:53 -0700 From: Kalman Rubinson, Kalman Rubinson To: 'teres@aiko.com' On Wed, 16 Feb 2000, Schei, Kenneth wrote: > Even though the bones are damped by ligaments, etc. their fundamental > resonant tone remains the same; it's only attenuated. That's why the test > of rapping on the bone behind your ear is valid. When I check a speaker > enclosure, I rap on the bone behind my ear and then rap on the speaker > enclosure. Really good speakers generally sound closer to "bone" than do > poor speakers. I agree with Grant, and that's part of my premise. The body > does tend to mask "bone-like" sounds, and what doesn't get masked remains a > warm, friendly, benign sound that is more pleasant to live with than most of > the harsh distortions we have to cope with. I only see a 'premise.' You use the premise but I see no compelling reason behind it. Kal Subject: Re: [teres] Teres-Motor&Supply Date: Wed, 16 Feb 2000 11:07:48 -0700 From: Steve Zettel, Steve Zettel To: teres@aiko.com on 2/16/00 07:33, Schei, Kenneth at SCHEIKE@asa.org wrote: > Manfred: > > 6V for 33 rpm makes sense. Maxon's 180 rpm/V is the no-load speed-voltage > ratio. That can be confirmed by dividing the maximum no-load speed by the > maximum rated voltage: 6450 rpm / 36V = 179.17 rpm/V. I like the 110189 as > a choice for our application. > > Ken I would second Ken's always considered and well-thought out analysis. BTW, though I was taking more of an active role in the bearing/platter design, and Ken and I were "nominated" as the leads in the motor/controller phase, I am more than content to take a big step back and admire Manfred's and the rest of the "heavy hitters'" expertise. Bravo! Perhaps I will have more to contribute to subchassis design, though that seems to be highly personal. One damped layer of Corian (tm) or two layers with damping constrained between comes to mind. A cheap source of slabs of this somewhat pricy stuff is the cutouts made for sinks in countertops. Even my local counter and cabinet shop in little Libby, MT has several on hand for next to nothing. Steve Subject: Re: [teres] Teres-Motor&Supply Date: Wed, 16 Feb 2000 11:19:29 -0700 From: Kalman Rubinson, Kalman Rubinson To: teres@aiko.com On Wed, 16 Feb 2000, Steve Zettel wrote: > Perhaps I will have more to contribute to subchassis design, though that > seems to be highly personal. One damped layer of Corian (tm) or two layers > with damping constrained between comes to mind. A cheap source of slabs of > this somewhat pricy stuff is the cutouts made for sinks in countertops. Even > my local counter and cabinet shop in little Libby, MT has several on hand > for next to nothing. Laminates of Corian and Dynamat are nicely 'dead.' Kal Subject: RE: [teres] Carbon based materials Date: Wed, 16 Feb 2000 11:23:10 -0700 From: Schei, Kenneth, Schei, Kenneth To: 'teres@aiko.com' What kind of evidence did you have in mind? Ken > -----Original Message----- > From: Kalman Rubinson [SMTP:kr4@is2.nyu.edu] > Sent: Wednesday, February 16, 2000 9:17 AM > To: 'teres@aiko.com' > Subject: RE: [teres] Carbon based materials > > On Wed, 16 Feb 2000, Schei, Kenneth wrote: > > > See my reply to Ivan where I clarified myself. To sum up, no, plastics > > aren't right, and au contraire, adding carbon to concrete mix and > finishing > > the casting with shellac is indeed implimenting Ennemoser's > philosophies. > > You don't have to embrace them or even agree, but try considering the > full > > reasoning behind Ennemoser's and my ideas before you dismiss them. > > Is there any evidence aside from his postulates? > > Kal Subject: Re: [teres] Teres-Motor&Supply Date: Wed, 16 Feb 2000 11:39:24 -0700 From: Steve Zettel, Steve Zettel To: teres@aiko.com on 2/16/00 10:17, Kalman Rubinson at kr4@is2.nyu.edu wrote: > On Wed, 16 Feb 2000, Steve Zettel wrote: > >> Perhaps I will have more to contribute to subchassis design, though that >> seems to be highly personal. One damped layer of Corian (tm) or two layers >> with damping constrained between comes to mind. A cheap source of slabs of >> this somewhat pricy stuff is the cutouts made for sinks in countertops. Even >> my local counter and cabinet shop in little Libby, MT has several on hand >> for next to nothing. > > Laminates of Corian and Dynamat are nicely 'dead.' > > Kal My thoughts exactly, Kal. Both are readily available, relatively inexpensive, and easily worked. I have been using a slab of Corian under my (suspended) Oracle for several years and like it better than the MDF, particle board, hardwood, carpeted particle board or flagstone shelfs I have tried at various times in the past. Steve Z near Libby, MT Subject: RE: [teres] Carbon based materials Date: Wed, 16 Feb 2000 11:55:06 -0700 From: Kalman Rubinson, Kalman Rubinson To: 'teres@aiko.com' On Wed, 16 Feb 2000, Schei, Kenneth wrote: > What kind of evidence did you have in mind? Any psychoacoustic experiments which indicate that the resonant properties mentioned have any relation to specific adaptive neural mechanisms. Kal Subject: RE: [teres] Carbon based materials Date: Wed, 16 Feb 2000 12:08:51 -0700 From: Schei, Kenneth, Schei, Kenneth To: 'teres@aiko.com' Kal: Do "subjective" listening experiences count as evidence? Ken Ken Schei, P.E. Project Engineer Antarctic Support Associates Email address: scheike@asa.org Phone: 303-643-0163 > -----Original Message----- > From: Kalman Rubinson [SMTP:kr4@is2.nyu.edu] > Sent: Wednesday, February 16, 2000 10:54 AM > To: 'teres@aiko.com' > Subject: RE: [teres] Carbon based materials > > On Wed, 16 Feb 2000, Schei, Kenneth wrote: > > > What kind of evidence did you have in mind? > > Any psychoacoustic experiments which indicate that > the resonant properties mentioned have any relation > to specific adaptive neural mechanisms. > > Kal Subject: RE: [teres] Carbon based materials Date: Wed, 16 Feb 2000 12:10:29 -0700 From: Schei, Kenneth, Schei, Kenneth To: 'teres@aiko.com' Do "subjective" listening experiences count as evidence? Ken Ken Schei, P.E. Project Engineer Antarctic Support Associates Email address: scheike@asa.org Phone: 303-643-0163 > -----Original Message----- > From: Kalman Rubinson [SMTP:kr4@is2.nyu.edu] > Sent: Wednesday, February 16, 2000 10:54 AM > To: 'teres@aiko.com' > Subject: RE: [teres] Carbon based materials > > On Wed, 16 Feb 2000, Schei, Kenneth wrote: > > > What kind of evidence did you have in mind? > > Any psychoacoustic experiments which indicate that > the resonant properties mentioned have any relation > to specific adaptive neural mechanisms. > > Kal Subject: Re: [teres] Teres-Motor&Supply Date: Wed, 16 Feb 2000 12:11:17 -0700 From: Kalman Rubinson, Kalman Rubinson To: teres@aiko.com On Wed, 16 Feb 2000, Steve Zettel wrote: > Both are readily available, relatively inexpensive, and easily worked. I > have been using a slab of Corian under my (suspended) Oracle for several > years and like it better than the MDF, particle board, hardwood, carpeted > particle board or flagstone shelfs I have tried at various times in the > past. I am not building a Teres and I'm here for the exchange of info. I am finishing a TT with a Corian/Dynamat/Lead/Aluminum plinth and I've fiddled with Corian for a while. It has a distinctive 'ring' by itself but is easily damped. Kal Subject: RE: [teres] Carbon based materials Date: Wed, 16 Feb 2000 12:17:43 -0700 From: Kalman Rubinson, Kalman Rubinson To: 'teres@aiko.com' On Wed, 16 Feb 2000, Schei, Kenneth wrote: > Kal: > > Do "subjective" listening experiences count as evidence? No. Evidence of what? They do not prove the premise even if they are valid and reproducible. Kal Subject: RE: [teres] Carbon based materials Date: Wed, 16 Feb 2000 13:11:36 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: 'teres@aiko.com' Oh, heck, there's nothing that can't be solved by the frivolous waste of money copiously thrown at a problem. Just buy a large Diamond Racing Platform, drill & trim the thing down, diamond stud the perimeter, and voila ! A subchassis you can *really* brag about! (Just sniping from the sidelines) Igor :-) --- Kalman Rubinson wrote: > On Wed, 16 Feb 2000, Schei, Kenneth wrote: > > > Kal: > > > > Do "subjective" listening experiences count as > evidence? > > No. Evidence of what? They do not prove the premise > even if > they are valid and reproducible. > > Kal > > __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com Subject: RE: [teres] Teres: Subchassis & Armboard Date: Wed, 16 Feb 2000 14:48:45 -0700 From: Mikhail Karlin, Mikhail Karlin To: 'teres@aiko.com' I'll try my take on it: there two different sounds are heard- one through outer ear by air conduction and one through vibrations of the scull by bone conduction, both get to inner ear, auditory nerve... Try listening to the sound of your own recorded voice - it'llsound unnatural to you because the microphone receives only the airborne sound but your ear's used to hearing both signals airborne and bone transmitted If what Ken describes in his post help somehow to "make up" for the lost info at the recording, adding the tonality that ear missing... Just an attempt to make sense to myself Michael On Wed, 16 Feb 2000, Kalman Rubinson wrote: > On Wed, 16 Feb 2000, Schei, Kenneth wrote: > > Even though the bones are damped by ligaments, etc. their fundamental > > resonant tone remains the same; it's only attenuated. That's why the test > > of rapping on the bone behind your ear is valid. When I check a speaker > > enclosure, I rap on the bone behind my ear and then rap on the speaker > > enclosure. Really good speakers generally sound closer to "bone" than do > > poor speakers. I agree with Grant, and that's part of my premise. The body > > does tend to mask "bone-like" sounds, and what doesn't get masked remains a > > warm, friendly, benign sound that is more pleasant to live with than most of > > the harsh distortions we have to cope with. > > I only see a 'premise.' You use the premise but I see no > compelling reason behind it. > > Kal > Subject: RE: [teres] Carbon based materials Date: Wed, 16 Feb 2000 15:14:01 -0700 From: Schei, Kenneth, Schei, Kenneth To: 'teres@aiko.com' Kal: An interesting position, which I respect, but which seems to point toward the classic "objectivist" vs "subjectivist" debate which has been endlessly chronicled elsewhere. I have no desire to enter into that debate, even though I have many opinions about it. Audio is a hobby for me; my objectives are to reproduce music well and have fun doing so. Thus I am results oriented. I like to share my ideas with others and to benefit from their ideas, but I have no desire to try to "prove" anything, whatever that means. I do find it interesting that those of us who prefer analog and ancient vacuum tubes would find it a lot harder to defend our positions if we couldn't point to listening experiences that we think are superior. Ken Ken Schei, P.E. Project Engineer Antarctic Support Associates Email address: scheike@asa.org Phone: 303-643-0163 > -----Original Message----- > From: Kalman Rubinson [SMTP:kr4@is2.nyu.edu] > Sent: Wednesday, February 16, 2000 11:17 AM > To: 'teres@aiko.com' > Subject: RE: [teres] Carbon based materials > > > > On Wed, 16 Feb 2000, Schei, Kenneth wrote: > > > Kal: > > > > Do "subjective" listening experiences count as evidence? > > No. Evidence of what? They do not prove the premise even if > they are valid and reproducible. > > Kal Subject: Re: [teres] Teres-Motor&Supply Date: Wed, 16 Feb 2000 16:59:51 -0700 From: David Suess, David Suess To: teres@aiko.com Steve Zettel says: > Perhaps I will have more to contribute to subchassis design, though that > seems to be highly personal. One damped layer of Corian (tm) or two layers > with damping constrained between comes to mind. A cheap source of slabs of > this somewhat pricy stuff is the cutouts made for sinks in countertops. Even > my local counter and cabinet shop in little Libby, MT has several on hand > for next to nothing. I have just such a piece of Corian that I rescued from the garage of my sister-in-law. t's the cutout piece from a double sink and is more than ample size. I also pieces of matching backsplash material that will great for making an armboard for my RB300. I'm planning to put the Corian on top of several layers of MDF/and/or/plywood for my Teres base. - david Subject: RE: [teres] Teres: Subchassis & Armboard Date: Wed, 16 Feb 2000 17:11:20 -0700 From: Kalman Rubinson, Kalman Rubinson To: 'teres@aiko.com' On Wed, 16 Feb 2000, Mikhail Karlin wrote: > I'll try my take on it: there two different sounds are heard- one > through outer ear by air conduction and one through vibrations of the > scull by bone conduction, both get to inner ear, auditory nerve... > Try listening to the sound of your own recorded voice - it'llsound > unnatural to you because the microphone receives only the airborne sound > but your ear's used to hearing both signals airborne and bone transmitted So. Both perceptions are real and accurate. > If what Ken describes in his post help somehow to "make up" for the lost > info at the recording, adding the tonality that ear missing... > Just an attempt to make sense to myself What's missing? Bone conduction for the music? Kal Subject: RE: [teres] Carbon based materials Date: Wed, 16 Feb 2000 17:16:02 -0700 From: Kalman Rubinson, Kalman Rubinson To: 'teres@aiko.com' On Wed, 16 Feb 2000, Schei, Kenneth wrote: > An interesting position, which I respect, but which seems to point toward > the classic "objectivist" vs "subjectivist" debate which has been endlessly > chronicled elsewhere. I have no desire to enter into that debate, even > though I have many opinions about it. Audio is a hobby for me; my > objectives are to reproduce music well and have fun doing so. Thus I am > results oriented. I like to share my ideas with others and to benefit from > their ideas, but I have no desire to try to "prove" anything, whatever that > means. I do find it interesting that those of us who prefer analog and > ancient vacuum tubes would find it a lot harder to defend our positions if > we couldn't point to listening experiences that we think are superior. I am not objecting to your position nor do I suggest that listening assessment is unreliable or irrelevant. I am content to experience an improvement in sound and accept it. I would like an explanation but it often cannot be found. However, if an explanation is offered, it should be supported by evidence. Here's the common logical failing of pseudoexplanations so rife in audio: Someone posits that, because of C, A will sound better than B. So, we do a listening test and, indeed, A sounds better than B. However, it does not prove anything about C or its relation to A. Kal Subject: RE: [teres] Teres-Motor&Supply Date: Thu, 17 Feb 2000 09:36:18 -0700 From: Moy, William [AMSTA-AR-CCL-D], Moy, William [AMSTA-AR-CCL-D] To: 'teres@aiko.com' CC: Moy, William [AMSTA-AR-CCL-D] Hi Chris, Is that possible this kit includes a heavy steel cage/shield for the drive motor and how much would it cost? Thanks Bill Moy -----Original Message----- From: Chris Brady [mailto:cbrady@sgi.com] Sent: Monday, February 14, 2000 5:00 PM To: teres@aiko.com; mikeinchandler@home.com; audiodir@gte.net; MHuber@t-online.de Subject: [teres] Teres-Motor&Supply I am really jazzed about using Manfreds excellent controller design with the Teres so I have been digging up some info. I called the US Maxxon rep and got prices for the 110189 motor: 1-4 $83.45 5-19 $66.25 20-49 $57.80 These prices seem reasonable, especially if we do a group purchase. I a have faxed copy of the spec's for this motor and it looks like an excellent choice. I also have a catalogue on it's way so that other choices from Maxxon can be considered. Perhaps I can scan some of the relevant pages and put them on the web page. I confirmed that the $29 programmer kit works with the at89c2051 so we have an inexpensive way to program the chips here in the US. I also downloaded and experimented with the free C compiler that Manfred pointed me to. I have the C code ported and I am working on porting the assembler. It looks like the free compiler will be suitable, but the documentation is poor. If there is enough interest I would be willing to put together motor/controller kits for the group. I envision that the kit would include: - A Maxxon 110189 motor - A precision machined pulley (from Bryce) - A printed circuit board (from Ron Wellborn) - A pre-programmed at89c2051 (code supplied by Manfred, programed by me) - All of the other electronic parts (caps, IC's resistors, etc) - Basic instructions - An AC transformer By doing a group purchase we would save big time on the pulley and circuit boards. There would also be a savings of 10-15% for the other components if we are doing 20+ kits. This would also help with the shipping costs and minimum order problems when you have to source parts from 4 - 5 different vendors. I am generous but not crazy so I would expect to make a little on each kit to cover some of my time investment. But even with my charge the kit price would be less than the cost of doing an individual purchase. I also feel that Manfred should receive some compensation for his generous sharing of the controller design. Perhaps some extra circuit boards? How many would be interested? Comments? Chris Subject: RE: [teres] Teres-Motor&Supply Date: Thu, 17 Feb 2000 10:05:59 -0700 From: Mackris, Thom G., Mackris, Thom G. To: 'teres@aiko.com' Hi Bill, Chris is out of town on business today (Thursday) through tomorrow (Friday), so let me take a first crack responding to your request to consider including some form of steel shielding or housing for the motor. If you're talking about some kind of "can" to slip over the motor, then perhaps mu-metal is the solution you're looking for. Additional good good news comes from the fact that we're using a DC motor so other than some of the garbage resulting from the brushes, the motor will be fairly quiet from an electrical noise standpoint. At the end of this reply, I'm attaching a thread I compiled from last year from the Joe list on sourcing mu-metal. Note the comments about thin guage and easy conformability. Since we're likely to diverge in our concepts of motor housing / subchassis, this is important - one size does not necessarily fit all solutions. My current two thoughts for housing/mounting the motor are (a) Something resembling the preliminary drawing that Chris put up on his website and (b) a cylinder made of PVC tubing - finished with Hammerite or some other tough/glossy finish. Chris' option looks to be a bit more flexible as it affords the opportunity for more mass loading, as well as a housing for the controller board. Cheers, Thom -------------------------------------- Compiled thread follows .... -------------------------------------- Hi all - >From Joe_List (#313 & #369), John Leverault noted that our favorite bad-boy, Corey Greenberg discussed some hum busting techniques for Grado Cartridges and Rega 'tables in this July's Audio Magazine (p22-25) of all places. He uses a Mu-Metal kit from: Magnetic Shield Corporation (630) 766-7800 ... product # LK-110 Hum and (unshielded) Grados has traditionally been a problem with the AR turntables which I had highly recommended to Chris (BTW, no hum problems in my friends' with a Shure cartridge). This would be great if you could mate these two products without a hum problem. and ... from Joe_List vol 369 (7/31/98) .. Date: Fri, 31 Jul 1998 16:01:03 +1000 From: "Ian McPhail" Subject: mu metal hum job Anyone seen the interesting article in July 98 issue of Audio by Corey Greenberg hum busting a Grado (unshielded) on a Rega Planar 3 (unshielded motor). He mentions a try out kit of mu metal sample pieces avalable from Magnetic Shield Corporation for $80. http:://magnetic-shield.com/labkit.html regards Ian Ian McPhail i.mcphail@rmit.edu.au RMIT Chem and Met Eng Dept 110 GPO Box 2476V Melbourne 3001 Australia tel +61 3 9925 2408 fax +61 3 9925 3746 ------------------------------ Date: Fri, 31 Jul 1998 02:16:08 EDT From: Acrosound@aol.com Subject: Re: mu metal hum job In a message dated 7/31/98 1:05:57 AM, Ian wrote: >Anyone seen the interesting article in July 98 issue of Audio by Corey >Greenberg hum busting a Grado (unshielded) on a Rega Planar 3 (unshielded >motor). He mentions a try out kit of mu metal sample pieces avalable from >Magnetic Shield Corporation for $80. >http:://magnetic-shield.com/labkit.html If anyone needs little pieces of mu-metal for experimentation drop me an email. I have some .006" thick material. If ya just need just a little....it probably would be free... if I need to mail it to australia (sorry Ian dude) it probably won't be free :=). Mikey Date: Sat, 1 Aug 1998 22:46:40 -0400 From: Bruce Kinch Subject: Re: mu metal hum job > There is a product available from electrosonic (www.electrosonic.com) >that is a spray on version of a RFI/EMI blocker. I think it costs >$35.95CAN. I might be worth investigating for people with hum problems. >If there is any interest in this product I can post more details. > Bruce Kinch in 'Primyl Vinyl' vol.3 no.3 also says that this stuff from >Magnetic Shield Corp. is available for their $50.00 minimum order and this >will get you enough to do two Rega 3's or enough for one and maybe do your >preamp. > The Magnetic Shield hum-fix described in Primyl Vinyl Vol 3 #3 is a .04" metal Co-Netic AA "foil" (i.e. easily bent to shape as needed). It is available in 15"w by any length, with an adhesive back at extra cost. You can wrap it around the motor housing or simply lay/stick it on the plinth under the platter with holes cut for the bearing and motor shaft. Magnetic Shield is in Bensonville, IL, USA, at www.magnetic-shield.com, tel 630-766-7800, fax 630-766-2813. Bruce C. Kinch Editor Primyl Vinyl The Audiophile Record Collectors Newsletter -------------------------------------- End -Compiled thread -------------------------------------- -----Original Message----- From: Moy, William [AMSTA-AR-CCL-D] [mailto:wtmoy@pica.army.mil] Sent: Thursday, February 17, 2000 8:36 AM To: 'teres@aiko.com' Cc: Moy, William [AMSTA-AR-CCL-D] Subject: RE: [teres] Teres-Motor&Supply Hi Chris, Is that possible this kit includes a heavy steel cage/shield for the drive motor and how much would it cost? Thanks Bill Moy Subject: RE: [teres] Teres-Motor&Supply Date: Thu, 17 Feb 2000 11:29:33 -0700 From: Mackris, Thom G., Mackris, Thom G. To: 'teres@aiko.com' Ron, Lead and other mass loading/damping seems like a fine idea to me. Would solid lead be better than say a mix of lead shot & sand? Comments from our damping experts?? Something like the box in Chris' preliminary drawing would certainly afford a lot of volume to (a) load up with mass and (b) house the controller. I'll bet we could get that pod to weigh 15 lbs. (that's 7 kilos to the rest of you folks) without tring too hard. BTW, a co-worker I knew in California was a skeet shooter (clay pidgeons - shotgun). He told me that skeet ranges sell recycled lead shot at about 50% off the normal retail price. I have not verified this. Thom -----Original Message----- From: Ron Welborne [mailto:wlabs@ix.netcom.com] Sent: Thursday, February 17, 2000 10:12 AM To: teres@aiko.com Subject: Re: [teres] Teres-Motor&Supply Possibly one of my last suggestions ended up in the 'domo bit bucket. Here goes again: The motor should be mounted in/on a very heavy mass to help isolate from vibrations. I previously suggested a housing or base manufactured from lead. It seems that a simple mold could be easily created and then poured by ourselves. Lead is soft thereby making it easy to work with. A lead cup, or square box, with the motor mounted to the lid is one possible option. A cylindrical lead base fitted with a PVC cover might be another option. Any thoughts out there on using lead? Ron Welborne Labs wlabs@ix.netcom.com ph: 303.470.6585 fax: 303.791.5783 website --------------- www.welbornelabs.com ----------------- ----- Original Message ----- From: Mackris, Thom G. To: Sent: Thursday, February 17, 2000 8:52 AM Subject: RE: [teres] Teres-Motor&Supply > Hi Bill, > > Chris is out of town on business today (Thursday) through tomorrow (Friday), > so let me take a first crack responding to your request to consider > including some form of steel shielding or housing for the motor. > > If you're talking about some kind of "can" to slip over the motor, then > perhaps mu-metal is the solution you're looking for. Additional good good > news comes from the fact that we're using a DC motor so other than some of > the garbage resulting from the brushes, the motor will be fairly quiet from > an electrical noise standpoint. > > At the end of this reply, I'm attaching a thread I compiled from last year > from the Joe list on sourcing mu-metal. Note the comments about thin guage > and easy conformability. Since we're likely to diverge in our concepts of > motor housing / subchassis, this is important - one size does not > necessarily fit all solutions. > > My current two thoughts for housing/mounting the motor are (a) Something > resembling the preliminary drawing that Chris put up on his website and (b) > a cylinder made of PVC tubing - finished with Hammerite or some other > tough/glossy finish. Chris' option looks to be a bit more flexible as it > affords the opportunity for more mass loading, as well as a housing for the > controller board. > > Cheers, > Thom > > -------------------------------------- > Compiled thread follows .... > -------------------------------------- > > > Hi all - > > From Joe_List (#313 & #369), John Leverault noted that our > favorite bad-boy, Corey Greenberg discussed some hum busting techniques for > Grado Cartridges and Rega 'tables in this July's Audio Magazine (p22-25) of > all places. > > He uses a Mu-Metal kit from: > > Magnetic Shield Corporation (630) 766-7800 ... product # LK-110 > > Hum and (unshielded) Grados has traditionally been a problem with the AR > turntables which I had highly recommended to Chris (BTW, no hum problems in > my friends' with a Shure cartridge). This would be great if you could mate > these two products without a hum problem. > > and ... from Joe_List vol 369 (7/31/98) .. > > > Date: Fri, 31 Jul 1998 16:01:03 +1000 > From: "Ian McPhail" > Subject: mu metal hum job > > Anyone seen the interesting article in July 98 issue of Audio by Corey > Greenberg hum busting a Grado (unshielded) on a Rega Planar 3 (unshielded > motor). He mentions a try out kit of mu metal sample pieces avalable from > Magnetic Shield Corporation for $80. > http:://magnetic-shield.com/labkit.html > regards Ian > > Ian McPhail i.mcphail@rmit.edu.au > RMIT Chem and Met Eng Dept 110 > GPO Box 2476V > Melbourne 3001 > Australia > tel +61 3 9925 2408 > fax +61 3 9925 3746 > > ------------------------------ > > Date: Fri, 31 Jul 1998 02:16:08 EDT > From: Acrosound@aol.com > Subject: Re: mu metal hum job > > In a message dated 7/31/98 1:05:57 AM, Ian wrote: > > >Anyone seen the interesting article in July 98 issue of Audio by Corey > >Greenberg hum busting a Grado (unshielded) on a Rega Planar 3 (unshielded > >motor). He mentions a try out kit of mu metal sample pieces avalable from > >Magnetic Shield Corporation for $80. > >http:://magnetic-shield.com/labkit.html > > > If anyone needs little pieces of mu-metal for experimentation drop me an > email. I have some .006" thick material. If ya just need just a > little....it > probably would be free... > > if I need to mail it to australia (sorry Ian dude) it probably won't be free > :=). > > Mikey > > > Date: Sat, 1 Aug 1998 22:46:40 -0400 > From: Bruce Kinch > Subject: Re: mu metal hum job > > > There is a product available from electrosonic (www.electrosonic.com) > >that is a spray on version of a RFI/EMI blocker. I think it costs > >$35.95CAN. I might be worth investigating for people with hum problems. > >If there is any interest in this product I can post more details. > > Bruce Kinch in 'Primyl Vinyl' vol.3 no.3 also says that this stuff from > >Magnetic Shield Corp. is available for their $50.00 minimum order and this > >will get you enough to do two Rega 3's or enough for one and maybe do your > >preamp. > > > > The Magnetic Shield hum-fix described in Primyl Vinyl Vol 3 #3 is a .04" > metal Co-Netic AA "foil" (i.e. easily bent to shape as needed). It is > available in 15"w by any length, with an adhesive back at extra cost. > > You can wrap it around the motor housing or simply lay/stick it on the > plinth under the platter with holes cut for the bearing and motor shaft. > > Magnetic Shield is in Bensonville, IL, USA, at www.magnetic-shield.com, tel > 630-766-7800, fax 630-766-2813. > > > Bruce C. Kinch > Editor > Primyl Vinyl > The Audiophile Record Collectors Newsletter > > -------------------------------------- > End -Compiled thread > -------------------------------------- > > -----Original Message----- > From: Moy, William [AMSTA-AR-CCL-D] [mailto:wtmoy@pica.army.mil] > Sent: Thursday, February 17, 2000 8:36 AM > To: 'teres@aiko.com' > Cc: Moy, William [AMSTA-AR-CCL-D] > Subject: RE: [teres] Teres-Motor&Supply > > > Hi Chris, > > Is that possible this kit includes a heavy steel cage/shield for the drive > motor and how much would it cost? > Thanks > > Bill Moy Subject: RE: [teres] Teres-Motor&Supply Date: Thu, 17 Feb 2000 13:05:34 -0700 From: Kalman Rubinson, Kalman Rubinson To: 'teres@aiko.com' On Thu, 17 Feb 2000, Mackris, Thom G. wrote: > Lead and other mass loading/damping seems like a fine idea to me. Would > solid lead be better than say a mix of lead shot & sand? Comments from our > damping experts?? We used a PVC cylinder with the base filled with lead shot, lined with mu-metal and topped with a Corian laminate. Kal Subject: RE: [teres] Teres-Motor&Supply/Shield&Damping Date: Thu, 17 Feb 2000 15:02:46 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com Ron, Mass loading the motor pod was discussed some time ago, early in the project. It is a fine idea, and should certainly be done. Lead by itself would probably be too dimensionally unstable to form a housing out of, and, of course, the motor could not be mounted directly to it. But, using it to form a housing, as per your suggestion is a still a good idea. It would be more practical to find an attractive metal housing of the right size, with a convenient wall thickness, and use it *as* the non-detachable mold & outer cosmetic. What I mean is pour the lead right into it, and leave it attached. A second (smaller, of course) container or sleeve of metal, say easily formable copper, which would also serve as a (partial) shield (or use mu-metal,as suggested below) could be used to make the inner form/wall, and the lead poured between them, leaving the inside hollow. Doing it this way is simpler *and* more effective, *both*. This would result in a top of stiffer metal, sides shielded/ reinforced/damped/mass loaded, and bottom, depending on how you orient & arrange the parts. Additional shielding could easily be added to the (thin, possibly only decorative in terms of shielding) top by laminating a shielding layer of your choice. Mu-metal is indeed the material of choice, but pricey, I noticed, from looking at several catalogs that I have, some time ago. Copper is, while also not exactly cheap (but we only need a little), easily obtainable, and cheaper than mu-metal. It can be obtained from roofing supply houses in a fairly respectably thick gauge. They use it for flashing & other roofing work. Also for trim & fancy range hoods occasionally in "designer" kitchens. Copper can also be obtained from hobby supply shops in small sheets, and from Dick Blick's Art Supply. Chances are, if you call a roofer or three, you can obtain cutoffs for next to nothing, if that. Please keep in mind that while copper is very good with RFI, it is not as good with EMI, and that is what the motor is likely to put out, even our DC motor, as Ken pointed out earlier. Steel can actually be a better shield for EMI than copper, making it a likely choice for the box, unless you can find a monel metal box of suitable size. Interestingly, while monel is expensive now, back during the '50's or so a lot of restaurant counters & containers were made of monel because it has rust & corrosion resistance properties akin to that of stainless steel. If you have some idea of how to find some of that... The most practical combo of choice would be to use copper sheet for the inside wall form, and a sheet of mu-metal laminated to the underside of the top. This would keep the top thin but effective, and the thick sidewalls of copper/lead/whatever metal the box is made of should be plenty effective as well. Whatever space is left under the motor can be filled with, you guessed it, sand/whatever, if you like, but I would suggest stabilizing its location somehow by "skinning" its surface with whatever is handy that's rubbery & flexible, so that it cannot get into, or even onto, the motor. Or just go with all lead, so long as you are working with it anyway. The addition of sand would probably be superior to depending on just the lead, as sand has good acoustic damping properties that are different from lead, but this would represent some additional fuss. If you do use a sand mix, I suggest mixing in recycled tire rubber chips before the addition of lead shot, which is also a good addition, but secondary to the rubber chips. Sorry, don't have time to rehash the virtues of rubber chips, we beat that subject to death already earlier in the project, please look up the old posts. It might be a good idea to drill a few air holes for cooling, but I do not know if these motors require that under the loads we will subject them to. Perhaps our motor experts will supply that datum. Finally, please keep in mind that this is *not* (by *any* crippling of the imagination) an AR. The AR used an AC motor, and that was placed under the platter. We are (most of us) using a DC motor, and it will be placed away from the playing area the cartridge will be traversing. Even if the motor is placed on the non-traditional right side, something that made Ken nervous the other day. Even if on the right side, when the cartridge is in play, the arm with cart & wiring are *moved away* from the general location of the motor, which, obviously, should not be placed any closer to the sensitive parts than can be helped. a matter of choice & careful implementation. A little shielding to be sure, and we should good. Igor --- "Mackris, Thom G." wrote: > Ron, > > Lead and other mass loading/damping seems like a > fine idea to me. Would > solid lead be better than say a mix of lead shot & > sand? Comments from our > damping experts?? > > Something like the box in Chris' preliminary drawing > would certainly afford > a lot of volume to (a) load up with mass and (b) > house the controller. I'll > bet we could get that pod to weigh 15 lbs. (that's 7 > kilos to the rest of > you folks) without tring too hard. > > BTW, a co-worker I knew in California was a skeet > shooter (clay pidgeons - > shotgun). He told me that skeet ranges sell > recycled lead shot at about 50% > off the normal retail price. I have not verified > this. > > Thom > > -----Original Message----- > From: Ron Welborne [mailto:wlabs@ix.netcom.com] > Sent: Thursday, February 17, 2000 10:12 AM > To: teres@aiko.com > Subject: Re: [teres] Teres-Motor&Supply > > > > Possibly one of my last suggestions ended up in the > 'domo bit bucket. Here > goes again: > > The motor should be mounted in/on a very heavy mass > to help isolate from > vibrations. I previously suggested a housing or > base manufactured from > lead. It seems that a simple mold could be easily > created and then poured > by ourselves. Lead is soft thereby making it easy > to work with. > > A lead cup, or square box, with the motor mounted to > the lid is one possible > option. > > A cylindrical lead base fitted with a PVC cover > might be another option. > > Any thoughts out there on using lead? > > > Ron > > Welborne Labs > wlabs@ix.netcom.com > ph: 303.470.6585 > fax: 303.791.5783 > website --------------- www.welbornelabs.com > ----------------- > > ----- Original Message ----- > From: Mackris, Thom G. > To: > Sent: Thursday, February 17, 2000 8:52 AM > Subject: RE: [teres] Teres-Motor&Supply > > > > Hi Bill, > > > > Chris is out of town on business today (Thursday) > through tomorrow > (Friday), > > so let me take a first crack responding to your > request to consider > > including some form of steel shielding or housing > for the motor. > > > > If you're talking about some kind of "can" to slip > over the motor, then > > perhaps mu-metal is the solution you're looking > for. Additional good good > > news comes from the fact that we're using a DC > motor so other than some of > > the garbage resulting from the brushes, the motor > will be fairly quiet > from > > an electrical noise standpoint. > > > > At the end of this reply, I'm attaching a thread I > compiled from last year > > from the Joe list on sourcing mu-metal. Note the > comments about thin > guage > > and easy conformability. Since we're likely to > diverge in our concepts of > > motor housing / subchassis, this is important - > one size does not > > necessarily fit all solutions. > > > > My current two thoughts for housing/mounting the > motor are (a) Something > > resembling the preliminary drawing that Chris put > up on his website and > (b) > > a cylinder made of PVC tubing - finished with > Hammerite or some other > > tough/glossy finish. Chris' option looks to be a > bit more flexible as it > > affords the opportunity for more mass loading, as > well as a housing for > the > > controller board. > > > > Cheers, > > Thom > > > > -------------------------------------- > > Compiled thread follows .... > > -------------------------------------- > > > > > > Hi all - > > > > From Joe_List (#313 & #369), John Leverault noted > that our > > favorite bad-boy, Corey Greenberg discussed some > hum busting techniques > for > > Grado Cartridges and Rega 'tables in this July's > Audio Magazine (p22-25) > of > > all places. > > > > He uses a Mu-Metal kit from: > > > > Magnetic Shield Corporation (630) 766-7800 ... > product # LK-110 > > > > Hum and (unshielded) Grados has traditionally been > a problem with the AR > > turntables which I had highly recommended to Chris > (BTW, no hum problems > in > > my friends' with a Shure cartridge). This would > be great if you could > mate > > these two products without a hum problem. > > > > and ... from Joe_List vol 369 (7/31/98) .. > > > > > > Date: Fri, 31 Jul 1998 16:01:03 +1000 > > From: "Ian McPhail" > > Subject: mu metal hum job > > > > Anyone seen the interesting article in July 98 > issue of Audio by Corey > > Greenberg hum busting a Grado (unshielded) on a > Rega Planar 3 (unshielded > > motor). He mentions a try out kit of mu metal > sample pieces avalable from > > Magnetic Shield Corporation for $80. > > http:://magnetic-shield.com/labkit.html > > regards Ian > > > > Ian McPhail i.mcphail@rmit.edu.au > > RMIT Chem and Met Eng Dept 110 > > GPO Box 2476V > > Melbourne 3001 > > Australia > > tel +61 3 9925 2408 > > fax +61 3 9925 3746 > > > > ------------------------------ > > > > Date: Fri, 31 Jul 1998 02:16:08 EDT > > From: Acrosound@aol.com > > Subject: Re: mu metal hum job > > > > In a message dated 7/31/98 1:05:57 AM, Ian wrote: > > > > >Anyone seen the interesting article in July 98 > issue of Audio by Corey > > >Greenberg hum busting a Grado (unshielded) on a > Rega Planar 3 (unshielded > > >motor). He mentions a try out kit of mu metal > sample pieces avalable from > > >Magnetic Shield Corporation for $80. > > >http:://magnetic-shield.com/labkit.html > > > > > > If anyone needs little pieces of mu-metal for > experimentation drop me an > > email. I have some .006" thick material. If ya > just need just a > > little....it > === message truncated === __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com Subject: [teres] Subchassis & Armboard Date: Thu, 17 Feb 2000 16:59:17 -0700 From: Mackris, Thom G., Mackris, Thom G. To: 'teres@aiko.com' All, If you hit the "back to reference library" button at the bottom of the page on the link Stanley sent us below, you get to Manufacturing Net Reference Library: http://www.mfg-net.com/reflib/default.asp?91,30 Lot's of interesting stuff on materials, lubrication technology, etc. Cheers, Thom -----Original Message----- From: Stanley Goudge [mailto:sgoudge@cisco.com] Sent: Thursday, February 17, 2000 12:59 PM Subject: Re: [teres] Teres-Motor&Supply [snip] http://www.mfg-net.com/reflib/tutorial4.asp Subject: RE: [teres] Teres-Motor&Supply/Shield&Damping Date: Thu, 17 Feb 2000 17:12:25 -0700 From: Scott Fraser, Scott Fraser To: teres@aiko.com Mass helps, but something lossy in combination with the mass makes the system perform much better. On our most critical optical components we use an old trick of filling a chamber in the housing not with lead, but with lead shot and then filling the space around that with light mineral oil. The dashpot action of oil on the shot is great at eliminating the motions that mass alone would leave behind.... Tested this on a Scheu and it is quiet. Scott = = = = = = = = = = = = = = = = = Scott Fraser (sefraser@caltech.edu) Caltech, Beckman Institute (139-74) Pasadena, CA 91125 626 395-2790 telephone 626 449-5163 fax Subject: [teres] tonearm length Date: Thu, 17 Feb 2000 20:33:03 -0700 From: Sellek, Grant (TSA), Sellek, Grant (TSA) To: 'Teres List' I saw an ultra-high-end turntable advertisement and it had an unusually long tonearm fitted. OTOH some equally high-end turntables have shortie arms. It seems there is no one optimal solution for arm length? What are the pros and cons of different length arms for our Tereses? It obviously affects the plinth design, so I would like to have this conversation now. Also, is it OK to mount the tonearm on a base that, rather like the motor base, just rests on the main plinth? I had assumed this was a no-no until I saw the exotic Japanese RS tonearm that Gordon Rankin once thought of distributing (but it fell through). This has a built-in base, not particularly massive, that has its own RCA plugs and simply stands on the armboard. Grant Sellek Adelaide, Australia grant.sellek@transport.sa.gov.au