Subject: Re: [teres] Bases and Vibration Date: Thu, 6 Apr 2000 18:55:55 -0700 From: MaughanAudio@aol.com, MaughanAudio@aol.com To: teres@aiko.com In a message dated 4/5/00 10:42:02 PM Mountain Daylight Time, cbrady@sgi.com writes: << I have hammered out some of the last details of my chassis design and will soon be making sawdust and some aluminum chips. I put together a web page with a description, drawings and some pictures. I would appreciate comments about and/or criticism of my design. >> Very impressive design! You have certainly created a work of art in form and function. It is evident that you have gleaned a lot of valuable insight into what will serve as an excellent chassis. My only suggestion would be to increase the thickness of the cantilevered arm support. Will the use of the thicker support improve the sound? I don't know if you'll hear it, but my caveat is that the VPI TNT has a serious flaw in it's arm design. The cantilevered arm support off the threaded VTA assembly was only about 1/4" aluminum which is not supportive enough, thus very audible sub 25 Hz rumble is present from feedback. You did think this out more then VPI and the composite structure is certainly much more substantial. Just something to consider because I know it is a critical design element. One of the most important aspects of your design, I believe, will give you superior performance over the norm is how you created a rigid bearing to armboard interface and then submerse that whole assembly in an energy sink. Excellent! Until Again, Gordon. Subject: Re: [teres] vibration table Date: Sat, 15 Apr 2000 06:05:54 -0700 From: Anya & Fred Humphrey, Anya & Fred Humphrey To: teres@aiko.com Daus, this is really cool! They certainly make a strong case for low mass with high rigidity, don't they? This is making carbon fibre sound worthy of more investigation, and I'll have to rethink the sand table altogether. Air bladders still seem like a good idea, but I was struck by their use of damping in the supports (or damping "of" the support). I suppose this could be done tonearm style with large horizontal discs in cylinders of viscous fluid next to each air bladder. Thanks for posting the site. Fred ----- Original Message ----- From: "Daus Studenberg" To: Sent: Friday, April 14, 2000 2:02 AM Subject: [teres] vibration table > > > > Hey Everyone, > > > > Today, I was fortuante to have a tour of the microscale > > heat transfer laboratory when the optical bench that > > they had there caught my eye. It was all metal and > > must have been extremely damped. I would tap it and I > > couldn't feel the vibrations with my other finger > > around it anywhere. It was unlike anything else I have > > seen. Check out the website at www.mellesgriot.com. I > > think a Teres platter mounted on something like this > > would make a really "high tech" look. Of course, I > > could imagine it would cost an arm and a leg to get > > though!! :) However, they have this GREAT section on > >vibration damping and principles. > > > > Just though you guys would be interested, > > Daus > > Subject: Re: [teres] vibration table Date: Sat, 15 Apr 2000 22:39:28 -0700 From: Steve Zettel, Steve Zettel To: teres@aiko.com on 4/15/00 11:58, Daus Studenberg at daus@ufl.edu wrote: > They sure do. If I were going to use this approach, I would almost want to > by one of their 1'X2' palters and build the Teres from there. However, it > is VERY expensive, so I probably won't. The technology behind their surface > is the make it EXTREMELY rigid to the point of preventing vibrations at all > and damping residual ones. Like I said, it works because I after never > seen anything like it damped so well. I am not quite sure if we could get > the same effect over shear mass. However,I have been entertaining the idea > of using carbon fiber and it looks like a good idea. I have been thinking > about phenolic as well. A favorite surplus materials supplier the I know of > sells surplus 3/4" phenolic board. Now THAT is rigid!! My problem with > that is I don't know if you can (or would WANT) to cut it with a table saw. > > Another idea for the drawing board!! > Daus Hi, Daus I had been toying with the carbon fiber idea, but the high costs have kept me from really exploring it. However, your phenolic material would be very good. I would be very interested in some of the surplus boards you wrote of. We use phenolic material quite extensively for insulating boards, stand-offs, etc in the hydroelectric generating facility where I am a chief Control Room operator. It is very machinable and cuttable with hand or power tools. The trick, as in any quality fabrication effort, is to have very sharp tools and work with steady, gentle pressure when feeding the material. Fast enough to avoid burning the material, but not so fast that it bogs down the power tool, or starts chipping out. Fine toothed carbide cutting tools work very well. Thanks for your research. Steve Z near Libby, MT Subject: [teres] Dust covers as Faraday boxes Date: Sun, 16 Apr 2000 17:11:01 -0700 From: Pablo Roufogalis L., Pablo Roufogalis L. To: teres@aiko.com Hello again, Ever had radio operators being captured by your phono circuit? I have always been curious about making a clear dust cover that has wire mesh embedded in it. It would work as a Faraday box, to avoid radio frequencies entering the phono cartridge and circuit. Does anyone have an idea on how small the holes in the wire mesh must be? With a copper plates in the turntable base, the radio isolation would be complete. This has been more of a Teresday afternoon ;-) Regards, Pablo Roufogalis L. papablo@aretecnica.com (se dice papablo atencion de aretecnica punto com) ¡Arrobas NO!. Visite http://www.aretecnica.com/fam/od.htm Visite http://www.aretecnica.com/fampg.htm Subject: Re: [Highfidelity] [JN][teres] isolate TT Date: Sun, 16 Apr 2000 19:30:43 -0700 From: David Dlugos, David Dlugos To: Highfidelity@egroups.com CC: teres@aiko.com; sound@lists.io.com; Tim_Bailey@medibank.com.au; custserv@pearl-hifi.com Tim, >isolating box which could generate a partial vacuum to increase acosutic >isolation of a TT. > >D.Dlugos at 'Highfidelity'. And perhaps it was Bill? >at Pearl Audio who had the set-up and demo'd it? That's my story. I was telling about a visit i made to Bill's where he showed me his modified Linn (a record clamp for instance). I was sure he was generting a partial vacuum. When i quizzed him very recently, he said that it was just airtight. (Maybe we just talked about the possibilities of vacuum). There sure was a difference between top closed & top open. Maybe Bill can put his spin on this. dave ____________________________________ Transmission Line Speaker Page http://www.t-linespeakers.org/ Martin J. King's Focal TL get the pdf now, web version in the works Subject: [teres] VTA adjustment via a sub-chassis Date: Sun, 16 Apr 2000 21:17:15 -0700 From: Pablo Roufogalis L., Pablo Roufogalis L. To: teres@aiko.com Hello to all. It would be great if the arm were affixed to a separate section that could be raised or lowered to optimize VTA in arms that don't have this capability. Such as mine ;-) It seems from the digest that subchassis, armboard and suspension are the areas where there are no clear guidelines so far, and also where many members of the group would like to do a personal design. In my case, I'm having visions of the small inflated tires from RC planes used as isolators in a floating chassis, one in each corner with a minimum of three. In fact, the Micro-Seiki feet in my Thorens use a similar design and provide all the isolation I need. Other feet I tried never passed my feedback isolation test. They are expensive ergo credible said Igor ;-) Look sexy too. The test is to simply rest the cartridge on top of a non-turning Lp and crank the volume all the way. Do it slowly as if your setup is not well isolated you'll get a feedback howl. I'm also concerned about the high walls of the platter picking airborne vibrations. The platter mat may attenuate some but it's better if they never reach the platter at all. Perhaps the actual "final" tables could be used as prototypes for a "best-of-breed" design to be established in the coming years, after many auditions at members houses with the de rigueur single malts and similar niceties to be provided by the gentle host who undoubtly would like to create the best possible atmosphere for appreciating his achievement. BTW, do we have already a ballpark figure for the cost of the bearing, spindle and platter? Regards, Pablo Roufogalis L. papablo@aretecnica.com (se dice papablo atencion de aretecnica punto com) ¡Arrobas NO!. Visite http://www.aretecnica.com/fam/od.htm Visite http://www.aretecnica.com/fampg.htm Subject: Re: [teres] Dust covers as Faraday boxes Date: Mon, 17 Apr 2000 07:14:03 -0700 From: George Munger, George Munger To: teres@aiko.com Hi! I also had an interference problem, but it was emi; not rf. A few years ago, I needed to reduce emi interference (hum), between closely spaced audio components and so I tried to make my own emi blocker, by using some aluminum window screen material, between an acrylic sandwich. The screening is an inexpensive, cooperative and accessible material. The outer tinted acrylic sandwich layer sheets, were no more than .25 inches thick. It worked very well, audibly, although I did not (and still don't) know what instruments I would use to measure emi in this situation. GM >>> Pablo Roufogalis L. 04/16 7:07 PM >>> Hello again, Ever had radio operators being captured by your phono circuit? I have always been curious about making a clear dust cover that has wire mesh embedded in it. It would work as a Faraday box, to avoid radio frequencies entering the phono cartridge and circuit. Does anyone have an idea on how small the holes in the wire mesh must be? With a copper plates in the turntable base, the radio isolation would be complete. This has been more of a Teresday afternoon ;-) Regards, Pablo Roufogalis L. papablo@aretecnica.com (se dice papablo atencion de aretecnica punto com) ¡Arrobas NO!. Visite http://www.aretecnica.com/fam/od.htm Visite http://www.aretecnica.com/fampg.htm Subject: Re: [teres] Dust covers as Faraday boxes Date: Mon, 17 Apr 2000 13:34:44 -0700 From: Steve Zettel, Steve Zettel To: teres@aiko.com Hi, Pablo > Hello again, > > Ever had radio operators being captured by your phono circuit? The only time it has been a problem for me has been when I have used unshielded phono wire outside of the armtube (ET 1). Since I am an amateur radio operator, I usually transmit with my tranceiver and check the effectiveness of all my household electronic equipment -- telephones, stereos, answering machines, television, etc. If everything is fine then my sheilding and grounding is effective against other outside emitters. > > I have always been curious about making a clear dust cover that has wire > mesh embedded in it. It would work as a Faraday box, to avoid radio > frequencies entering the phono cartridge and circuit. In more densely populated areas than Libby, Montana, or in higher RF fields I suppose RF could be picked up by the phono cartridge or small lengths of phono wire exposed at the end of the tonearm, but they are a very small fraction of a wavelength, even at VHF frequencies. > > Does anyone have an idea on how small the holes in the wire mesh must be? For HF frequencies (2-30mHz) the holes could be quite large, 2 inches or 50mm would still be quite effective. > > With a copper plates in the turntable base, the radio isolation would be > complete. True. > > This has been more of a Teresday afternoon ;-) Ouch! Steve Z Subject: [teres] Castable, High Loss Epoxy Composite Date: Wed, 24 May 2000 21:22:53 -0700 From: PEARL Cust Serv, PEARL Cust Serv To: teres@aiko.com Hi All: While looking for XY positioners for the mirrors in a laser interferometer I plan to build for looking at loudspeaker diaphragms, I came across a castable, high loss epoxy composite used for machine tool bases and the like. See the URL below for more details: I've NOT contacted these people so you are on your own: http://www.anorad.com/f_onlineCatalog.htm Best regards, Bill - PEARL, Inc. Subject: [teres] Armboards Date: Thu, 25 May 2000 21:48:10 -0700 From: Edgar Dapiton, Edgar Dapiton To: teres@aiko.com Hello guys I am a new-commer to the world of DIY & am very interested with this Teres project. I see that you've already had such long discussions now and I am learning a lot from all of you - THANKS! I have been wanting to be clarified on this - is it really necessary that the armboard be somehow connected to the ttable chasis or body or frame or whatever you may call it? Will it be "unintelligent" if a completely separate armboard, made out of a massive material, be constructed and installed with no connection to the table itself, say, similar to the outboard motors of some tables whose only contact with our unit is via thin string or belt? What are we actually after here? Vibration control? Noise? If we strain so much on designing a real-quite and stable frame or plinth or chassis to mount our platter/bearing assembly, why not separate the armboard? I'm sure it's adjustment with respect to distance, height, levelness, etc. will not be that difficult. Comments please. Best regards Edgar ___________________________________________________________________________ Edgar Z. Dapiton Regional Risk Engineer & IT Coordinator Swiss Reinsurance Company 19D Tower One, Ayala Triangle Ayala Avenue, Makati City 1200 Manila Phone: 63 2 7553319 Fax: 63 2 7594343 ___________________________________________________________________________ Subject: Re: [teres] Castable, High Loss Epoxy Composite Date: Fri, 26 May 2000 04:20:05 -0700 From: Ivan Anderson, Ivan Anderson To: teres@aiko.com Mmmm... Nice one, Bill. This "Anocast' looks very promising. I wonder what the operating bandwidth is. I found the impulse trace and the following statement quite comforting, as it seems to confirm my own ideas about vibration dissipation (which I tried to expound, in a somewhat disjointed manner, in this place). "The impulse responses of the specimens, presented in the four comparison plots, indicate that the aluminum and Anocast composite samples have a higher initial response to a unit force impulse, but that the vibration amplitude of the Anocast composite bar decays in a fraction of the time required to dissipate the vibrations in the other samples." I suspect that the Anocast material will not accept and dissipate high frequency vibration, and may need a layer of something in between it and the source that will. Ivan. ----- Original Message ----- From: "PEARL Cust Serv" To: Sent: Thursday, 25 May 2000 15:21 Subject: [teres] Castable, High Loss Epoxy Composite > Hi All: > While looking for XY positioners for the mirrors in a laser > interferometer I plan to build for looking at loudspeaker diaphragms, I came > across a castable, high loss epoxy composite used for machine tool bases and > the like. > See the URL below for more details: I've NOT contacted these people so > you are on your own: > > http://www.anorad.com/f_onlineCatalog.htm > > Best regards, > Bill - PEARL, Inc. > > > Subject: Re: [teres] Castable, High Loss Epoxy Composite Date: Fri, 26 May 2000 08:17:35 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com Actually, it sounds like the composite will pass more of the initial impulse (shock), and less of the "tail" (overhang), not necessarily in a frequency associated manner. Additional damping does seem indicated. Igor --- Ivan Anderson wrote: > Mmmm... > > Nice one, Bill. > > This "Anocast' looks very promising. I wonder what > the operating > bandwidth is. > > I found the impulse trace and the following > statement quite comforting, > as it seems to confirm my own ideas about vibration > dissipation (which I > tried to expound, in a somewhat disjointed manner, > in this place). > > "The impulse responses of the specimens, presented > in the four > comparison plots, indicate that the aluminum and > Anocast composite > samples have a higher initial response to a unit > force impulse, but that > the vibration amplitude of the Anocast composite bar > decays in a > fraction of the time required to dissipate the > vibrations in the other > samples." > > I suspect that the Anocast material will not accept > and dissipate high > frequency vibration, and may need a layer of > something in between it and > the source that will. > > Ivan. > > > > > > ----- Original Message ----- > From: "PEARL Cust Serv" > To: > Sent: Thursday, 25 May 2000 15:21 > Subject: [teres] Castable, High Loss Epoxy Composite > > > > Hi All: > > While looking for XY positioners for the > mirrors in a laser > > interferometer I plan to build for looking at > loudspeaker diaphragms, > I came > > across a castable, high loss epoxy composite used > for machine tool > bases and > > the like. > > See the URL below for more details: I've NOT > contacted these > people so > > you are on your own: > > > > > http://www.anorad.com/f_onlineCatalog.htm > > > > Best regards, > > Bill - PEARL, Inc. > > > > > > > __________________________________________________ Do You Yahoo!? Kick off your party with Yahoo! Invites. http://invites.yahoo.com/ Subject: RE: [teres] Armboards Date: Fri, 26 May 2000 10:59:29 -0700 From: Epstein, Jeremy, Epstein, Jeremy To: 'teres@aiko.com' Welcome, Edgar. With reference to the PCB work, that project is pretty far along and I don't think there would be any benefit in taking it offshore at this point. Ron Welborne could probably comment further on this. As far as the arm mount situation is concerned, my understanding is that you want the arm to be completely and totally stable as far as its position related to the platter and disc. If you could achieve that with the seperate structure, I suppose it would be OK but I am not sure it is as good a solution as having it rigidly coupled to the platter mounting. Note that TT's with a "bouncy" suspension (Thorens, AR) always have the arm and platter mounted to the same structure, this is an exaggeration of the same effect but it points out why you need to have this coupling. Otherwise you will get unwanted information vibrating your stylus related to the difference between the structures' positions, unrelated to the music signal. I'm not trying to pee in your Wheaties, I am just summarizing (my understanding of) some of the discussion you've missed here. (The discussion gets pretty spirited at times, you have been warned!) Welcome aboard! -j ========================================= Jeremy Epstein........jepstein@ndbcap.com ========================================= Subject: Re: [teres] Armboards Date: Sun, 28 May 2000 10:17:23 -0700 From: Thom Mackris / Joan Panzella, Thom Mackris / Joan Panzella To: teres@aiko.com Hi Edgar, Jeremy summarizes the separate armboard design constraints quite well. Throughout all of the dialogs in this project, there were some who chose to explore alternative, involved, and most likely uncompromising means of attaining analog nirvana. Each of us had a different hot button as far as which dragon to hunt down and slay. A dialog ensued over the detached arm block and there were several people whom I resepect greatly who have chosen to approach and solve the inherrent design constraints which Jeremy exponded on . Others will be attacking the multiple idler pulley problem with smilar abandon Solving both of the above problems requires impeccable execution. Anything less, IMHO will leave you worse off than when you started. For this reason, I will leave such complexity for future experimentation. As Ken Schei once said to me "what good would it be if you were done ? " ... or words to that effect. Cheers, Thom ----- Original Message ----- From: Epstein, Jeremy To: Sent: Friday, May 26, 2000 7:08 AM Subject: RE: [teres] Armboards Welcome, Edgar. With reference to the PCB work, that project is pretty far along and I don't think there would be any benefit in taking it offshore at this point. Ron Welborne could probably comment further on this. As far as the arm mount situation is concerned, my understanding is that you want the arm to be completely and totally stable as far as its position related to the platter and disc. If you could achieve that with the seperate structure, I suppose it would be OK but I am not sure it is as good a solution as having it rigidly coupled to the platter mounting. Note that TT's with a "bouncy" suspension (Thorens, AR) always have the arm and platter mounted to the same structure, this is an exaggeration of the same effect but it points out why you need to have this coupling. Otherwise you will get unwanted information vibrating your stylus related to the difference between the structures' positions, unrelated to the music signal. I'm not trying to pee in your Wheaties, I am just summarizing (my understanding of) some of the discussion you've missed here. (The discussion gets pretty spirited at times, you have been warned!) Welcome aboard! -j ========================================= Jeremy Epstein........jepstein@ndbcap.com ========================================= Subject: [teres] Great Starter Subchassis! Date: Fri, 2 Jun 2000 00:57:11 -0700 From: Daus Studenberg, Daus Studenberg To: teres@aiko.com Hi everyone, I couldn't help but notice the "Alder Body Blanks" in the Carvin catalog. They are meant for the DIY guitar maker, but I think they would make a great starter subchassis for those who really want a VERY easy setup up for the Teres. Yes it is solid wood, but it is also 1.75" thick! The actual dimensions are: 1.75'' x 13.75" x 20". Almost too prefect for our applications. Route out the underside and apply a sheet of lead to control resonances. Put some quality gel stain on the top and this makes for a VERY professional appearance. The big plus for this is that it has been precision machined flat on all sides, so the platter will be PERFECTLY aligned with the tonearm. Check it out at www.carvin.com. I like this, because I was going to make a temporary setup before the actual construction of the "real deal". Basically, I would have something to enjoy records on and learn about what tweaks work and don't work so that I can finalize a design. Besides, I have yet to figure out how I am going to precision cut and mill three layers of 5/8" thick phenolic and contrained layer composite! Let alone find an appropriate veneer glue that will adhere to it. :P Daus Subject: RE: [teres] Great Starter Subchassis! Date: Fri, 2 Jun 2000 08:14:27 -0700 From: Epstein, Jeremy, Epstein, Jeremy To: 'teres@aiko.com' There are also other places to get guitar body blanks in more-exotic woods like curly and birdseye maple, I can probably come up with their names with some digging at home if anyone is interested. I think Carvin has a good price IIRC. -j ========================================= Jeremy Epstein........jepstein@ndbcap.com ========================================= > -----Original Message----- > From: Daus Studenberg [mailto:daus@ufl.edu] > Sent: Friday, June 02, 2000 6:04 AM > To: teres@aiko.com > Subject: [teres] Great Starter Subchassis! > > > Hi everyone, > > I couldn't help but notice the "Alder Body Blanks" in the > Carvin catalog. > They are meant for the DIY guitar maker, but I think they > would make a great > starter subchassis for those who really want a VERY easy > setup up for the > Teres. Yes it is solid wood, but it is also 1.75" thick! The actual > dimensions are: 1.75'' x 13.75" x 20". Almost too prefect for our > applications. Route out the underside and apply a sheet of > lead to control > resonances. Put some quality gel stain on the top and this > makes for a VERY > professional appearance. The big plus for this is that it has been > precision machined flat on all sides, so the platter will be PERFECTLY > aligned with the tonearm. Check it out at www.carvin.com. > I like this, > because I was going to make a temporary setup before the > actual construction > of the "real deal". Basically, I would have something to > enjoy records on > and learn about what tweaks work and don't work so that I can > finalize a > design. Besides, I have yet to figure out how I am going to > precision cut > and mill three layers of 5/8" thick phenolic and contrained > layer composite! > Let alone find an appropriate veneer glue that will adhere to it. :P > > Daus > Subject: RE: [teres] Great Starter Subchassis! Date: Fri, 2 Jun 2000 11:38:41 -0700 From: Epstein, Jeremy, Epstein, Jeremy To: 'Alex Mitaru'; 'teres@aiko.com' OK, here's a couple : Stewart-MacDonald Guitar Shop Supply www.stewmac.com Exotic Woods Company http://www.exoticwoods.com/bodies.html The Wood Well www.thewoodwell.com Luthiers Mercantile www.lmii.com Of these, I have dealt with only Stewart-MacDonald and they are excellent service-wise. All except the Wood Well I know to have been in business for over five years, the wood well is completely a question mark to me. If we go this route we may be better off buying bulk lumber and chopping it up our own selves. Results will be guaranteed to be beautiful but who knows about the sound? -j ========================================= Jeremy Epstein........jepstein@ndbcap.com ========================================= > -----Original Message----- > From: Alex Mitaru [mailto:alexmi@omneon.com] > Sent: Friday, June 02, 2000 12:44 PM > To: JEpstein@ndbcap.com > Subject: RE: [teres] Great Starter Subchassis! > > > At 10:10 AM 6/2/00 -0400, you wrote: > >There are also other places to get guitar body blanks in > more-exotic woods > >like curly and birdseye maple, I can probably come up with > their names with > >some digging at home if anyone is interested. I think Carvin > has a good > >price IIRC. > > I would love that info...thanks a lot, alex > > ____________________________________________________________________ > Alexandru Mitaru > alexmi@omneon.com > System Architect (503) > 533-0621 ext 228 > Omneon Video Networks (503) 533-5811 FAX > Subject: [teres] motor housing Date: Fri, 2 Jun 2000 20:37:54 -0700 From: steve brooks, steve brooks To: teres@aiko.com Is anyone else planning on mounting their motor in a cylindrical housing...sort of like the VPI SAMA? I would be most interested in learning how...I seem to remember someone mentioning using some stainless pipe...but how would you attatch the motor mounting plate to a steel pipe? And to create a chamber for mass loading....would you have discs of metal welded inside the pipe to create a chamber.. All those high school years spent in college prep classes...I should have taken more shop!! Steve Brooks Decatur,GA Subject: Re: [teres] motor housing Date: Fri, 2 Jun 2000 21:46:23 -0700 From: Steve Zettel, Steve Zettel To: teres@aiko.com on 6/2/00 23:34, steve brooks at brookss@bellsouth.net wrote: > Is anyone else planning on mounting their motor in a cylindrical > housing...sort of like the VPI SAMA? I would be most interested in learning > how...I seem to remember someone mentioning using some stainless pipe...but > how would you attatch the motor mounting plate to a steel pipe? And to > create a chamber for mass loading....would you have discs of metal welded > inside the pipe to create a chamber.. > All those high school years spent in college prep classes...I should have > taken more shop!! > > Steve Brooks > Decatur,GA > I am considering thick-wall brass or aluminum tubing. The walls have to be thick enough to drill holes and tap them to fasten the top plate. The bottom the same. Lead shot or lead fishing weights can be loose in the bottom. Steve Z near Libby, MT Subject: [teres] Stands & Vibes Date: Mon, 12 Jun 2000 13:46:15 -0700 From: Thom Mackris, Thom Mackris To: Teres_List Chris will be following up in much more detail along with a website update, but I just *had* to get my experiences out to the list for all of you who are contemplating turntable stands. Chris & I have collaborated on equipment & turntable stands ... mostly his design with some kibbitzing from me. The equipment stands are 4 sandboxes approximately 3.5" high (MDF) bolted together by four cherry struts (1.25" x 3.5"). While not welded steel (and perhaps a bit less rigid), they are quite aesthetic with a very high spouse approval factor. The turntable stand consists of four MDF posts, 5" square which are filled with concrete with a threaded rod running through it. The posts are bolted via this rod to top and bottom plates of double layer MDF. A 5" high sandbox sits on top of this (optionally floating on an air bladder above the top plate). Because of moving & packing tasks, my stands are quite a ways from being finished but I got a listen to the improvement in Chris' system yesterday and I'm motivated to complete this project toute de suite. With respect to the turntable stand, I'm debating cutting a circular hole in the top plate in order to reduce the (resonant) panel area while still providing structural support to hold the posts in place. An alternative would be to make the top plate into a small sandbox, although perhaps this is overkill. Having experienced improvements in stands, I still never dreamed that a basically untweaked Thorens TD 165 could sound so good (Benz Glider notwithstanding). Here's the interesting part and something that Igor wisely pointed out back in January. When you rap on the sides of the sandboxes, it feels like cement - totally dead. Tapping on the top plate, even on the amp stands (75 lbs worth of iron and chassis!) is not nearly so dead. Those of you who were on the list in January might remember Igor's comments when we were debating seating the base directly in a sandbox. He commented that a flat plate will not get you there and that we should consider screwing cones into the bottom of the plate prior to sinking it into the stand in order to enhance coupling. Once again, he was right on in his observations. Cheers, Thom Subject: Re: [teres] Stands & Vibes Date: Mon, 12 Jun 2000 14:12:06 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com Will there be some pictures? I would like to see this. For those who follow up on Thom's observations, the cutout to reduce the resonant area is an excellent idea. If circumstances of siting do not permit this, an additional cone in the middle of the panel, to control the center of the panel by improving coupling to the sand, is well advised. Igor --- Thom Mackris wrote: > Chris will be following up in much more detail along > with a website update, > but I just *had* to get my experiences out to the > list for all of you who > are contemplating turntable stands. > > Chris & I have collaborated on equipment & turntable > stands ... mostly his > design with some kibbitzing from me. The equipment > stands are 4 sandboxes > approximately 3.5" high (MDF) bolted together by > four cherry struts (1.25" x > 3.5"). While not welded steel (and perhaps a bit > less rigid), they are > quite aesthetic with a very high spouse approval > factor. > > The turntable stand consists of four MDF posts, 5" > square which are filled > with concrete with a threaded rod running through > it. The posts are bolted > via this rod to top and bottom plates of double > layer MDF. A 5" high > sandbox sits on top of this (optionally floating on > an air bladder above the > top plate). Because of moving & packing tasks, my > stands are quite a ways > from being finished but I got a listen to the > improvement in Chris' system > yesterday and I'm motivated to complete this project > toute de suite. With > respect to the turntable stand, I'm debating cutting > a circular hole in the > top plate in order to reduce the (resonant) panel > area while still providing > structural support to hold the posts in place. An > alternative would be to > make the top plate into a small sandbox, although > perhaps this is overkill. > > Having experienced improvements in stands, I still > never dreamed that a > basically untweaked Thorens TD 165 could sound so > good (Benz Glider > notwithstanding). > > Here's the interesting part and something that Igor > wisely pointed out back > in January. When you rap on the sides of the > sandboxes, it feels like > cement - totally dead. Tapping on the top plate, > even on the amp stands (75 > lbs worth of iron and chassis!) is not nearly so > dead. > > Those of you who were on the list in January might > remember Igor's comments > when we were debating seating the base directly in a > sandbox. He commented > that a flat plate will not get you there and that we > should consider > screwing cones into the bottom of the plate prior to > sinking it into the > stand in order to enhance coupling. Once again, he > was right on in his > observations. > > Cheers, > Thom __________________________________________________ Do You Yahoo!? Yahoo! Photos -- now, 100 FREE prints! http://photos.yahoo.com Subject: Re: [teres] Stands & Vibes Date: Tue, 13 Jun 2000 21:54:31 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com CC: Chris Brady Beautiful work, Chris! I've attached a simple drawing of some basic modes of sandbox implementation. The drawing is as simple as it can be, having been quickly layed out by eye in Paint. Conversion to .jpg roughened it, but it should still serve adequately as a clarification, perhaps of benefit to some of us. Chris, I am copying you on it as I do not know if the Teres mail system will accept it, being close to 40K, should you think it useful. Igor --- Chris Brady wrote: > I just updated my web page with some new pictures > and a > brief description. Check it out: > > http://reality.sgi.com/cbrady/audio/ > > Chris > > Igor Kuznetsoff wrote: > > > > Will there be some pictures? I would like to see > > this. > > > > For those who follow up on Thom's observations, > the > > cutout to reduce the resonant area is an excellent > > idea. If circumstances of siting do not permit > this, > > an additional cone in the middle of the panel, to > > control the center of the panel by improving > coupling > > to the sand, is well advised. > > > > Igor > > > > --- Thom Mackris wrote: > > > Chris will be following up in much more detail > along > > > with a website update, > > > but I just *had* to get my experiences out to > the > > > list for all of you who > > > are contemplating turntable stands. > > > > > > Chris & I have collaborated on equipment & > turntable > > > stands ... mostly his > > > design with some kibbitzing from me. The > equipment > > > stands are 4 sandboxes > > > approximately 3.5" high (MDF) bolted together by > > > four cherry struts (1.25" x > > > 3.5"). While not welded steel (and perhaps a > bit > > > less rigid), they are > > > quite aesthetic with a very high spouse approval > > > factor. > > > > > > The turntable stand consists of four MDF posts, > 5" > > > square which are filled > > > with concrete with a threaded rod running > through > > > it. The posts are bolted > > > via this rod to top and bottom plates of double > > > layer MDF. A 5" high > > > sandbox sits on top of this (optionally floating > on > > > an air bladder above the > > > top plate). Because of moving & packing tasks, > my > > > stands are quite a ways > > > from being finished but I got a listen to the > > > improvement in Chris' system > > > yesterday and I'm motivated to complete this > project > > > toute de suite. With > > > respect to the turntable stand, I'm debating > cutting > > > a circular hole in the > > > top plate in order to reduce the (resonant) > panel > > > area while still providing > > > structural support to hold the posts in place. > An > > > alternative would be to > > > make the top plate into a small sandbox, > although > > > perhaps this is overkill. > > > > > > Having experienced improvements in stands, I > still > > > never dreamed that a > > > basically untweaked Thorens TD 165 could sound > so > > > good (Benz Glider > > > notwithstanding). > > > > > > Here's the interesting part and something that > Igor > > > wisely pointed out back > > > in January. When you rap on the sides of the > > > sandboxes, it feels like > > > cement - totally dead. Tapping on the top > plate, > > > even on the amp stands (75 > > > lbs worth of iron and chassis!) is not nearly so > > > dead. > > > > > > Those of you who were on the list in January > might > > > remember Igor's comments > > > when we were debating seating the base directly > in a > > > sandbox. He commented > > > that a flat plate will not get you there and > that we > > > should consider > > > screwing cones into the bottom of the plate > prior to > > > sinking it into the > > > stand in order to enhance coupling. Once again, > he > > > was right on in his > > > observations. > > > > > > Cheers, > > > Thom > > > > __________________________________________________ > > Do You Yahoo!? > > Yahoo! Photos -- now, 100 FREE prints! > > http://photos.yahoo.com __________________________________________________ Do You Yahoo!? Yahoo! Photos -- now, 100 FREE prints! http://photos.yahoo.com --------------------------------------------------------------------- Name: Sndbx2.JPG Sndbx2.JPG Type: JPEG Image (image/jpeg) Encoding: base64 Subject: Re: [teres] Teres construction Date: Fri, 16 Jun 2000 00:18:44 -0700 From: Chris Brady, Chris Brady To: teres@aiko.com > Question: How did you bond the resins & leadshots into a semingly solid > constituent? > > TNX & Mabuhay! > Edgar Nothing special, I just poured in the resin and then added the lead. The lead shot is heavy enough that it just sinks to the bottom. I just kept adding resin and lead until the tube was full. Since about 2/3's of the volume is lead the shrinkage is far less than with resin only. The result is a solid mass. I am sure that the resin does not bond well to the lead, but the resin forms around the pellets. It probably is not very strong, but it does not need to be. Chris Subject: [teres] surface plates Date: Fri, 16 Jun 2000 01:36:35 -0700 From: phclark, phclark To: Mike Larosa CC: Teres Rutland Tool has 18" x 24" x 3" black granite surface plates on sale until 7/8/00 for $74.25. Actually, there's a 24" x 36" @ $145.20, as well, but the sumbitch weighs 400#. Perhaps excessive. Peter C Subject: Re: [teres] surface plates Date: Fri, 16 Jun 2000 07:28:08 -0700 From: Roscoe Primrose, Roscoe Primrose To: teres@aiko.com phclark wrote: > > Rutland Tool has 18" x 24" x 3" black granite surface plates on sale until > 7/8/00 for $74.25. Actually, there's a 24" x 36" @ $145.20, as well, but > the sumbitch weighs 400#. Perhaps excessive. > > Peter C You got any contact info for them? Peace -- Roscoe Primrose -- mailto:roscoe@aiko.com -- http://www.aiko.com/roscoe "Once in a while you get shown the light In the strangest of places if you look at it right." Robert Hunter "640K ought to be enough for anybody" , Bill Gates, 1981 Subject: Re: [teres] Teres construction Date: Fri, 16 Jun 2000 09:37:07 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com Nice work, Chris. Will you be leaving the aluminum au naturel, painting, or clear coating to prevent tarnish discoloration? Igor --- Chris Brady wrote: > After months of planning and thinking I have > actually > started my Teres construction :)) I just finished > my subchassis > and it was surprisingly easy to build. The result > is remarkably > well damped. I put together a web page with some > pictures and > comments. Take a look: > > > http://reality.sgi.com/cbrady/audio/teres/build.html > > I feel like a kid waiting for Christmas!! > > Chris __________________________________________________ Do You Yahoo!? Send instant messages with Yahoo! Messenger. http://im.yahoo.com/ Subject: Re: [teres] surface plates Date: Fri, 16 Jun 2000 09:44:07 -0700 From: phclark, phclark To: teres@aiko.com ----- Original Message ----- From: "Roscoe Primrose" To: Sent: Friday, June 16, 2000 6:28 AM Subject: Re: [teres] surface plates > phclark wrote: > > > > Rutland Tool has 18" x 24" x 3" black granite surface plates on sale until > > 7/8/00 for $74.25. Actually, there's a 24" x 36" @ $145.20, as well, but > > the sumbitch weighs 400#. Perhaps excessive. > > > > Peter C > > You got any contact info for them? > > Peace 800 289-4787. Catalogue key is 0600JT. www.rutlandtool.com Model #9000 1404. It's what I'm planning to use as a plinth. Right handy that they decide to put them on sale now. Dunno about freight though... the 18 x 24 weighs 150#. Peter C Subject: Re: [teres] Teres construction Date: Fri, 16 Jun 2000 09:55:39 -0700 From: Chris Brady, Chris Brady To: teres@aiko.com I was planning to use a brushed finish and then add a clear coat. I may try polishing the aluminum, but it is difficult to get a uniform finish. Chris > > Nice work, Chris. Will you be leaving the aluminum > au naturel, painting, or clear coating to prevent > tarnish discoloration? > > Igor > > --- Chris Brady wrote: > > After months of planning and thinking I have > > actually > > started my Teres construction :)) I just finished > > my subchassis > > and it was surprisingly easy to build. The result > > is remarkably > > well damped. I put together a web page with some > > pictures and > > comments. Take a look: > > > > > > http://reality.sgi.com/cbrady/audio/teres/build.html > > > > I feel like a kid waiting for Christmas!! > > > > Chris > > __________________________________________________ > Do You Yahoo!? > Send instant messages with Yahoo! Messenger. > http://im.yahoo.com/ Subject: RE: [teres] Teres construction Date: Fri, 16 Jun 2000 10:05:36 -0700 From: Epstein, Jeremy, Epstein, Jeremy To: 'teres@aiko.com' Paint it black, you devil! -j, channeling one of my favorite test discs, "Get Yer Ya-Yas Out" ========================================= Jeremy Epstein........jepstein@ndbcap.com ========================================= > -----Original Message----- > From: Igor Kuznetsoff [mailto:gorkuz@yahoo.com] > Sent: Friday, June 16, 2000 11:35 AM > To: teres@aiko.com > Subject: Re: [teres] Teres construction > > > Nice work, Chris. Will you be leaving the aluminum > au naturel, painting, or clear coating to prevent > tarnish discoloration? > > Igor > > > --- Chris Brady wrote: > > After months of planning and thinking I have > > actually > > started my Teres construction :)) I just finished > > my subchassis > > and it was surprisingly easy to build. The result > > is remarkably > > well damped. I put together a web page with some > > pictures and > > comments. Take a look: > > > > > > http://reality.sgi.com/cbrady/audio/teres/build.html > > > > I feel like a kid waiting for Christmas!! > > > > Chris > > > __________________________________________________ > Do You Yahoo!? > Send instant messages with Yahoo! Messenger. > http://im.yahoo.com/ > Subject: Re: [teres] surface plates Date: Fri, 16 Jun 2000 10:19:18 -0700 From: phclark, phclark To: teres@aiko.com BTW, I just checked with the local store in Phx (I buy my taps and dies from these folks). They will honor the price even if they are out of stock. There is no freight to a local store, but it's fob CA if it has to be shipped common carrier. The cost of freight on 150# LTL would buy a lot of gas, I suspect. You CO types could finance the trip to Phx with the savings on a few of them. Peter C ----- Original Message ----- From: "phclark" To: Sent: Friday, June 16, 2000 8:38 AM Subject: Re: [teres] surface plates > > ----- Original Message ----- > From: "Roscoe Primrose" > To: > Sent: Friday, June 16, 2000 6:28 AM > Subject: Re: [teres] surface plates > > > > phclark wrote: > > > > > > Rutland Tool has 18" x 24" x 3" black granite surface plates on sale > until > > > 7/8/00 for $74.25. Actually, there's a 24" x 36" @ $145.20, as well, > but > > > the sumbitch weighs 400#. Perhaps excessive. > > > > > > Peter C > > > > You got any contact info for them? > > > > Peace > > > 800 289-4787. Catalogue key is 0600JT. www.rutlandtool.com Model #9000 > 1404. > > It's what I'm planning to use as a plinth. Right handy that they decide to > put them on sale now. Dunno about freight though... the 18 x 24 weighs > 150#. > > Peter C > > > > Subject: Re: [teres] Teres construction Date: Fri, 16 Jun 2000 10:24:29 -0700 From: phclark, phclark To: teres@aiko.com ----- Original Message ----- From: "Chris Brady" To: Sent: Friday, June 16, 2000 8:54 AM Subject: Re: [teres] Teres construction > I was planning to use a brushed finish and then add a clear > coat. I may try polishing the aluminum, but it is difficult > to get a uniform finish. > > Chris Yaaah, you high tech types. Don't you know this is a legacy "technology?" In order to apply the proper amount of soul to this, ya gotta use brass, lovingly hand polished and lacquered. :-) Peter C Subject: RE: [teres] Teres construction Date: Fri, 16 Jun 2000 10:27:26 -0700 From: David Suess, David Suess To: teres@aiko.com After looking at Chris' design "in the flesh", I am revising my own plans for my Teres TT. However, not having the facilities for cutting all that metal, I think I'll build a similar design, but substitute Corian all the way around. I have more than enough for the baseplate, bearing support, and armboard components from some castoff pieces from someone's kitchen project. And it was all FREE! I had planned on building a plinth of multiple layers of birch plywood, using the Corian as a top plate and armboard. But I like Chris' design much better and I think it will ultimately be easier for me to build. The hardest part will be taking a raggedy-edged sink cutout and squaring it up to the size I need. I am humbled by the ingenuity of others, but bold enough to steal their work. But I am very appreciative... - david suess Subject: Re: [teres] surface plates Date: Fri, 16 Jun 2000 11:31:27 -0700 From: Steve Zettel, Steve Zettel To: teres@aiko.com on 6/16/00 01:35, phclark at phclark@uswest.net wrote: > Rutland Tool has 18" x 24" x 3" black granite surface plates on sale until > 7/8/00 for $74.25. Actually, there's a 24" x 36" @ $145.20, as well, but > the sumbitch weighs 400#. Perhaps excessive. > > Peter C > > Air-Gas has a slightly smaller 12"X 18"X 3" black granite plate (80 lbs) at right around $60.00 on sale. Are these things drill-able? Steve Z near Libby, MT USA Subject: Re: [teres] surface plates Date: Fri, 16 Jun 2000 11:49:21 -0700 From: phclark, phclark To: teres@aiko.com Sure. Peter C ----- Original Message ----- From: "Steve Zettel" To: Sent: Friday, June 16, 2000 10:29 AM Subject: Re: [teres] surface plates > on 6/16/00 01:35, phclark at phclark@uswest.net wrote: > > > Rutland Tool has 18" x 24" x 3" black granite surface plates on sale until > > 7/8/00 for $74.25. Actually, there's a 24" x 36" @ $145.20, as well, but > > the sumbitch weighs 400#. Perhaps excessive. > > > > Peter C > > > > > Air-Gas has a slightly smaller 12"X 18"X 3" black granite plate (80 lbs) at > right around $60.00 on sale. > > Are these things drill-able? > > Steve Z > near Libby, MT USA > > Subject: Re: [teres] surface plates Date: Fri, 16 Jun 2000 13:51:33 -0700 From: phclark, phclark To: teres@aiko.com FWIW, my catalogue (Airgas/Rutland) has the 12 x 18 for $43.25, on sale. Peter C ----- Original Message ----- From: "Steve Zettel" To: Sent: Friday, June 16, 2000 10:29 AM Subject: Re: [teres] surface plates > on 6/16/00 01:35, phclark at phclark@uswest.net wrote: > > > Rutland Tool has 18" x 24" x 3" black granite surface plates on sale until > > 7/8/00 for $74.25. Actually, there's a 24" x 36" @ $145.20, as well, but > > the sumbitch weighs 400#. Perhaps excessive. > > > > Peter C > > > > > Air-Gas has a slightly smaller 12"X 18"X 3" black granite plate (80 lbs) at > right around $60.00 on sale. > > Are these things drill-able? > > Steve Z > near Libby, MT USA > > Subject: Re: [teres] Stands & Vibes Date: Sat, 24 Jun 2000 02:34:55 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com Edgar, The problem with the top plate is about the most basic force there is on this earth besides sex - gravity. While this force works to plaster the sand tightly to the bottom & sides of the box structure, it works to *separate* the sand from the top plate. That is why Chris built his sandboxes with the top plates unattached to the remainder of the box structure. Had he attached them, a gap would have formed between the top & sand, no matter how well the box was filled. The next problem was to get good contact between the plate & sand. Just laying the tops on the sand cannot accomplish this because no matter how you try to flatten the top surface of the sand, there is no significant force, other than the weight of whatever is resting on top (and this will not accomplish enough) to bond the two intimately enough. The result, if seen under a microscope, will be of the plate resting on a small number of high points, and the actual contact area will be, well, microscopic. Press it down, pound on it, vibrate it, threaten it with bad music, wave crystals & chant hooks from hit tunes, but a good bond you cannot get. There are two basic advantages to be gleaned from using sand: mass loading and a place to "sink" vibration. Well, maybe, three - it's cheap. To achieve mass loading of the box structure, only filling it is necessary. This is good for creating a composite which is heavy & difficult for air or structure borne vibration to push around, so to speak, helping to create an isolative barrier to these. The other useful quality is the ability of sand to sink vibration within itself, due to the mass of loose, relatively random grains which work to kill the acoustic power of the wavefront traveling within it by both vibrating grains against each other, and diffusing the wavefront via the randomness of the grain faces. This can be further improved with the addition of recycled tire rubber chips, but I won't get into that now (again). Just look up the old posts where I got into that at length. That is what the phrase "good internal damping" alludes to. To take advantage of this, good coupling to the sand is necessary. That is why Chris sought to improve the contact area via the stiffening cleats, as Thom reports. Only, I don't believe that the assumedly rectangular cross section of the cleats is actually advantageous to this end, because they present the same horizontal surfaces at their bottoms as the plate itself would. They may, in fact be deleterious because they would tend to lift the remainder of the plate off the sand, leaving it uncontacted by the sand, and, therefore, undamped, while not improving the intimacy of contact the way cones can. Had they been, say, triangular in cross section, they would have gained more advantage in the same way as cones would. The way cones work in sand is due to increasing contact area. If you think about the shape of the cone, you will realize that as weight presses the cone into the sand, the contact area increases very quickly, until equilibrium is reached between the weight supported & resistance offered by the cone to further sinking, given that everything is sized right. The idea is to *not* allow the plate or structure supported by the cone to come to rest on the sand. If that happens, it may just about as well be resting on the sand without the cones, because the weight would then be distributed across that surface, rather than being pressed hard to the sand at the cones, allowing tight contact which is capable of sinking vibration. If this happens, it means that either the cones are too small, or the tip angle is too small (a blunter cone is needed), or more cones are needed. In a word - tuning. Given a properly tuned system, leveling is a non-issue. Simply press your structure where needed to bed it down in the sand, until it is level. The additional force you exert should be all that is needed over & above equilibrium. At this point, I would like to mention that the use of a top plate, while both intuitively (at first glance) and cosmetically reasonable, in a conventional sort of way, and, perhaps, also practical in terms of the ease of changing out the components sited on it, is *not*, to my thinking optimum. If you have gotten the impression, from all this that getting a top plate to behave ideally is difficult, I suspect you are right. You might even consider the complication of adding a damping treatment to a cone suspended top plate. But why bother? Wouldn't it be more advantageous (and simpler) to bypass the top plate altogether, and site the *component* *directly* on the sand, via cones??? This would allow the component direct access to the mass of the sand, as well as direct vibration sinking, without the coupling losses, hassles, & extra work needed to make those plates. I didn't draw such a configuration in my quickie sketch, but just substitute, mentally, a component for the top plate, and you've got the idea. Alternately, if isolation is more important for the component to be sited, just use an inner tube in between, as per the bottom sketch. If the idea of setting components directly on sand sounds cosmetically odd to you (or your mate), consider the use of a thin top layer of any of a number of attractive or colorful sands for an attractive & unusual touch, to turn what might be an objectionable oddity into an unusual & interestingly novel design feature. My machine will be a minimal-area subchassis spiked directly to sand via cones. There is a quite bit more to it than just that, involving direct vibration sinking paths through the bearing (which is designed to accept a cone mounting thread, for those of you who are recent & are unaware of this) and ditto for the arm mounting structure, and more, but enough for now. Hope this helps. Igor --- Thom Mackris wrote: > Edgar, > > Some annecdotal information. Chris just finised his > sandbox equipment > stands - check the link off his website. When you > rap on the side of the > sandboxes, they're totally dead - they feel like > concrete. The top plate > still has a fairly significant resonance when you > rap on it. This is even > the case on the stands for his amplifier power > supply chassis which weighs > in excess of 50 lbs. > > Chris had partially applied Igor's coupling theory > by gluing MDF cleats > (strips of approx. 1/2" x 1/2" cross section) on the > bottom of the top plate > to (a) stiffen the top plate and (b) increase > contact area with the stand. > Perhaps these helped, but the top plates are still > "boingy woingy". > > The theory as I understand it is anything you can do > to better couple the > top plate to the stand will improve matters. > > Cheers, > Thom > > > ----- Original Message ----- > From: Edgar Dapiton > Cc: > Sent: Friday, June 23, 2000 12:06 AM > Subject: Re: [teres] Stands & Vibes > > > > Hello Igor > TNX for your very informative insights. > I see that Thom & you agree on the use of cones > under that flat alum plate. > I wish to ask now, for my own benefit > (and also for those just like me) - could you please > expound a little why > the tip-toes or cones are necessary > for sitting the sub-chassis into the sandbox? > Wouldn't the weight of the > the whole thing just sink the feet and have > the large alum area touch the sand again? What > about the issue of > levelling? I still have no experience in these > things > that's why I am very interested in learning and > understanding more how this > works so I can also adapt them. > > My very best > Edgar > > > > > > Igor Kuznetsoff on 06/14/2000 > 11:53:01 AM > > > To: teres@aiko.com > cc: Chris Brady > Subject: Re: [teres] Stands & Vibes > > > > > ================== > I've attached a simple drawing of some basic modes > of > sandbox implementation. The drawing is as simple as > it can be, having been quickly layed out by eye in > Paint. Conversion to .jpg roughened it, but it > should > still serve adequately as a clarification, perhaps > of > benefit to some of us. > ================== > Simple but very understandable. > > > > For those who follow up on Thom's observations, > > the cutout to reduce the resonant area is an > excellent > > > idea. If circumstances of siting do not permit > > this, an additional cone in the middle of the > panel, to > > > control the center of the panel by improving > > coupling to the sand, is well advised. > > > > > > Igor > > > > > > > Those of you who were on the list in January > > might > > > > remember Igor's comments > > > > when we were debating seating the base > directly > > in a > > > > sandbox. He commented > > > > that a flat plate will not get you there and > > that we > > > > should consider > > > > screwing cones into the bottom of the plate > > prior to > > > > sinking it into the > > > > stand in order to enhance coupling. Once > again, > > he > > > > was right on in his > > > > observations. > > > > > > > > Cheers, > > > > Thom > > > > > > Received: from iss04.interliant.com > ([198.64.193.194]) by > Internet-505.interliant.com (Lotus SMTP MTA v1.2 > (600.1 3-26-1998)) with > SMTP id 862568FE.001784E7; Tue, 13 Jun 2000 23:16:53 > -0500 > Received: (from root@localhost) > by iss04.interliant.com (8.9.3/8.9.3) id > XAA09871 > for > [IN]edgar_dapiton/SwissRe%RCOMINT%RCOMNET%interliant%inbound@smtpgw.interli > ant.com; Tue, 13 Jun 2000 23:16:50 -0500 (CDT) > Received: from ripple.aiko.com > (roscoe.c.crosslink.net [207.199.131.65]) > by iss04.interliant.com (8.9.3/8.9.3) with > ESMTP id XAA09742 > for ; Tue, 13 Jun > 2000 23:16:38 -0500 (CDT) > > Received: (from majordomo@localhost) > by ripple.aiko.com (8.9.3/8.9.1) id XAA05963 > for teres-list; Tue, 13 Jun 2000 23:17:03 -0500 > Message-ID: > <20000614035301.25091.qmail@web1201.mail.yahoo.com> > Date: Tue, 13 Jun 2000 20:53:01 -0700 (PDT) > From: Igor Kuznetsoff > Subject: Re: [teres] Stands & Vibes > To: teres@aiko.com > Cc: Chris Brady > MIME-Version: 1.0 > Content-Type: multipart/mixed; > boundary="0-596516649-960954781=:22409" > Sender: owner-teres@aiko.com > Precedence: bulk > Reply-To: teres@aiko.com > > > > > > > > __________________________________________________ Do You Yahoo!? Get Yahoo! Mail - Free email you can access from anywhere! http://mail.yahoo.com/ Subject: Re: [teres] dimension dementia Date: Sat, 24 Jun 2000 15:52:37 -0700 From: Chris Brady, Chris Brady To: teres@aiko.com Thom already answered part of the dimension questions, but there are a couple of corrections. 1) Mounting hole size is 1.125". Thom knew this but accidentally typed 1.25. To make sure that the bearing lip seats properly on the top surface I did the following for my subchassis: - drill a small pilot hole all the way through the subchassis - drill a 1.125" hole about .5" deep from the top - drill a 1.25" hole from the bottom until it meets with the 1.125" hole. This insures good seating of the bearing even if the hole is not perfectly perpendicular to the surface. For the 1.125" hole I used a hole saw designed for cutting metal. The result was a hole that is about 1/32" over 1.125". This should be just the right size for the bearing. 2) I am not sure what is being asked, but Thom is correct that the length of the threaded part of the bearing is 2.875". The total distance from the mounting surface for the bearing and the bottom of the platter should be 0.135" (the thickness of the delrin pad). 3) The proposed thickness of the platter was 3" minus a little for machining. However, the 1" acrylic stock that was used is actually 0.92" thick. The final result was a thickness of 2.7". This means that the total height from the mounting surface to the top of the platter should be 2.835". If you use a washer with the bearing the height will be increased by the washer thickness. I don't know about the mounting height for the Rega, but I need to mount my Triplanar arm 1.125" below the platter surface. Chris > > Thom, Chris and group > Those pictures look great. I'm starting construction on my own chassis which > will be a skeletal aluminum T-bar affair. But I need some dimensions and I > can't even find the ones I thought I had. Specifically: > 1) what's the ideal size mounting hole for the bearing? > 2) taking into account the bearing flange and how the spindle > sits in the bearing, what will be the total clearance between chassis > and platter? > 3) is the platter's proposed > thickness still 2 15/16s? > 4) does anyone know if the Rega arm base should be > about an inch below the platter? > Thanks in advance. By the way, if you haven't bought your VTA adjuster yet, > check out the Incognito in the June HiFi+. > Fred Subject: Re: [teres] Stands & Vibes Date: Sat, 24 Jun 2000 23:01:16 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com > The cleats that I added to my top plates are > triangular You were right on top of things, as usual, Chris. Given that you anticipated this properly, I would wonder just how much improvement would be gained by just going to cones. The improvement over(/in addition to) triangular cleats should (I would *guess*) be noticeable, but may or may not be significant enough to be worthwhile without additional extensional damping. Thom's suggestion of cutting out whatever of the middle of the panel that you can may be more effective, particularly if extensional damping is also added, and this is set on cones. FWIW, if we consider the sandboxes to be, in essence, a block-and therefore a filter-between the shelf structure and the component, the top plates would then be *after* the filter, and mostly liable to pickup of airborne noise (not very significant if you consider the acoustic power of that vs. the mass of the plate). In the case of the turntable, there would be the possibility of resonance with motor noise, and the smaller likelihood of possible resonance with bearing noise. Though these are undesirable, I would think that the bigger issue here would really be the ability of the system to sink vibration, rather than resonance, and this would be significant to mostly the 'table, other components being less needy of this function. Perhaps, to this end, you could try foregoing the plate under the 'table, in order to couple directly to the sand (if your Thorens allows the possibility of adding cones somehow / I imagine that your Teres certainly can be set up that way), while beefing up/modifying the plates to deal with these factors under the other components? Igor P.S.-Took a look at the new machining pics. Gorgeous. --- Chris Brady wrote: > Igor Kuznetsoff wrote: > > > That is why Chris sought to improve the > > contact area via the stiffening cleats, as Thom > > reports. Only, I don't believe that the assumedly > > rectangular cross section of the cleats is > actually > > advantageous to this end, because they present > > the same horizontal surfaces at their bottoms as > the > > plate itself would. They may, in fact be > deleterious > > because they would tend to lift the remainder of > the > > plate off the sand, leaving it uncontacted by the > > sand, and, therefore, undamped, while not > improving > > the intimacy of contact the way cones can. Had > they > > been, say, triangular in cross section, they would > > have gained more advantage in the same way as > cones > > would. > > The cleats that I added to my top plates are > triangular. > It seemed that triangular cleats would provide a > better > interface with the sand. But with a simple knuckle > rap > test it does not seem to be any better than just a > flat > top plate. > > The sandboxes did great things for the sound even > though > the top plate seems to be more poorly damped than > expected. > More experimentation is in order. > > Chris __________________________________________________ Do You Yahoo!? Get Yahoo! Mail - Free email you can access from anywhere! http://mail.yahoo.com/ Subject: Re: [teres] Stands & Vibes Date: Sat, 24 Jun 2000 23:09:25 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com Chris Brady wrote: > The cleats that I added to my top plates are > triangular You were right on top of things, as usual, Chris. Given that you anticipated this properly, I would wonder just how much improvement would be gained by just going to cones. The improvement over(/in addition to) triangular cleats should (I would *guess*) be noticeable, but may or may not be significant enough to be worthwhile without additional extensional damping. Thom's suggestion of cutting out whatever of the middle of the panel that you can may be more effective, particularly if extensional damping is also added, and this is set on cones. FWIW, if we consider the sandboxes to be, in essence, a block-and therefore a filter-between the shelf structure and the component, the top plates would then be *after* the filter, and mostly liable to pickup of airborne noise (not very significant if you consider the acoustic power of that vs. the mass of the plate). In the case of the turntable, there would be the possibility of resonance with motor noise, and the smaller likelihood of possible resonance with bearing noise. Though these are undesirable, I would think that the bigger issue here would really be the ability of the system to sink vibration, rather than resonance, and this would be significant to mostly the 'table, other components being less needy of this function. Perhaps, to this end, you could try foregoing the plate under the 'table, in order to couple directly to the sand (if your Thorens allows the possibility of adding cones somehow / I imagine that your Teres certainly can be set up that way), while beefing up/modifying the plates to deal with these factors under the other components? Igor P.S.-Took a look at the new machining pics. Gorgeous. --- Chris Brady wrote: > Igor Kuznetsoff wrote: > > > That is why Chris sought to improve the > > contact area via the stiffening cleats, as Thom > > reports. Only, I don't believe that the assumedly > > rectangular cross section of the cleats is > actually > > advantageous to this end, because they present > > the same horizontal surfaces at their bottoms as > the > > plate itself would. They may, in fact be > deleterious > > because they would tend to lift the remainder of > the > > plate off the sand, leaving it uncontacted by the > > sand, and, therefore, undamped, while not > improving > > the intimacy of contact the way cones can. Had > they > > been, say, triangular in cross section, they would > > have gained more advantage in the same way as > cones > > would. > > The cleats that I added to my top plates are > triangular. > It seemed that triangular cleats would provide a > better > interface with the sand. But with a simple knuckle > rap > test it does not seem to be any better than just a > flat > top plate. > > The sandboxes did great things for the sound even > though > the top plate seems to be more poorly damped than > expected. > More experimentation is in order. > > Chris __________________________________________________ Do You Yahoo!? Get Yahoo! Mail - Free email you can access from anywhere! http://mail.yahoo.com/ Subject: Re: [teres] Stands & Vibes Date: Sun, 25 Jun 2000 11:58:03 -0700 From: MaughanAudio@aol.com, MaughanAudio@aol.com To: teres@aiko.com In a message dated 6/24/00 11:10:25 PM Mountain Daylight Time, gorkuz@yahoo.com writes: << > The cleats that I added to my top plates are > triangular You were right on top of things, as usual, Chris. Given that you anticipated this properly, I would wonder just how much improvement would be gained by just going to cones. The improvement over (in addition to) triangular cleats should be noticeable, but may or may not be significant enough to be worthwhile without additional extensional damping. Thom's suggestion of cutting out whatever of the middle of the panel that you can may be more effective, particularly if extensional damping is also added, and this is set on cones. >> I suggest, A less expensive option would be to use the top plate of thicker material and then have a waffled surface machined into the bottom side. Love those Belgium waffles, seriously (again), the idea is to couple as much surface area of the top plate to the sand. A simple flat plane will tend to float on the surface allowing resonances to also decouple from the sand and stay within the top plate. Adding cones increases surface area and also adds a different density of material to sink energy into. But consider how effective the coupling would be with a deep waffle pattern of the top plate itself. The surface area of contact would greatly be increased, the cross-sectional area of the top plate would be changing thus breaking up resonances and reducing the decay time of those resonances. Something to consider? Until again, Gordon. Subject: Re: [teres] Stands & Vibes Date: Sun, 25 Jun 2000 20:31:27 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com Gordon, I agree with you about thickening the plate, and share with you the appreciation of the look of Belgian waffles. In fact, my fascination with that waffled look goes back to my childhood, when my father showed me some of his work. You know how many large concrete slabs are cast with that pattern on their bottom side to save material & weight while maximizing strength? That was my father's design, back when I was still a wee toddler. He was a steel & concrete structural design specialist, and got that idea during a breakfast from, you guessed it, Belgian Waffles. I also agree with you about the waffling's ability to break up resonances. That was, in fact one of the reasons my father adopted that technique for the project at hand when he came up with that concept. His specialties were earthquake proofing & bridges, so he was well aware of resonance problems. The project in question was a large parking garage with large open spans, so he was concerned about harmonic resonance buildup from heavy vehicles driving through it. That, however, is where the agreements run into short decay time. Given my positing that the problem with top slabs is the lack of intimacy of contact with the sand, I must point out that increasing the surface area of contact will only exacerbate that problem by reducing the pressure of contact per square area. Changing over to cones will actually radically *reduce* the contact area, thereby *increasing* contact *pressure*, which will improve signal transference, even if, as you rightly say, the process would now have to fight the material density changes. I also fail to see how adding a complex pattern to machine into the surface can be cheaper than eliminating the top plate altogether… I would say, in advancement of Waffling, that your idea has merit if applied to the inside surfaces of the bottoms & sides of the "catboxes", as someone cattily termed them some months ago, because *there* gravity works for us, and the increase in surface area becomes useful. The *cost* of waffling, unfortunately, would probably make it impractical (putting aside the lack of necessity at those lower locations), unless one just happens to have CNC milling equipment in their workshop. Hmm…All this talk of waffles is making me hungry. I think I'll go at this point and…Mmm Haagen Dasz on some waffles… Later…, Igor --- MaughanAudio@aol.com wrote: > In a message dated 6/24/00 11:10:25 PM Mountain > Daylight Time, > gorkuz@yahoo.com writes: > > << > The cleats that I added to my top plates are > > triangular > > You were right on top of things, as usual, Chris. > Given that you anticipated this properly, I would > wonder just how much improvement would be gained by > just going to cones. The improvement over (in > addition to) triangular cleats should be > noticeable, but may or may not be > significant enough to be worthwhile without > additional > extensional damping. Thom's suggestion of cutting > out > whatever of the middle of the panel that you can > may > be more effective, particularly if extensional > damping > is also added, and this is set on cones. >> > > I suggest, > > A less expensive option would be to use the top > plate of thicker material > and then have a waffled surface machined into the > bottom side. > Love those Belgium waffles, seriously (again), the > idea is to couple as much > surface area of the top plate to the sand. A simple > flat plane will tend to > float on the surface allowing resonances to also > decouple from the sand and > stay within the top plate. Adding cones increases > surface area and also adds > a different density of material to sink energy into. > But consider how > effective the coupling would be with a deep waffle > pattern of the top plate > itself. The surface area of contact would greatly be > increased, the > cross-sectional area of the top plate would be > changing thus breaking up > resonances and reducing the decay time of those > resonances. > Something to consider? > Until again, Gordon. __________________________________________________ Do You Yahoo!? Get Yahoo! Mail - Free email you can access from anywhere! http://mail.yahoo.com/ Subject: Re: [teres] Stands & Vibes Date: Mon, 26 Jun 2000 21:50:59 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com IMHO, only if it is necessary for domestic or logistic considerations, these being individual choices. The best sounding top would, I think, be no top at all (does that sound familiar?), as well as cheapest. Also, oddball that I may be, I like the idea of taking advantage of the opportunity to create an *unusual* cosmetic. There are a lot of attractive sands around in many colors, including a shiny jet black sand used for sandblasting. It is fairly cheap, and literally *sparkles*, for example. Very pretty. And a lot cheaper than a top with waffling. Additionally, you would still want, I think, to add cones for the reasons I cited previously, in order to keep the waffling itself *off* the sand. Igor --- steve brooks wrote: > > Igor said: > > The *cost* > > of waffling, unfortunately, would probably make it > > impractical (putting aside the lack of necessity > at > > those lower locations), unless one just happens to > > have CNC milling equipment in their workshop. > > Nick McKinney of Lmbda Acoustics has access to a > partner with a CNC machine > and lots of experience with wood and other speaker > making materials. Nick > said even though he dropped out of the project he > would be happy to help. > I'm sure we are all using different size boxes...but > we could have a 2'x3' > sand box top made (for example), and then each be > responsible for cutting > them down ourselves to fit out individual boxes. > What do you think...worth the trouble? > > Steve Brooks __________________________________________________ Do You Yahoo!? Get Yahoo! Mail - Free email you can access from anywhere! http://mail.yahoo.com/ Subject: Re: [teres] Stands & Vibes Date: Tue, 27 Jun 2000 08:39:39 -0700 From: Thom Mackris, Thom Mackris To: teres@aiko.com I have to agree with Igor on this one. If cosmetics dictate a top rather than decorative sand, then cut large holes in the area wher the tip toes bed into the sand. Cheers, Thom ----- Original Message ----- From: Igor Kuznetsoff To: Sent: Monday, June 26, 2000 9:48 PM Subject: Re: [teres] Stands & Vibes IMHO, only if it is necessary for domestic or logistic considerations, these being individual choices. The best sounding top would, I think, be no top at all (does that sound familiar?), as well as cheapest. Also, oddball that I may be, I like the idea of taking advantage of the opportunity to create an *unusual* cosmetic. There are a lot of attractive sands around in many colors, including a shiny jet black sand used for sandblasting. It is fairly cheap, and literally *sparkles*, for example. Very pretty. And a lot cheaper than a top with waffling. Additionally, you would still want, I think, to add cones for the reasons I cited previously, in order to keep the waffling itself *off* the sand. Igor --- steve brooks wrote: > > Igor said: > > The *cost* > > of waffling, unfortunately, would probably make it > > impractical (putting aside the lack of necessity > at > > those lower locations), unless one just happens to > > have CNC milling equipment in their workshop. > > Nick McKinney of Lmbda Acoustics has access to a > partner with a CNC machine > and lots of experience with wood and other speaker > making materials. Nick > said even though he dropped out of the project he > would be happy to help. > I'm sure we are all using different size boxes...but > we could have a 2'x3' > sand box top made (for example), and then each be > responsible for cutting > them down ourselves to fit out individual boxes. > What do you think...worth the trouble? > > Steve Brooks __________________________________________________ Do You Yahoo!? Get Yahoo! Mail - Free email you can access from anywhere! http://mail.yahoo.com/ Subject: Re: [teres] Stands & Vibes Date: Tue, 27 Jun 2000 10:31:06 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com Lest I mislead anyone into a mistake, or waste anyone's money on more decorative sand than necessary, I should mention that it is advisable that the decorative sand only be a top layer. The black sand blasting type I used as an example, for instance, is a volcanic pumice of a completely unusable consistency & grain configuration to work well acoustically for us, and should be used as a relatively thin cosmetic top layer only. Other colored sands are likely to be just fine effect-wise, most being ordinary sand that has just been colored, but there is no need to spend the premium money filling the whole sandbox with it. Ordinary clean-grade "sanitized play sand", available at any building materials store, as well as other outlets, is cheap & commonly available, works just right. I have also used white "silica sand", the sort we often see in those standup ashtrays in many places, and love the way it looks, but have some concern over its smaller, more regular particle size & grain facets. It packs more tightly than ordinary (yellowish) play sand, and that could result in less of that grain-to-grain rubbing that results in good "internal damping" under vibration, as well as wavefront dispersion, which I mentioned earlier. It does, however result in a higher mass/density, which is good, OTH. Bagged play sand , BTW, conveniently has less dust and is "sanitized", as compared to, say cement mixing grade sand which may also be a rougher mix of less than optimum particle sizes), or other "plainer" or bulk sands. Don't underestimate the nuisance caused by the dust of some sands while working with it, especially indoors while, say, filling your sandbox in your living room. Keeping a vacuum running with the hose end over the work site while filling, I found, will help considerably in controlling the dust nuisance. Just don't lay the hose right down *on* the sand! Colored sands are available in many places, but the easiest to find can be obtained from pet stores carrying pet fish & accessories. Sand meant for such use is, additionally, the cleanest & most dust-free. Please keep in mind that many such have a larger than optimum grain size from an acoustic standpoint, vis-a-vis filling the entire box due to a cleanliness-over-cost consideration. Should a cosmetic top layer be disturbed enough to bring up the sand underneath, it can be touched up with a bit more sand, so consider keeping a bit of extra around. Igor --- Thom Mackris wrote: > I have to agree with Igor on this one. If cosmetics > dictate a top rather > than decorative sand, then cut large holes in the > area wher the tip toes bed > into the sand. > > Cheers, > Thom > > ----- Original Message ----- > From: Igor Kuznetsoff > To: > Sent: Monday, June 26, 2000 9:48 PM > Subject: Re: [teres] Stands & Vibes > > > IMHO, only if it is necessary for domestic or > logistic > considerations, these being individual choices. The > best sounding top would, I think, be no top at all > (does that sound familiar?), as well as cheapest. > Also, oddball that I may be, I like the idea of > taking > advantage of the opportunity to create an *unusual* > cosmetic. There are a lot of attractive sands > around > in many colors, including a shiny jet black sand > used > for sandblasting. It is fairly cheap, and literally > *sparkles*, for example. Very pretty. And a lot > cheaper than a top with waffling. Additionally, you > would still want, I think, to add cones for the > reasons I cited previously, in order to keep the > waffling itself *off* the sand. > > Igor > > > --- steve brooks wrote: > > > > Igor said: > > > The *cost* > > > of waffling, unfortunately, would probably make > it > > > impractical (putting aside the lack of necessity > > at > > > those lower locations), unless one just happens > to > > > have CNC milling equipment in their workshop. > > > > Nick McKinney of Lmbda Acoustics has access to a > > partner with a CNC machine > > and lots of experience with wood and other speaker > > making materials. Nick > > said even though he dropped out of the project he > > would be happy to help. > > I'm sure we are all using different size > boxes...but > > we could have a 2'x3' > > sand box top made (for example), and then each be > > responsible for cutting > > them down ourselves to fit out individual boxes. > > What do you think...worth the trouble? > > > > Steve Brooks > > > __________________________________________________ > Do You Yahoo!? > Get Yahoo! Mail - Free email you can access from > anywhere! > http://mail.yahoo.com/ > __________________________________________________ Do You Yahoo!? Get Yahoo! Mail - Free email you can access from anywhere! http://mail.yahoo.com/ Subject: Re: [teres] Stands & Vibes Date: Tue, 27 Jun 2000 18:32:10 -0700 From: MaughanAudio@aol.com, MaughanAudio@aol.com To: teres@aiko.com In a message dated 6/27/00 9:54:06 AM Mountain Daylight Time, gorkuz@yahoo.com writes: << I should mention that it is advisable that the decorative sand only be a top layer. >> Forget decorative sand, simply cover any exposed openings with black rubber sheeting. One could go even further and make a top plate with holes in it as suggested but the construction would use an upper layer and a lower layer. Before assembling the two layers, simply run a router along all edges set to cut a quater inch or so in from the edge at a depth equal or a few thousandths less than the thickness of the rubber sheet to use. Then the sheet is cut to fit all voids including the shelf. After which the two layers are laminated together sandwiching in the rubber sheet as a permanent gasket. This gasket could even extend to the edge of the sandbox. The edge lip of the sand box would then have a top rail applied to fasten the rubber gasket to the edge. Easy cleanup, no spilt sand, and no litter box (if you have cats). Until again, Gordon. Subject: Re: [teres] motor mounting plate Date: Fri, 7 Jul 2000 12:21:29 -0700 From: Thom Mackris, Thom Mackris To: teres@aiko.com Hi Alex, Yes, the motor is about 1" diameter, although I don't have the exact dimensions. Chris is out of town until Monday, but if memory serves (remember, I''m dimensionally challenged ) the bottom of the motor projects about 45 mm below the surface of the mounting plate. The motor mounting plate diameter (brought to you by the folks at Teres ) is yet another attempt at universality and flexibility. Many folks wanted a cylindrical motor pod - originally, I wasn't one of them, BTW. In order to accomodate this, without necessarily affecting the square pod contingent (of which I was one), the circular plate was designed. Chris B. and Ron Welborne took the ball and ran with designing a donut shaped circuit board to mount under a circular mounting plate, with the motor passing through the donut hole and the circuit board mounting to the plate via standoffs. This allowed for a completely self contained unit if this was a design priority for an individual. Squeezing the parts onto the board was quite a design effort and even at this size, required a two sided circuit board. Having a mounting plate any smaller would have raised the degree of difficulty of producing a high quality board that is also easy to solder. I'm sympathetic with your goal of trying to keep your Teres compact, but I don't see a simple solution for mounting the motor on the chassis with this plate. If you route a rebate into the chassis so that the plate clears the bottom of the platter, you'll be limiting the height adjustment of the pulley relative to the platter. This might work, but it will take some fiddling. I also think that having the motor in a fixed position, so close to the platter (i.e. less than 2.25" radius of the plate) will cost you in flexibility. It's my guess that we'll experience subtle changes with differing belt lengths and materials (audible? beats me) due to the change in the frequencies that differing belt lengths will pass to the platter. Additionally, a fixed position motor/pulley will probably limit you to using a rubber belt - with a less compliant belt, material, mounting the belt and getting proper tension on the system will have you cussing and fuming. Although a rubber belt might not be all that bad, you're tweaking opportunities will be limited and you just might be forced to listen to your record collection , Cheers, Thom ----- Original Message ----- From: Alex Mitaru To: Sent: Friday, July 07, 2000 10:59 AM Subject: Re: [teres] motor mounting plate I couldn't remember the size of the motor, but I'm suspecting that the diameter is around 1"...is this true? If it is, why have we designed such a large (4.5") mounting plate? I'm contemplating mounting the motor relatively close to the platter (on the same chassis, though I don't really have any idea how) and a 4.5" mounting plate is rather large... What is the total height (length) of the motor including the shaft and pulley? thanks a lot, alex ____________________________________________________________________ Alexandru Mitaru alexmi@omneon.com System Architect (503) 533-0621 ext 228 Omneon Video Networks (503) 533-5811 FAX Subject: Re: [teres] motor mounting plate Date: Fri, 7 Jul 2000 16:13:30 -0700 From: Thom Mackris, Thom Mackris To: Teres_List Alex, Yes, a dust cover has been an area of concern for me too - at least for when the 'table is not in use. I've been struggling to attain a compact design in order to accomplish this. On my Merrill, which comes with no dust cover other than a soft plastic folding cover, I did the following: The 'table sits on an open frame stand (the Archidee, which is much like the Target or Linn stands in appearance). I built a a box with no top & no bottom which sits over the turntable stand, forming a sleeve around it, if you will. I then made a fake plinth which rests on this sleeve, along with a hinged dust cover which closes over this fake, outer plinth. The sleeve, fake plinth and dust cover do *not* touch the turntable ... in fact they isolate the turntable from external vibrations, at least to some extent. The problem I'm having with the Teres concept is that I'm building the same stand that Chris built (he's ahead of me, of course). Because it's impractical to build an outer shell to surround this 24" high stand plus sandbox, I'm thinking of a removable dust cover as opposed to a hinged one. The problem with a removable dust cover is that I'd hate to screw up at the end of the evening ... spacey & tired after listening to music - dropping the dust cover onto the tonearm A sliding dust cover would work, but I'm trying to think of something better. My idea for a sliding cover is to route a small (1/4") square rebate around the front and two sides of either a) the supporting sandbox or b) the plinth. These rebates would help me to guide the dust cover in place with little possibility of screwup. The back of the sandbox or plinth would be extended to form the back of the dust cover. This arrangement would certainly accomodate a full-width dust cover (i.e. ~ 25") in that it wouldn't be too unwieldy to place on the 'table. Any comments? I'm still not totally satisfied but need to cat-proof the whole affair. A note about hinged dust covers. With my Merrill, the dust cover is also open backed. The rear of the fake plinth extends upward to form the rear surface of the dust cover. This was done primarily because of the hinges I was able to source at the time. With the Teres and the 3" high platter, hinging this way (as opposed to from the bottom of a dustcover) would almost be a necessity in order for the dust cover to clear the top of the plattae as it hinges upwards. Cheers, Thom ----- Original Message ----- From: Alex Mitaru To: Thom Mackris Sent: Friday, July 07, 2000 1:47 PM Subject: Re: [teres] motor mounting plate At 12:19 PM 7/7/00 -0600, you wrote: >Chris B. and Ron Welborne took the ball and ran with designing a donut >shaped circuit board to mount under a circular mounting plate, with the >motor passing through the donut hole and the circuit board mounting to the >plate via standoffs. thanks Thom, yes, you are right, I forgot about the circuit board...well, if I mount the motor on the chassis, I could install the circuit board somewhere else... The main reason I'm thinking the motor on the chassis is that I would like to build a cover/lid for the whole thing...yes, I'm aware that I'll have significantly less flexibility, but, I'll probably do it if I find a half decent solution... thanks again for the info/advice, alex > ____________________________________________________________________ Alexandru Mitaru alexmi@omneon.com System Architect (503) 533-0621 ext 228 Omneon Video Networks (503) 533-5811 FAX Subject: Re: [teres] motor/platter belt Date: Sat, 8 Jul 2000 23:17:49 -0700 From: Thom Mackris / Joan Panzella, Thom Mackris / Joan Panzella To: teres@aiko.com I'm thinking that we have an awful lot of stuff to sort out and numerous cheap belt materials available which make a $30 belt something that we do 6 months to a year from now if at all. I'm not trying to be a crumudgeon about this, but think of all of the work we have yet to do as well as all of the available belt materials we have available: fishing line, fly line, dental floss, magnetic recording tape, cheap rubber belts from MCM Electronics ... the list boggles the mind! The good Doctor Wilimzig (SP #10) along with Manfred have had great success with magnetic recording tape on their Verdier & Scheu respectively. I'd guess that the less compliant belts would be most revealing of flaws in our setup. Even if they are not the belt we ultimately want to end up with, they will serve as a great magnifying glass to help us troubleshoot our setup. When I'm dialing in a new cartridge, I disable the silicone damping on my Audiocraft arm. After I get everything dialed in, I add damping to taste. I intend to follow the same recipe with the Teres setup vis a vis belts. Mind you, it might end up that these Kapton belts are superior (BTW, what *is* Kapton?), but I figure that we have time. As Ken Schei once said "what good would it be if you were through?" or words to that effect. Cheers, Thom ----- Original Message ----- From: phclark To: Sent: Saturday, July 08, 2000 10:35 AM Subject: Re: [teres] motor/platter belt I suppose this is worth pursuing. But, I suspect that getting agreement from a significant number of terestrials on a common length might well prove to be impossible. Assuming they work and are otherwise felicitous, two would be a lifetime supply and cost a significant multiple of my pod cost. Having said that, is there *any* consensus from two dozen terestrials (prepared to buy two ea.) on *one* length? Additionally, is there a possibility of getting a sample for, say Chris, to try out, since he's the only one with a running 'table? I think the proposal has merit, but may prove to be difficult to implement without some kind of test drive. My $0.02. Peter C Subject: Re: [teres] motor/platter belt Date: Sat, 8 Jul 2000 23:22:40 -0700 From: Thom Mackris / Joan Panzella, Thom Mackris / Joan Panzella To: teres@aiko.com Yup ... exactly why I'll start with dental floss and magnetic tape. Cheers, Thom ----- Original Message ----- From: Jon Lane To: Sent: Saturday, July 08, 2000 5:53 PM Subject: RE: [teres] motor/platter belt IMHO, isolation gets more billing than it may deserve. We should ask ourselves what it is we are isolating. In this case, the motor planned for most Teres tables is a quiet regulated DC affair with a high degree of control and imperceptible rumble as far as the Teres platter is concerned. In precisely motivating the platter, the task falls to the motor to regulate speed. If the motor is regulated to this end, any compliance in the drive system reduces the regulation's effectiveness. A precedence exists in the excellent article by Dr. Gotz Wilimzig in SP #10. He advocates heavy tape driven platters and small, responsive dc motors. Jon Lane Subject: Re: [teres] Stands & Vibes Date: Tue, 11 Jul 2000 00:37:29 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com My expectations is a good way to put it, George. It would be guesswork indeed at this point because this would depend on the individual chassis weights, and how many cones would be used, plus allowance (or not) for any decorative top plate on the sand. My chassis will use 4 cones (3 perimeter+ 1 under the bearing), and the chassis won't be very heavy, so the weight will be principally of the platter, plus some. Based on very limited fooling around with cones on sand in the past, I would *guess* that a ~2" height will give enough clearance after the cones sink in and approximately 30-40 Deg. tip angle should work for me. But this is only a fairly wild guess. I've had no reason to mock up anything that resembled my plans previously, and nothing is handy at the moment to try this now. I've no idea how we could standardize cone sizes for as diverse a group of designs as ours will be. Besides the differences in loadings due to the differing total weights divided by the number of cones used, different heights will probably be needed to accommodate top plates (or lack of them), and that's assuming we are talking about using Thom's idea of cutting out the areas of top plates where the cones would pass through. Those that elect to try coning top plates instead would probably want shorter cones. This makes at least three heights already, even with only one top plate thickness, potentially. And, in at least my case, I will have to reconcile differing heights to the bottom of the bearing vs. the bottom of the chassis, and the bottom of the arm mounting assembly. My arm will be spiked to the sand as well via a cone under it, this being one of the 3 perimeter cones. For me,at least, it also gets a bit more complicated yet. The fourth (middle )cone will be under the bearing. As I am a believer in matching the cone material to the material I wish to sink noise from in order to match acoustic impedances, the one under my bearing will have to be made of brass, while the one under the arm of aluminum. The remaining two "outrigger" cones will not be mated to metal, and so will be aluminum, mostly to match the other outer cone (under the arm), so that I have some sort of cosmetic symmetry with the three aluminum cones arranged neatly around the one of brass. Hopefully, the three aluminum ones can be all the same size, and, if I get really lucky, maybe I will even be able to use three off the shelf cones for that. I am reconciled to having a minimum of at least one cone custom machined, probably the brass. Matching materials, for those who will be grounding the bearing, is my tip for that. Otherwise, my preference would run to aluminum, but this, too will no doubt be dependent on individual cosmetic choices where material matching is not needed (or prioritized). Well, I hope I have thoroughly muddled the subject. If you are getting the idea that I don't have really solid clues about the sizes at the moment, you are quite right. If anyone has any suggestions as to how to standardize them...? Igor --- George Munger wrote: > If we did make our own cones, your expectations > would require how high; what angle and made from ? > or ? (choices?) and how many per box? Maybe we > could do a group order.... GM > > >>> Igor Kuznetsoff 06/28 1:35 AM > >>> > Well, whatever floats your boat up onto the beach. > I'm > allergic, and won't own any cats, even if I do like > them, just as I like the idea of decorative sands a > *whole* lot more than all this extra complication, > so, > personally, I think I'll (much more) simply "KISS" > all this extra work off. Thom's idea of just > cutting > openings for the cones does sound a bit easier & > more > practical than all this, though it will require > rather > tall cones, possibly a problem if the tip angle > necessary for a heavy subchassis construction is > large. This does sound quite a bit more > sophisticated, > though. > > Igor > > --- MaughanAudio@aol.com wrote: > > In a message dated 6/27/00 9:54:06 AM Mountain > > Daylight Time, > > gorkuz@yahoo.com writes: > > > > << I should mention that it is advisable that the > > decorative sand only be a top layer. >> > > Forget decorative sand, simply cover any exposed > > openings with black rubber > > sheeting. One could go even further and make a top > > plate with holes in it as > > suggested but the construction would use an upper > > layer and a lower layer. > > Before assembling the two layers, simply run a > > router along all edges set to > > cut a quater inch or so in from the edge at a > depth > > equal or a few > > thousandths less than the thickness of the rubber > > sheet to use. Then the > > sheet is cut to fit all voids including the shelf. > > After which the two layers > > are laminated together sandwiching in the rubber > > sheet as a permanent gasket. > > This gasket could even extend to the edge of the > > sandbox. The edge lip of the > > sand box would then have a top rail applied to > > fasten the rubber gasket to > > the edge. Easy cleanup, no spilt sand, and no > litter > > box (if you have cats). > > Until again, Gordon. > > > __________________________________________________ > Do You Yahoo!? > Get Yahoo! Mail - Free email you can access from > anywhere! > http://mail.yahoo.com/ > __________________________________________________ Do You Yahoo!? Get Yahoo! Mail – Free email you can access from anywhere! http://mail.yahoo.com/ Subject: Re: [teres] Stands & Vibes Date: Tue, 11 Jul 2000 11:18:21 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com George, Good points about both placement & number. You reminded me of a vagrant thought about placement that never made it to print, mostly because it is theoretical due the lack of laser interferometry equipment in most homes. Any flat panel will, under vibration, develop a pattern of flex modes. These would vary according to the frequencies involved, but a sweep would locate areas with the largest displacement, which could also be targeted/prioritized according to the significance of the frequencies involved. Theory would dictate that those would be the places to put the cones for maximum energy transference (that is, noise sinking). Well, now you know. If you happen to know any physicists or other researchers with that sort of equipment, you could try talking them into finding these locations for you, good luck. Realistically speaking, we'll just have to put the cones wherever practicality allows. The "more better" question is less theoretical, OTOH. If we consider that vibration sinking is dependent on the quality/tightness of the contact point (that literally being the "point" of cones: the concentration of pressure on the smallest area practicable for maximum coupling), we realize that there has to be a balance between coupling as much of a vibrating part to "snub" the movement, and the reduction of pressure on the points which will occur due to the addition of more points & the additional area dividing the available pressure. What this means is that the most effective rig will have the *minimum* number of cones necessary to control the panel/part in question. For a flat panel bedded on sand, no center cutout, this would probably be a max of five cones, the fifth in the center, absolute min being three for obvious reasons, but probably inadequate. Igor --- George Munger wrote: > Igor, pretty deep insight, and a good point about > composition matching. I imagine that cone placement > may also affect energy transfer characteristics, but > by how much, I do not know. Also, if we ignore > cosmetics for argument sake, is 'more' always > better? Any cone heads out there? GM > > >>> Igor Kuznetsoff 07/11 2:36 AM > >>> > My expectations is a good way to put it, George. It > would be guesswork indeed at this point because this > would depend on the individual chassis weights, and > how many cones would be used, plus allowance (or > not) > for any decorative top plate on the sand. My > chassis > will use 4 cones (3 perimeter+ 1 under the bearing), > and the chassis won't be very heavy, so the weight > will be principally of the platter, plus some. > Based > on very limited fooling around with cones on sand in > the past, I would *guess* that a ~2" height will > give > enough clearance after the cones sink in and > approximately 30-40 Deg. tip angle should work for > me. > But this is only a fairly wild guess. I've had no > reason to mock up anything that resembled my plans > previously, and nothing is handy at the moment to > try > this now. I've no idea how we could standardize > cone > sizes for as diverse a group of designs as ours will > be. Besides the differences in loadings due to the > differing total weights divided by the number of > cones > used, different heights will probably be needed to > accommodate top plates (or lack of them), and that's > assuming we are talking about using Thom's idea of > cutting out the areas of top plates where the cones > would pass through. Those that elect to try coning > top plates instead would probably want shorter > cones. > This makes at least three heights already, even with > only one top plate thickness, potentially. And, in > at > least my case, I will have to reconcile differing > heights to the bottom of the bearing vs. the bottom > of > the chassis, and the bottom of the arm mounting > assembly. My arm will be spiked to the sand as well > via a cone under it, this being one of the 3 > perimeter > cones. For me,at least, it also gets a bit more > complicated yet. The fourth (middle )cone will be > under the bearing. As I am a believer in matching > the > cone material to the material I wish to sink noise > from in order to match acoustic impedances, the one > under my bearing will have to be made of brass, > while > the one under the arm of aluminum. > The remaining two "outrigger" cones will not be > mated > to metal, and so will be aluminum, mostly to match > the > other outer cone (under the arm), so that I have > some > sort of cosmetic symmetry with the three aluminum > cones arranged neatly around the one of brass. > Hopefully, the three aluminum ones can be all the > same > size, and, if I get really lucky, maybe I will even > be > able to use three off the shelf cones for that. I > am > reconciled to having a minimum of at least one cone > custom machined, probably the brass. Matching > materials, for those who will be grounding the > bearing, is my tip for that. Otherwise, my > preference > would run to aluminum, but this, too will no doubt > be > dependent on individual cosmetic choices where > material matching is not needed (or prioritized). > Well, I hope I have thoroughly muddled the subject. > If you are getting the idea that I don't have really > solid clues about the sizes at the moment, you are > quite right. If anyone has any suggestions as to > how > to standardize them...? > > Igor > > --- George Munger wrote: > > If we did make our own cones, your expectations > > would require how high; what angle and made from ? > > or ? (choices?) and how many per box? Maybe we > > could do a group order.... GM > > > > >>> Igor Kuznetsoff 06/28 1:35 > AM > > >>> > > Well, whatever floats your boat up onto the beach. > > > I'm > > allergic, and won't own any cats, even if I do > like > > them, just as I like the idea of decorative sands > a > > *whole* lot more than all this extra complication, > > so, > > personally, I think I'll (much more) simply "KISS" > > > all this extra work off. Thom's idea of just > > cutting > > openings for the cones does sound a bit easier & > > more > > practical than all this, though it will require > > rather > > tall cones, possibly a problem if the tip angle > > necessary for a heavy subchassis construction is > > large. This does sound quite a bit more > > sophisticated, > > though. > > > > Igor > > > > --- MaughanAudio@aol.com wrote: > > > In a message dated 6/27/00 9:54:06 AM Mountain > > > Daylight Time, > > > gorkuz@yahoo.com writes: > > > > > > << I should mention that it is advisable that > the > > > decorative sand only be a top layer. >> > > > Forget decorative sand, simply cover any > exposed > > > openings with black rubber > > > sheeting. One could go even further and make a > top > > > plate with holes in it as > > > suggested but the construction would use an > upper > > > layer and a lower layer. > > > Before assembling the two layers, simply run a > > > router along all edges set to > > > cut a quater inch or so in from the edge at a > > depth > > > equal or a few > > > thousandths less than the thickness of the > rubber > > > sheet to use. Then the > > > sheet is cut to fit all voids including the > shelf. > > > After which the two layers > > > are laminated together sandwiching in the rubber > > > sheet as a permanent gasket. > > > This gasket could even extend to the edge of the > > > sandbox. The edge lip of the > > > sand box would then have a top rail applied to > > > fasten the rubber gasket to > > > the edge. Easy cleanup, no spilt sand, and no > > litter > > > box (if you have cats). > > > Until again, Gordon. > > > > > > __________________________________________________ > > Do You Yahoo!? > > Get Yahoo! Mail - Free email you can access from > > anywhere! > > http://mail.yahoo.com/ > > > > > __________________________________________________ > Do You Yahoo!? > Get Yahoo! Mail û Free email you can access from > anywhere! > http://mail.yahoo.com/ __________________________________________________ Do You Yahoo!? Get Yahoo! Mail – Free email you can access from anywhere! http://mail.yahoo.com/ Subject: RE: [teres] Stands & Vibes Date: Tue, 11 Jul 2000 13:00:21 -0700 From: Jon Lane, Jon Lane To: teres@aiko.com > Any flat panel will, under > vibration, develop a pattern of flex modes. These > would vary according to the frequencies involved, but > a sweep would locate areas with the largest > displacement, which could also be targeted/prioritized > according to the significance of the frequencies > involved. Theory would dictate that those would be > the places to put the cones for maximum energy > transference (that is, noise sinking). Sounds like you're looking at another frequency-selective set of filters...and all this then renews to thought the larger variable mix of panel stiffness, panel mass, and overall panel damping. These three (and some not mentioned) add together to form the soup of variables we are trying to sort out. Maybe no panel, no chassis, but then the coupling suffers... You know my choice: as much stiffness as possible (variable One back already!) to which we could apply what I would call 'critical' damping, or variable Three. Not so sure about selective points of 'sinking' or contact, which seem to me to be analogous to bracing your speaker box to find new, higher Q and freq modes, even at a reduced level. An alternative would be to stiffen the panel itself to say, an arbitrary level of 100% more than baseline by using more thickness. Presumably, less need then for the external damping (which might itself then work at full contact but at a density less than sand) but then how _much_ mass from the double-thick+ chassis becomes how much of a penalty? And what ratio of internal to external damping (with damping resiliency and internal mechanical sinking factored in) is best? Extrateresindustrial research required. Still very concerned over external acoustical input centered roughly around 250Hz working against the entire sandwich. ANY motion here is NOT easy to deal with; this suggests less chassis mass, not more, and isolation, not coupling. OTOH, much rigid mass = articulate bass, for whatever reason I don't fully know. Meanwhile, internal input is more the arm's problem (and at roughly 2,500Hz) and meanwhile the platter drive should be sufficiently isolated to be out of the picture entirely. Jon Lane (no closer) Subject: RE: [teres] Stands & Vibes Date: Tue, 11 Jul 2000 14:26:59 -0700 From: daus@ufl.edu, daus@ufl.edu To: teres@aiko.com Hey everyone, I couldn't help but notice the talk aobut the modes of a flat plate etc.. My design will take into account the resonant modes of a flat panel. I am still split between a minimalist "X" type shape that is about 4" thick or a traditional flat panel with the motor isolated. Factoring the construction costs in, I will go for the flat plate, but I have a really great way to combine good engineering materials and concepts while maintaining asthetic appeal. My design should look like a Wilson-Bensch design. I developed an Excel spreadsheet that calculates the resonant modes for different materials in a rectangular board type shape. I also calculated our platter and, from what I can remember, it has a resosnant frequency around 30 hz for the first mode. If anyone is interested, I could forward them a copy. Daus Subject: RE: [teres] Stands & Vibes Date: Tue, 11 Jul 2000 22:33:01 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com --- Jon Lane wrote: > > Any flat panel will, under > > vibration, develop a pattern of flex modes. These > > would vary according to the frequencies involved, > but > > a sweep would locate areas with the largest > > displacement, which could also be > targeted/prioritized > > according to the significance of the frequencies > > involved. Theory would dictate that those would > be > > the places to put the cones for maximum energy > > transference (that is, noise sinking). > > > > Sounds like you're looking at another > frequency-selective > set of filters...and all this then renews to thought > the > larger variable mix of panel stiffness, panel mass, > and > overall panel damping. These three (and some not > mentioned) > add together to form the soup of variables we are > trying to > sort out. Maybe no panel, no chassis, but then the > coupling > suffers... I'm all for stiffness, coupled with resonance resistance accomplished by any and all means, internal loss, *and* vibration sinking of whatever makes it through this gauntlet. No opportunity unturned. Good arguments for using *no* top panels in sandboxes, or, at least, avoiding contact with the cosmetic / catproofing treatments, other than maybe rubber ones. Or for avoiding a panel-shaped chassis where the thickness is a small ratio when compared to its other dimensions. Balancing all the factors affecting a chassis is quite a juggling act. Reducing external acoustic pickup would suggest a chassis with minimum external surface, particularly flat areas perpendicular to thin chassis cross-sections. A thick, narrow chassis with a small flat surface area ought to accommodate these parameters. And gives me an opportunity for another trick, too, which will help deal with that pesky internal input from the arm. Igor > > You know my choice: as much stiffness as possible > (variable > One back already!) to which we could apply what I > would call > 'critical' damping, or variable Three. Not so sure > about > selective points of 'sinking' or contact, which seem > to me > to be analogous to bracing your speaker box to find > new, > higher Q and freq modes, even at a reduced level. > > An alternative would be to stiffen the panel itself > to say, > an arbitrary level of 100% more than baseline by > using more > thickness. Presumably, less need then for the > external > damping (which might itself then work at full > contact but at > a density less than sand) but then how _much_ mass > from the > double-thick+ chassis becomes how much of a penalty? > And > what ratio of internal to external damping (with > damping > resiliency and internal mechanical sinking factored > in) is > best? Extrateresindustrial research required. > > Still very concerned over external acoustical input > centered > roughly around 250Hz working against the entire > sandwich. > ANY motion here is NOT easy to deal with; this > suggests less > chassis mass, not more, and isolation, not coupling. > OTOH, > much rigid mass = articulate bass, for whatever > reason I > don't fully know. Meanwhile, internal input is more > the > arm's problem (and at roughly 2,500Hz) and meanwhile > the > platter drive should be sufficiently isolated to be > out of > the picture entirely. > > Jon Lane > (no closer) > > __________________________________________________ Do You Yahoo!? Get Yahoo! Mail – Free email you can access from anywhere! http://mail.yahoo.com/