Subject: Re: [teres] Bases and Vibration Date: Mon, 27 Mar 2000 00:17:44 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com Folks, The black goo, made by 3M, that I've mentioned from time to time works quite nicely at the headshell, far better than blu-tack can. Blu-tack is more massive, but far less absorptive. A polymer coating meant for tool handles called Dip-It works wonders on tone arms. I like it better than arm "wraps". The combination of the two do wonders for a quiet background. Of the two, the goo is easily removable if you don't like it, the coating would be somewhat more difficult. Igor --- Steve Zettel wrote: > on 3/26/00 04:58, Ivan Anderson at ivan@win.co.nz > wrote: > > > Hi Steve, > > > Hi Ivan, > > > Ivan wrote, about my questions concering the > relative strength of chassis vs > > arm vibrations: > > > > Well yes, this type of information would be most > helpful... but there is no > > doubt that the headshell and arm are excited to a > significant degree, as > > witnessed by the change in reproduction character > accompanying a change in arm > > board. > > > I am going to do an experiment to check that out, > changing my existing > acrylic armboard to aluminum. My Oracle has been a > test bed of sorts for > some of our early Teres questions, might as well > continue. > > > However the isolation from external vibration > requires an entirely different > > approach from that needed to absorb and dissipate > internal vibration, and is > > altogether easier to achieve. I can find few > studies into the dissipation of > > the frequency range we need to deal with, but > there are any number dealing > > with the isolation of equipment. > > > Yes indeed. Visiting the Soundown and EAR sites, as > well as any number > addressing resilient mounts proved that to be the > case. > > > Isolation is best achieved (perhaps) by a two step > approach, the use of mass > > and broadly innert material to reject the greatest > band of frequency possible, > > and the damping of the narrow but vicious > fundamental that these materials > > inevitibly have. > > > The other tack would be to accept a greater range of > frequencies, but > hopefully at a lower (near or below audibility) > energy level. Damping could > be applied here, too, I suppose. > > >>> Ivan had also written earlier: > >>> > >>> IMO it is wise to deal with the high frequencies > first. Not only are these > >>> the frequencies that most affect the full > extension of stylus travel and > >>> musical clarity but lower frequencies are still > likely to be transmitted > >>> through the boundary and can be dealt with later > in the chain. > > >> Steve Z postulated in reply: > > >> Seems to make a case for dealing with the > vibrations at the cartridge and > >> headshell first, then the arm tube, then through > the bearing(s) into the > >> base, armboard, etc. At some point they are > attenuated enough to be below the > >> threshold of audibility. One would think. > >> > >> There is a very old trick of using a little > Blu-tack or similar at the > >> headshell or on the cartridge. . . > >> > >> Also tonearm wraps are favored by some. > >> > >> Of course, in a no-holds barred effort, maybe all > of these should be applied! > >> > >Ivan returned: > > > You are right of course, and some experimentation > is called for, however, the > > same considerations are required in this effort as > they are in base / armboard > > design. I imagine that Blu-tack and arm wrap > materials reflect high > > frequencies and alter the transmission properties > of the arm, for better or > > worse, who knows. > > Certainly, Blu-Tack between the cartridge and > headshell might reflect back > energy, but some appreciable amount of energy must > be getting absorbed and > disipated at/in the lossier substance. Ditto armwrap > on the surface of the > arm. After all, this is how extensional damping > works, and it has been > proven to work in industrial and military > applications. Besides, energy is > already being reflected back by the material-to-air > interface already. > > But I agree, besides lowering the energy content at > some range of > frequencies of the arm or headshell or whatever, no > doubt adding the damping > alters the transmission characteristics of the new > damping/base material > system. It doesn't alter the characteristics of the > base material though. > Aluminum is still aluminum, acrylic still acrylic. > > And I also agree, more experimentation is needed. I > plan to also check out > what happens when I add an arm wrap to my Rega > RB-300. One correspondent on > the Phonogram list reports great success with it. > > > > snip > > > >> Steve (in the nature of a question, not statement > of fact): > >> So material matching is one key, but so is > matching mass, and elasticity. > > > Ivan: > > Matching impedence is the goal, of the suitable > materials, judgements are made > > as to practicality, expense, appearance, smell, > etc. > > > >>Steve: > >> At what point to we go from being too massive to > too light? If we for a > >> minute assume an excellent decoupling of our > table from structure borne > >> vibrations (say, suspended by bungee cords), then > the lighter our structure > >> the more susceptible to excitation by acoustic > energy. Of course, we have a > >> built-in lower limit with a 3" thick acrylic > platter coupled by a close > >> tolerance bearing to our chassis! > >> > > After the point where it is just right :-) Both > too light and too massive > > cause the same problem, but we are talking > interfaces here. The system might > > comprise of layers of increasingly dense > materials, and further massive > > components aimed at isolation. > > This would seem to say that one I idea I had, for a > sandwiched construction > of aluminum plate outside, then Isodamp or Dynamat, > and a central core of > styrofoam is not as good an idea as going from outer > layers of aluminum to > denser and denser layers, ending up with a central > core of lead? > > > snip > > > >>Steve: > >> Like maybe a sandwich of two sheets of thin metal > (Al or SS) constraining > >> some Isodamp and perhaps a central core of > styrofoam? The outer surface, > >> except for mounting surfaces, covered with a thin > layer of damping? > >> > > Maybe, but remember while a thin layer of metal > may have a good impedence > > match in itself, as soon as you attach something > else to it you change its > > properties. > > If we don't place the damping between the two > aluminum (for instance) pieces > to be joined then at the interface we have as close > a match as possible. I > am not ignoring that you also mentioned matching > mass and elasticity of the > two materials, but I don't think we are going to > practically have a > chassis/armboard of the same mass as the > arm/headshell. And we would never > be able to apply damping in any case. All I see as > an alternative is as > gentle an impedance transformation from one part to > the other as we go from > component part to another. > === message truncated === __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com Subject: Re: [teres] Bases and Vibration Date: Mon, 27 Mar 2000 00:58:10 -0700 From: Thom Mackris / Joan Panzella, Thom Mackris / Joan Panzella To: teres@aiko.com Yes, the black goo is great stuff... also found in larger quantities as gasket material for automobile windshield installation. 10-15 feet at a Pep Boys, Checker Automobile Supply etc., for ~ $10.00. Igor had previously reported 10 year old stuff remains tacky. Additional good news is that It takes quite a bit of heat to make this stuff ooze, as you'd guess from a product that has to hold up in an Arizona desert with the windows rolled up. Cleanup ... really sticky stuff - citrus solvent works great. Thom ----- Original Message ----- From: Igor Kuznetsoff To: Sent: Sunday, March 26, 2000 11:16 PM Subject: Re: [teres] Bases and Vibration Folks, The black goo, made by 3M, that I've mentioned from time to time works quite nicely at the headshell, far better than blu-tack can. Blu-tack is more massive, but far less absorptive. A polymer coating meant for tool handles called Dip-It works wonders on tone arms. I like it better than arm "wraps". The combination of the two do wonders for a quiet background. Of the two, the goo is easily removable if you don't like it, the coating would be somewhat more difficult. Igor --- Steve Zettel wrote: > on 3/26/00 04:58, Ivan Anderson at ivan@win.co.nz > wrote: > > > Hi Steve, > > > Hi Ivan, > > > Ivan wrote, about my questions concering the > relative strength of chassis vs > > arm vibrations: > > > > Well yes, this type of information would be most > helpful... but there is no > > doubt that the headshell and arm are excited to a > significant degree, as > > witnessed by the change in reproduction character > accompanying a change in arm > > board. > > > I am going to do an experiment to check that out, > changing my existing > acrylic armboard to aluminum. My Oracle has been a > test bed of sorts for > some of our early Teres questions, might as well > continue. > > > However the isolation from external vibration > requires an entirely different > > approach from that needed to absorb and dissipate > internal vibration, and is > > altogether easier to achieve. I can find few > studies into the dissipation of > > the frequency range we need to deal with, but > there are any number dealing > > with the isolation of equipment. > > > Yes indeed. Visiting the Soundown and EAR sites, as > well as any number > addressing resilient mounts proved that to be the > case. > > > Isolation is best achieved (perhaps) by a two step > approach, the use of mass > > and broadly innert material to reject the greatest > band of frequency possible, > > and the damping of the narrow but vicious > fundamental that these materials > > inevitibly have. > > > The other tack would be to accept a greater range of > frequencies, but > hopefully at a lower (near or below audibility) > energy level. Damping could > be applied here, too, I suppose. > > >>> Ivan had also written earlier: > >>> > >>> IMO it is wise to deal with the high frequencies > first. Not only are these > >>> the frequencies that most affect the full > extension of stylus travel and > >>> musical clarity but lower frequencies are still > likely to be transmitted > >>> through the boundary and can be dealt with later > in the chain. > > >> Steve Z postulated in reply: > > >> Seems to make a case for dealing with the > vibrations at the cartridge and > >> headshell first, then the arm tube, then through > the bearing(s) into the > >> base, armboard, etc. At some point they are > attenuated enough to be below the > >> threshold of audibility. One would think. > >> > >> There is a very old trick of using a little > Blu-tack or similar at the > >> headshell or on the cartridge. . . > >> > >> Also tonearm wraps are favored by some. > >> > >> Of course, in a no-holds barred effort, maybe all > of these should be applied! > >> > >Ivan returned: > > > You are right of course, and some experimentation > is called for, however, the > > same considerations are required in this effort as > they are in base / armboard > > design. I imagine that Blu-tack and arm wrap > materials reflect high > > frequencies and alter the transmission properties > of the arm, for better or > > worse, who knows. > > Certainly, Blu-Tack between the cartridge and > headshell might reflect back > energy, but some appreciable amount of energy must > be getting absorbed and > disipated at/in the lossier substance. Ditto armwrap > on the surface of the > arm. After all, this is how extensional damping > works, and it has been > proven to work in industrial and military > applications. Besides, energy is > already being reflected back by the material-to-air > interface already. > > But I agree, besides lowering the energy content at > some range of > frequencies of the arm or headshell or whatever, no > doubt adding the damping > alters the transmission characteristics of the new > damping/base material > system. It doesn't alter the characteristics of the > base material though. > Aluminum is still aluminum, acrylic still acrylic. > > And I also agree, more experimentation is needed. I > plan to also check out > what happens when I add an arm wrap to my Rega > RB-300. One correspondent on > the Phonogram list reports great success with it. > > > > snip > > > >> Steve (in the nature of a question, not statement > of fact): > >> So material matching is one key, but so is > matching mass, and elasticity. > > > Ivan: > > Matching impedence is the goal, of the suitable > materials, judgements are made > > as to practicality, expense, appearance, smell, > etc. > > > >>Steve: > >> At what point to we go from being too massive to > too light? If we for a > >> minute assume an excellent decoupling of our > table from structure borne > >> vibrations (say, suspended by bungee cords), then > the lighter our structure > >> the more susceptible to excitation by acoustic > energy. Of course, we have a > >> built-in lower limit with a 3" thick acrylic > platter coupled by a close > >> tolerance bearing to our chassis! > >> > > After the point where it is just right :-) Both > too light and too massive > > cause the same problem, but we are talking > interfaces here. The system might > > comprise of layers of increasingly dense > materials, and further massive > > components aimed at isolation. > > This would seem to say that one I idea I had, for a > sandwiched construction > of aluminum plate outside, then Isodamp or Dynamat, > and a central core of > styrofoam is not as good an idea as going from outer > layers of aluminum to > denser and denser layers, ending up with a central > core of lead? > > > snip > > > >>Steve: > >> Like maybe a sandwich of two sheets of thin metal > (Al or SS) constraining > >> some Isodamp and perhaps a central core of > styrofoam? The outer surface, > >> except for mounting surfaces, covered with a thin > layer of damping? > >> > > Maybe, but remember while a thin layer of metal > may have a good impedence > > match in itself, as soon as you attach something > else to it you change its > > properties. > > If we don't place the damping between the two > aluminum (for instance) pieces > to be joined then at the interface we have as close > a match as possible. I > am not ignoring that you also mentioned matching > mass and elasticity of the > two materials, but I don't think we are going to > practically have a > chassis/armboard of the same mass as the > arm/headshell. And we would never > be able to apply damping in any case. All I see as > an alternative is as > gentle an impedance transformation from one part to > the other as we go from > component part to another. > === message truncated === __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com Subject: [teres] Off-Topic Where Stuff Goes Date: Mon, 27 Mar 2000 01:01:37 -0700 From: Thom Mackris / Joan Panzella, Thom Mackris / Joan Panzella To: Teres_List All of this talk about how to best sink vibration reminds me of the a comment that Edith Bunker made in the old sitcom "All in the Family". In her typical lame-brained manner, Edith came up with a question whose implications are mind boggling: "How does the water know that it's kitchen water and not bathroom water?" Thom Subject: Re: [teres] Teres-Bearing & Platter - Progress Report Date: Mon, 27 Mar 2000 04:55:43 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com Well said, Steve! Igor --- Steve Zettel wrote: My > hypothesis is that a rigid, > inert material as chassis will intrude less on the > musical information we > are trying to retreive intact than a rigid, metallic > structure. > > I have absolutely no issue with you or anyone > opening a discussion based on > logic. I do have a penchant for challenging > assertations that do not seem to > be adequately supported by physical evidence. That > is all. > > Jon, please don't confuse an attack on an argument > as an attack on yourself. > > This rigid loop stuff may indeed work very, very > well. And I think it will > work even better when it is implemented with inert > material that does not > support or transmit energy as readily as metallic > substances do. > >>> > >> Shun Mook, I always say. This is great anecdotal > evidence but still no proof > >> that rigid and transmissive and damped after the > fact is somehow better than > >> rigid and non-transmissive, damped or not. My hypothesis is that a rigid, inert material as chassis will intrude less on the musical information we are trying to retreive intact than a rigid, metallic structure. I have absolutely no issue with you or anyone opening a discussion based on logic. I do have a penchant for challenging assertations that do not seem to be adequately supported by physical evidence. Jon, please don't confuse an attack on an argument as an attack on yourself.We are all trying to arrive at that most elusive of goals, "the Truth". This rigid loop stuff may indeed work very, very well. And I think it will work even better when it is implemented with inert material that does not support or transmit energy as readily as metallic substances do. Why would I want a fundamental resonance ANYWHERE within the passband of my system, or anywhere where it might intermodulate with the information I AM trying to retrieve? I don't want it at 250HZ and I don't want it higher, either! How are we dealing with it effectively at this higher frequency? I would welcome any information based in fact comparing the results of rigid coupling vs. dampened coupling vs "impedance coupling" (and an explanation of what impedance coupling is). > > At least your notion of a stiff, carbon fiber chassis is a *significant* > improvement...I'll give you that. Why thank you, Jon. I thought it a significant improvement too. Faint praise, but better than nothing. __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com Subject: Re: [teres] Teres-Bearing & Platter - Progress Date: Mon, 27 Mar 2000 05:08:55 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com Thank you for the admission, Jon. And precisely what I tried to point out to you. Please try to be less inventive with your "science". It could mislead, and I am more concerned with that than the possibility of offending you, for which I pre-apologize. Igor > ....I failed to note that given the speed of sound through > say, alloy being what it is, an approximately > foot-and-a-half long aluminum loop between stylus and > spindle is of insufficient length to develop even one full > wavelength at 10kHz, making the notion of out-of-phase > "feedback" at frequencies lower than that somewhat less > exact. I once clumsily suggested that one might want "all > energy to appear everyplace" thus canceling it. > __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com Subject: RE: [teres] C37, Ennemoser, & Dead Horses Date: Mon, 27 Mar 2000 08:36:08 -0700 From: Schei, Kenneth, Schei, Kenneth To: 'teres@aiko.com' IMHO, damping modern automobile components to eliminate noise is a very elaborate science and art, as exemplified by the results of some of todays vehicles. I believe auto designers use a philosophy I've proposed - eliminate as much noise as possible, and make the remaining as beneign as possible. Ken Ken Schei, P.E. Project Engineer Antarctic Support Associates Email address: scheike@asa.org Phone: 303-643-0163 > -----Original Message----- > From: Nicholas McKinney [SMTP:nick@lambdacoustics.com] > Sent: Thursday, March 23, 2000 7:43 PM > To: teres@aiko.com > Subject: Re: [teres] C37, Ennemoser, & Dead Horses > > > Enemoser's C37 is intended to MOVE the resonances of whatever it's > applied > to > > to those of carbon at 37C, hence having them fall into the hearing > systems > > "filter notches"... > > (to which Tom said "poppycock") > > Toms description is pretty much dead on IMHO. I have played with all > sorts of > coatings, dampers, etc. and have yet to find a holy grail. While it might > do > something good, "moving" other object's resonances to a single > pre-determined > one (that of carbon) is pretty far fetched IMHO. Maybe if I apply enough > if it > to my car suspension, I can make the road noise sound better. > > Nick Subject: RE: [teres] Teres-Bearing & Platter - Progress Report Date: Mon, 27 Mar 2000 08:51:04 -0700 From: Schei, Kenneth, Schei, Kenneth To: 'teres@aiko.com' Correct me if I'm wrong, Jon, but my math tells me that if the feedback is 1/10th of a wavelength out of phase at 1KHz as you say, it would be completely out of phase at 10KHz. And at every wavelength in between it would be out of phase by a different amount. At 20KHz, it will be slightly off of completely out of phase, with disastrous higher-level distortions resulting from the mismatch. In my opinion, that's precisely why I want to sink the vibrations in a lossy system rather than feeding them back. Ken > -----Original Message----- > From: Jon Lane [SMTP:jhlane@email.msn.com] > Sent: Thursday, March 23, 2000 9:48 PM > To: teres@aiko.com > Subject: RE: [teres] Teres-Bearing & Platter - Progress Report > > One more point, Steve. When you said, > > > > What does Olson say about acoustic feedback or > > > transmitted energy at say, > > > 10,000Hz and up? > > ...I failed to note that given the speed of sound through > say, alloy being what it is, an approximately > foot-and-a-half long aluminum loop between stylus and > spindle is of insufficient length to develop even one full > wavelength at 10kHz, making the notion of out-of-phase > "feedback" at frequencies lower than that somewhat less > exact. I once clumsily suggested that one might want "all > energy to appear everyplace" thus canceling it. With an > average 1kHz input by the cartridge, our 18" metal loop > experiences less than a tenth of a wavelength at any one > time; the phase effectively appearing everywhere > instantaneously. Perhaps that's what I was trying to > intuit. > > All of this must assume that energy once sunk into the > enormous relative mass of a "conductive", > *critically-damped* chassis will be so attenuated it won't > be able to return to appreciably effect the input end of the > machine. Transmission is utterly pointless without > termination, as some would seem to overlook. > > Concerning the speed of sound in materials, perhaps our > physicists could generously ruminate for us over the > implications of V=sqrtB/p which includes B=bulk modulus of > elasticity and p=density, a couple of intimately related > variables...I think its time I retired again. > > Jon Lane > > Subject: RE: [teres] Teres-Bearing & Platter - Progress Date: Mon, 27 Mar 2000 09:06:40 -0700 From: Jon Lane, Jon Lane To: teres@aiko.com > Thank you for the admission, Jon. And precisely what > I tried to point out to you. Please try to be less > inventive with your "science". It could mislead, and > I am more concerned with that than the possibility of > offending you, for which I pre-apologize. > > Igor My remarks weren't an admission; you've pointed out nothing; the concept has benefited greatly in your absence from the input of those far more eloquent than I. This is just verbal opportunism on your part, Igor. I've always *asked* for constructive input and have *seen* positive responses - none from you, because you prefer to posture. You generate an air of bogus, I'm-the-father-of-science concern and thusly talk down to others about your assumptions. Try and return my private correspondence if you're so "concerned" and can't hold your tongue. Jon Lane Subject: RE: [teres] Teres-Bearing & Platter - Progress Report Date: Mon, 27 Mar 2000 09:06:44 -0700 From: Jon Lane, Jon Lane To: teres@aiko.com > Correct me if I'm wrong, Jon, but my math tells > me that if the feedback is > 1/10th of a wavelength out of phase at 1KHz as > you say, it would be > completely out of phase at 10KHz. That comment was in reply to claims that energy was careening wildly about the chassis, indicating many iterations of each and every waveform. Had you suggested as much, Ken, or was that another poster? > And at every > wavelength in between it > would be out of phase by a different amount. Clearly, just as in your tonearm. Is your tonearm an optimized transmission line with a perfect termination? > At 20KHz, it will be slightly > off of completely out of phase, with disastrous > higher-level distortions > resulting from the mismatch. Disastrous. Hmmm. Why? Is our theoretical chassis undamped, Ken? Why would we do that when we've taken pains to indicate that critical damping is the goal? Had you missed those comments? And would any attenuation at all be performed even by an undamped conductive chassis? Have you heard a conductive chassis? > In my opinion, > that's precisely why I want to > sink the vibrations in a lossy system rather than > feeding them back. And if the lossy chassis has fundamentals far lower down than can't be corrected? Jon Lane Subject: RE: [teres] Bases and Vibration Date: Mon, 27 Mar 2000 09:21:28 -0700 From: Schei, Kenneth, Schei, Kenneth To: 'teres@aiko.com' Steve: I think that both you and Doug have hit on some excellent points. I fully agree with Doug in pointing out that the RIAA equilization requires the bass frequencies to be cut less deeply into the vinyl - that's the reason for the RIAA curve. I don't agree with pushing the noise into the higher frequencies for the same reason that you point out - brightness and other high frequency ugliness makes me run away with my hands over my ears. But that seems to be a personal thing; others seem to tolerate and even like high frequency response that I find grating. Ken > -----Original Message----- > From: Steve Zettel [SMTP:zettel@libby.org] > Sent: Friday, March 24, 2000 8:55 PM > To: teres@aiko.com > Subject: Re: [teres] Bases and Vibration > > on 3/24/00 20:36, Doug Kelly at kdouglas1@uswest.net wrote: > > > > > Well, probably only if we can push it high enough. Noise shaping in the > > digital world effectively does this - by adding a particular spectrum of > > dither, we decrease the noice in the mid band in exchange for much > > greater noise at the frequency extremes. Subjectively, this is a big > > win. I'm not sure that the materials we're talking about will allow us > > to push things much higher than the low midrange (big guess here, > > though), and I'd _really_ prefer to avoid coloration through the > > mids.... > > > Good things to think about, Jon, Thom, Chris, Doug. > > To me, colorations in the midrange seem very jarring, perhaps because so > much of the musical information is located there that anything that > doesn't > sound natural really sounds colored to me. We have a lot to compare to in > real life, or live music and perhaps that makes spotting artifical timber > easier. But, brightness, hardness or harshness in the highs will drive me > out of the room completely. > > It would be very interesting to see a vibration analysis of some turntable > designs to see just what frequencies and amplitudes exist with differing > construction. > > Steve Z Subject: RE: [teres] Teres-Bearing & Platter - Progress Report Date: Mon, 27 Mar 2000 10:45:33 -0700 From: Schei, Kenneth, Schei, Kenneth To: 'teres@aiko.com' Gordon: I have considered urethane mixed with graphite as well as common portland cement mixed with graphite or carbon. I think that carbon black is still available, and probably would be cost-effective. I've also considered common Portland cement which is rather bone-like chemically. Since you would be pouring the casting compound into an aluminum fabrication, a product with the correct expansion rate upon setting would be necessary. Many casting compounds shrink slightly upon setting which facilitates their removal from a mold but wouldn't be suitable because you wouldn't get a tight bond between the aluminum and the casting. A product that expanded too much might distort the aluminum fabrication. A grout product that expands only slightly probably would be most appropriate. Adding the carbon may also affect the expansion rate so experimentation would probably be a good idea. I wasn't thinking of pouring my casting into a metal fabrication so I wasn't too concerned about the expansion rate until now. I'll try to come up with more info in that area. Cheers, Ken > -----Original Message----- > From: MaughanAudio@aol.com [SMTP:MaughanAudio@aol.com] > Sent: Saturday, March 25, 2000 3:36 PM > To: teres@aiko.com > Subject: Re: [teres] Teres-Bearing & Platter - Progress Report > > << At 04:12 PM 3/23/2000 -0700, Schei, Kenneth wrote: > >Steve: > > > >We will never achieve zero extraneous vibrations at the stylus, although > we > >must strive to get as close as possible. (I believe that the lossy > approach > >comes the closest, but that's another arguement.) Since we can't > completely > >eliminate extraneous vibrations, we must also strive to make them as > benign > >as possible. Our old friend Ennemoser has theories on how to do that, > and I > >will consider them carefully when I build my TT base. Ennemoser > proposes > >that things that sound organic (like living bone) are the least > intrusive to > >our ears and are the easiest for our brain to filter out when necessary. > >That would lead me to believe that the signatures of stainless steel or > >other bell-like substances (even when damped) are more intrusive and > those > >materials should be avoided where possible. > > > >Cheers, Ken >> > Ken, I'd like your input on possible compounds to use as a poured > material. > My plan for the base presently consists of arms forming an "X" pattern > with > the bearing mount at the intersection. The top of this "X" pattern will be > at > least 1/2 aluminum. Sides will be constructed of 1/16# aluminum that will > be > welded to the top plate. Then inverting the whole assembly will show the > cavity of this "X" shaped structure that then will be poured with a > "resin" > material. I like the Ennemoser theories you have enlightened us with. > Since > aluminum is anti - Ennesmoser, that material must be countered with > Ennesmoser materials. What about urethane mixed with graphite (expensive)? > Or > an epoxy resin poured on top of graphite. Carbon such as activated > charcoal > would be a possibility to reduce costs. > Until Again, Gordon Subject: Re: [teres] Off-Topic Where Stuff Goes Date: Mon, 27 Mar 2000 11:44:29 -0700 From: Steve Zettel, Steve Zettel To: teres@aiko.com on 3/27/00 00:06, Thom Mackris / Joan Panzella at tmackris@earthlink.net wrote: > All of this talk about how to best sink vibration reminds me of the a > comment that Edith Bunker made in the old sitcom "All in the Family". > > In her typical lame-brained manner, Edith came up with a question whose > implications are mind boggling: > > "How does the water know that it's kitchen water and not bathroom water?" > > Thom > Wow, that is a stumper. . . no wonder plumbers get such high wages. In a related question, an environmentally concerned lady touring Libby Dam asked me if the water was different after we took the electricity out of it. She was rather belligerent and spoiling for a fight (most of the environmentalists are sure we are grinding fish into fishmeal in our turbines -- not to confuse them with the fact that the clearances are on the order of feet, and every species of fish stocked above the dam somehow appears as a thriving population downstream. . .) I assured her that we extracted the electricity in an environmentally safe way, and that the water remained chemically and physically unaltered and was probably safer to drink now that the deleterious effects of electricity had been removed. I didn't point out to her that she was standing in a magnetic field strong enough to spin a compass. . . Steve Z Subject: Re: [teres] Off-Topic Where Stuff Goes Date: Mon, 27 Mar 2000 13:48:32 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com Indeed, how *does* it know not to "appear everyplace all at the same time"? It would be good to realize that using materials that "tank", meaning store by echoing around, the energy is not the *only* way to draw it out of where you don't want it, even if that is *one* way, *if* implemented carefully enough . Igor --- Thom Mackris / Joan Panzella wrote: > All of this talk about how to best sink vibration > reminds me of the a > comment that Edith Bunker made in the old sitcom > "All in the Family". > > In her typical lame-brained manner, Edith came up > with a question whose > implications are mind boggling: > > "How does the water know that it's kitchen water and > not bathroom water?" > > Thom > > __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com Subject: Re: [teres] Bases and Vibration Date: Mon, 27 Mar 2000 14:12:09 -0700 From: Roscoe Primrose, Roscoe Primrose To: teres@aiko.com Igor Kuznetsoff wrote: > > Folks, > The black goo, made by 3M, that I've mentioned > from time to time works quite nicely at the headshell, > far better than blu-tack can. Is there a more accurate name for this so I can try some on other projects? 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] C37, Ennemoser, & Dead Horses Date: Mon, 27 Mar 2000 16:24:08 -0700 From: Schei, Kenneth, Schei, Kenneth To: 'teres@aiko.com' Thom: Bone, sea shells, teeth, ivory, Portland cement concrete, and common plaster are composed largely of calcium carbonate, CaCO3. I'm not sure I know why Ennemoser emphasizes the carbon more than the calcium; I think it's a combination of both. Thanks for pointing out that I think it's more important to make the structure of the right material rather than "painting it on." Even though I like some of Ennemoser's theories, I become wary when he wants to sell me something like his C37 paint, especially at "audiophile prices." I'd rather take his concepts and think them through myself. I have beliefs that may or may not transcend Ennemoser's; I believe that the nature of the structure is also important, in addition to the chemical composition. Bone has a porous interior with a thin, harder, contiguous outer shell of the same material. MDF has the same property. A concrete casting with a hand-rubbed shellac finish would be similar and could be very aesthetic. Other casting materials form a skin that is harder and less porous than the interior. I would seek those out. Laminating two completely dissimilar substances may not be the same, IMHO. I think BMW sought stiffness for handling purposes, not quietness. High performance autos often are much stiffer and also less quiet than the family sedan (if that exists any more in this day of Suburban Assault Vehicles :>)). I'm not sure why the "non-lossy" proponents think that lossy materials are more flexible and compliant than materials like aluminum or stainless steel; maybe I'm misinterpreting that. I wouldn't consider a base cast in concrete to be very flexible. Cheers, Ken > -----Original Message----- > From: Thom Mackris [SMTP:thom_mackris@yahoo.com] > Sent: Monday, March 27, 2000 2:17 PM > To: teres@aiko.com > Subject: Re: [teres] C37, Ennemoser, & Dead Horses > > Ken, > > Nick's was commenting that painting C37 on his car wouldn't quiet it down > - > something I know you don't advocate any more than he does. I know from > private conversation with you as well as your public posts that you are > looking for C37-like materials rather than merely merely expecting a thin > coating of some magic potion to shift the resonant spectrum of the base. > > That having been said, why does Ennemoser talk of Carbon-37 when bone is > primarily *calcium* ? > > One of the things that BMW did in the "3" series introduced in the early > 90's was to stiffen the heck out of the chassis. This really tightened up > the handling over the previous "3" series. It's my undeducated guess that > only *then* did they start to look at damping. I don't think they > considered an MDF chassis :-)) Is there a relationship between this and > tracking a record groove? Hmmm... > > Thom > > > ----- Original Message ----- > From: Schei, Kenneth > To: > Sent: Monday, March 27, 2000 7:39 AM > Subject: RE: [teres] C37, Ennemoser, & Dead Horses > > > IMHO, damping modern automobile components to eliminate noise is a very > elaborate science and art, as exemplified by the results of some of todays > vehicles. I believe auto designers use a philosophy I've proposed - > eliminate as much noise as possible, and make the remaining as beneign as > possible. > > Ken > > Ken Schei, P.E. > Project Engineer > Antarctic Support Associates > Email address: scheike@asa.org > Phone: 303-643-0163 > > > > -----Original Message----- > > From: Nicholas McKinney [SMTP:nick@lambdacoustics.com] > > Sent: Thursday, March 23, 2000 7:43 PM > > To: teres@aiko.com > > Subject: Re: [teres] C37, Ennemoser, & Dead Horses > > > > > Enemoser's C37 is intended to MOVE the resonances of whatever it's > > applied > > to > > > to those of carbon at 37C, hence having them fall into the hearing > > systems > > > "filter notches"... > > > > (to which Tom said "poppycock") > > > > Toms description is pretty much dead on IMHO. I have played with all > > sorts of > > coatings, dampers, etc. and have yet to find a holy grail. While it > might > > do > > something good, "moving" other object's resonances to a single > > pre-determined > > one (that of carbon) is pretty far fetched IMHO. Maybe if I apply > enough > > if it > > to my car suspension, I can make the road noise sound better. > > > > Nick > > > __________________________________________________ > Do You Yahoo!? > Talk to your friends online with Yahoo! Messenger. > http://im.yahoo.com Subject: Re: [teres] Bases and Vibration Date: Mon, 27 Mar 2000 19:00:52 -0700 From: Thom Mackris, Thom Mackris To: teres@aiko.com Ken, I don't understand why you contend that your design will be dead but that a rigid metal structure cannot be damped adequately. What am I missing here? The last I checked, everything in the physical universe has a resonant frequency. I know that you're the structural engineer here (help ... Daus ... we need you ) and maybe I'm missing something. The optimal design will *balance* many conflicting parameters, amongst them are: (a) properly terminating the toneaarm so that the interface *accepts* vibrations (b) killing the vibrations accepted by the interface (c) maintaining a fixed relationship between both bearings (arm & main). Mike Lefevre is fond of saying that engineering is the fine art of doing many things adequately or words to that effect. I share your concern for out of phase waves modulating each other and creating all kinds of sonic nasties, but this would appear to be possible at any frequency. The following is a *question* and not a statement of fact: can't low frequencies modulate high frequencies just as easily as highs can modulate highs? If this is the case, then it would appear that you are setting up a straw man argument, Ken equating - a rigid, damped metal structure to an (evil) solid state, feedback laden electronic device and your MDF "Ennemoser friendly" structure to a single ended triode. I fail to see the relationship, but I certainly welcome all comments on the issue. Cheers, Thom ----- Original Message ----- From: Schei, Kenneth To: Sent: Monday, March 27, 2000 7:53 AM Subject: RE: [teres] Teres-Bearing & Platter - Progress Report Correct me if I'm wrong, Jon, but my math tells me that if the feedback is 1/10th of a wavelength out of phase at 1KHz as you say, it would be completely out of phase at 10KHz. And at every wavelength in between it would be out of phase by a different amount. At 20KHz, it will be slightly off of completely out of phase, with disastrous higher-level distortions resulting from the mismatch. In my opinion, that's precisely why I want to sink the vibrations in a lossy system rather than feeding them back. Ken __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com Subject: RE: [teres] Bases and Vibration Date: Mon, 27 Mar 2000 19:54:56 -0700 From: Jon Lane, Jon Lane To: teres@aiko.com Thom said, > The optimal design will *balance* many > conflicting parameters, amongst them > are: > > (a) properly terminating the tonearm so that the > interface *accepts* > vibrations > (b) killing the vibrations accepted by the interface > (c) maintaining a fixed relationship between both > bearings (arm & main). In a rare moment of clarity , I thought I saw the vague relationships in the balancing act called Teres: 1. Energy inputs in two categories: Internal and external. 2. Internal vibration is centered at (very roughly) 2-5kHz, the natural resonance of light assemblies like carts, arms, bearings, and the record weighted by RIAA EQ. 3. External input centered at the power mid-point of acoustic feedback and structural vibration, or perhaps a couple hundred Hz., in other words, definitely not weighted according to RIAA. 4. A rigid relationship between bearings, as you point out Thom, being essential to sonic focus. Bending interplay between the "halves" of the system injects energy and based on the masses and materials we have available for many of our planned chassis and platter, probably at a frequency unable to be corrected later. Thus, we seem to want to accomplish the following: 1. Externally isolate. Surround the entire affair in an environment of acoustic silence. Sandboxes, pneumatics, what have you. 2. Internally attenuate. A 3" plastic platter to sink the record; possibly a mechanical linkage to sink the arm, the arm already invariably attempting to sink the cart. Platter is already a perfect impedance match, fairly damped internally and freely suspended (isolated from chassis). The chassis must still be critically damped if it is designed to accept input from the only remaining internal generator: The arm. 3. Center the bandwidths of both events in innocuous ranges. Don't inadvertently tune any part of the machine to the frequencies it is most susceptible to unless you can ensure that you are also damping it perfectly in that range. Avoid a chassis with any chance to uncontrollably bend internally at frequencies prominent for external structural or acoustic vibration. If all of this is true, this subjective weighting of the elements seems to reveal: 1. Floating the playing assembly is a good thing because it isolates from the external environment. 2. Panels are out - they risk bending regardless of the material. Sandwiches are out - if they're lossily bonded, they store energy at their resulting resonant frequencies (plural), typically low enough to center them at the frequencies of external inputs. (If they are intimately bonded, they act like monolithic structures again and resume their ringing elsewhere anyway. And I request correction on this point because I do not know the physics.) Irregular, dense shapes are in assuming they are damped nearly perfectly and still allow the admittance/attenuation of *internal* inputs, internal inputs being highly destructive if left in the respective playing-end parts. Sounds like a heavy, dense but skeletal framework suspended in a encompassing damping material is the direction to go. But I'm guessing the damping isn't going to have to damp appreciably because the *internal* energy present is both relatively HF and significantly attenuated by mass. OTOH, floating this combo of frame and boundary layer is the only remaining design goal and the one that eliminates much of the acoustic feedback and structural influences on the player. Anyone? Jon Lane Subject: Re: [teres] Bases and Vibration Date: Mon, 27 Mar 2000 21:45:54 -0700 From: Thom Mackris / Joan Panzella, Thom Mackris / Joan Panzella To: teres@aiko.com Correct me if I'm wrong Igor, but the 3M stuff is called "stripcalk" (not stripcaulk), p/n 08578 Igor began this journey using the tar-like gasket compound sold at Radio Shack in small quantities for sealing antenna mounting areas. In quantities where you'd be damping the inside panels of a CD player, this is ridiculously expensive for our cheapskate tastes. He then sourced the same stuff at a *huge* relative discount through auto parts stores like Checker Auto, Pep Boys, etc. as a gasket for windshield installations. The stuff I found had a rectangular cross shape 1/2" x 3/4" in a length sufficient to go around a windshield (12-15 feet ?) for under $10.00. I believe the stuff Igor sourced was circular in cross section. It comes on a wax paper backing. He needed a thin version for a "secret" project whereupon after badgering enough folks at parts counters he turned that up :-)) I've used it to damp speaker frames with great success. Cheers, Thom ----- Original Message ----- From: Roscoe Primrose To: Sent: Monday, March 27, 2000 1:03 PM Subject: Re: [teres] Bases and Vibration Igor Kuznetsoff wrote: > > Folks, > The black goo, made by 3M, that I've mentioned > from time to time works quite nicely at the headshell, > far better than blu-tack can. Is there a more accurate name for this so I can try some on other projects? 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] C37, Ennemoser, & Dead Horses Date: Mon, 27 Mar 2000 21:57:23 -0700 From: Nicholas McKinney, Nicholas McKinney To: teres@aiko.com At 03:26 PM 3/27/00 -0700, you wrote: >I believe that the >nature of the structure is also important, in addition to the chemical >composition. Bone has a porous interior with a thin, harder, contiguous >outer shell of the same material. MDF has the same property. We use low mass grade MDF (35lbs per foot?) for a table top on the vacuum hold down system on the CNC router. This is 1/2" thick and 3 foot by 3 foot. With an 8 horse motor we pull enough of a vacuum through the entire MDF sheet that anything larger than 10 square inches isn't moving -at all-. I never knew MDF was so porous before seeing this. >I think BMW sought stiffness for handling purposes, not quietness. High >performance autos often are much stiffer and also less quiet than the family >sedan (if that exists any more in this day of Suburban Assault Vehicles >:>)). Alot of the quietness can be found in the compliance of the suspension bushings. Many true performance cars use nearly solid bushings (some are solid), most family cars use the softest rubber they can find. >I'm not sure why the "non-lossy" proponents think that lossy materials are >more flexible and compliant than materials like aluminum or stainless steel; >maybe I'm misinterpreting that. I wouldn't consider a base cast in concrete >to be very flexible. I would like to hear the speaker that could flex 2" Corian that is only 17" wide. I like the arguments for the higher frequency resonants, I never thought to include the RIAA curve. However, the Q of a metal resonance has to be really high I would think? How would one build an aluminum base, solid stock? Hello Alcoa, just send Jeremy the bill please. Nick Subject: Re: [teres] Bases and Vibration again...:P Date: Tue, 28 Mar 2000 00:40:49 -0700 From: Daus Studenberg, Daus Studenberg To: teres@aiko.com Hi everyone, Wow, things have been quite hectic here, but I had some free time and was thumbing through a vibration engineering handbook today. I was looking at the constrained layer damping section and they talked all about the stuff we have been discussing. What I found interesting was that the thicknesses have a huge effect on how effective the dampening will be. From what I read, here is there guide. Take three layers, h1,h2 and h3 with h3 being the middle constrained layer. Now for optimum dampening, follow these two equations: h2/h1=.1 h2=h3 Looking at the graphs they provided, this configuration allowed the most dampening. As far as material selection goes, I didn't have time to go into detail on that yet. I did notice that the internal damping of wood materials were MUCH higher than the metals. As I see it, MDF will be more than stiff with the 3"-5" thicknesses that many of us are considering. My application has no weight constraint, so I see MDF as the best material of rmy application. Now if I were going to go to a suspended chassis, that would be a different story! :) Speaking of suspended chassis, I think they are great, but my problem with them is that I wnat to use a heavy record clamp. This results in periodic readjustment of the suspended subchassis, which I think is inconvienient. Daus Subject: Re: [teres] Bases and Vibration Date: Tue, 28 Mar 2000 01:26:48 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com Strip-Calk #08578 is correct. I believe there are also a couple of slightly thicker sizes (this is about 1/8" thick) in adjacent part numbers, but I have found this size perfect for general use, until really large quantities are needed, at which point the windshield gasket/installation version (not quite identical in composition, but very close) is excellent. In this size, you can apply it liberally to parts like speaker baskets for cheap ( and it is *very * effective there- you'd swear that a cheap stamped steel basket was queter than some high quality cast ones after application!). Igor --- Thom Mackris / Joan Panzella wrote: > Correct me if I'm wrong Igor, but the 3M stuff is > called "stripcalk" (not > stripcaulk), p/n 08578 > > Igor began this journey using the tar-like gasket > compound sold at Radio > Shack in small quantities for sealing antenna > mounting areas. In quantities > where you'd be damping the inside panels of a CD > player, this is > ridiculously expensive for our cheapskate tastes. > > He then sourced the same stuff at a *huge* relative > discount through auto > parts stores like Checker Auto, Pep Boys, etc. as a > gasket for windshield > installations. The stuff I found had a rectangular > cross shape 1/2" x 3/4" > in a length sufficient to go around a windshield > (12-15 feet ?) for under > $10.00. I believe the stuff Igor sourced was > circular in cross section. It > comes on a wax paper backing. > > He needed a thin version for a "secret" project > whereupon after badgering > enough folks at parts counters he turned that up > :-)) > > I've used it to damp speaker frames with great > success. > > Cheers, > Thom > > > ----- Original Message ----- > From: Roscoe Primrose > To: > Sent: Monday, March 27, 2000 1:03 PM > Subject: Re: [teres] Bases and Vibration > > > Igor Kuznetsoff wrote: > > > > Folks, > > The black goo, made by 3M, that I've > mentioned > > from time to time works quite nicely at the > headshell, > > far better than blu-tack can. > > Is there a more accurate name for this so I can try > some on other > projects? > > 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 > > > __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com Subject: Re: [teres] Bases and Vibration Date: Tue, 28 Mar 2000 03:22:49 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com Strip-Calk by 3M #08578. Automotive jobbers (distributing houses, usually) carry this. You'll have to call around a bit, probably, as it doesn't seem to be stocked all that universally. A box of it was $20 something when last I bought it a few years ago. Fortunately, a box will go quite a long way. If you want to try just a little bit of a very closely related product (possibly even made by 3M, but distributed by Radio Shack), RS carries a thin 1/2" wide strip on a roll, albeit at a rather higher per ounce price. It is a black sticky substance meant for outdoor connection sealing. Igor --- Roscoe Primrose wrote: > Igor Kuznetsoff wrote: > > > > Folks, > > The black goo, made by 3M, that I've > mentioned > > from time to time works quite nicely at the > headshell, > > far better than blu-tack can. > > Is there a more accurate name for this so I can try > some on other > projects? > > 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 > __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com Subject: Igor's Current Base Interpretation Date: Tue, 28 Mar 2000 16:24:14 -0700 From: Thom Mackris, Thom Mackris To: Chris Brady CC: Thom Mackris (h) Chris - sent privately. Notice the path to ground from the arm. Cheers, Thom --------------------------------------------------------------------- Name: Igor_base.gif Igor_base.gif Type: GIF Image (image/gif) Encoding: base64 Subject: RE: [teres] Bases and Vibration Date: Tue, 28 Mar 2000 17:15:13 -0700 From: Schei, Kenneth, Schei, Kenneth To: 'teres@aiko.com' Thom: Thanks for the interesting and provocative thoughts about Zen and Taoism and their relationships to quantum physics. I couldn't help but to pull your leg, but I do have a healthy respect for and interest in the Eastern ways of thinking, from which we can learn much. Regarding quantum physics, I am uncertain about Heisenberg's Principle, and Schroedinger's Cat may or may not be a dead issue. :>) I don't know about the entire universe, but the Teres thread has definitely been alive and pulsing with energy and information. Even though I am on one side of the fence, all sides of the fence (is that quantum mechanics at work?) have been informative and stimulating. I can't wait to see how our TT base debate takes off into the realm of quantum physics. Cheers, Ken -----Original Message----- > From: Thom Mackris [SMTP:thom_mackris@yahoo.com] > Sent: Tuesday, March 28, 2000 3:03 PM > To: teres@aiko.com > Subject: Re: [teres] Bases and Vibration > > Ken, > > While Zen is a state of mind, it is achieved through an innate > understanding > (or "aha experience") of the natural order of things - the watercourse > way. > I'm far more familiar with the principles of Taoism than with Zen, but > much > of the philosophy overlaps. All of this Eastern thought blends with > particle physics, of course. Those with a more solid grounding in quantum > physics can state this more eloquently than I can, but in my world view > the > entire universe is alive, and pulsing with *energy* and *information*. > > Our favorite pop author in this area of endeavor, Depak Chopra contends > that > a thought is nothing but an impulse of *energy* and *information*. It is > only in our anthropomorphic egocentricity that we associate a thought with > a > linguistic event. > > That having been said, what are the quantum implications of our design? > So > far, we've restricted ourselves to Newtonian considerations :-)) > > I have to repeat myself here, that I'm not interested in something that > rings like a bell & certainly the search for something to ground the > energy > is under way. If my thinking gets too complex, I may start with a simple > layer of acrylic which will serve for future comparisons. > > With respect to Rega saying that you shouldn't tignten down the arm nut - > I > am at a total loss(ey). Perhaps it is their experience with their MDF > bases > that it works best that way. Maybe you need to isolate the arm from all > of > those "boingey-woingey" resonances in their MDF bases :-)) This flies in > the face of all of Rega's and all of the other Brittish & Scottish arm > manufacturers' advice - rigidity at all costs - no removable headshell. > Take no prisoners. Beats me & fortunately, we'll have lot's of different > interpretations to compare in the next few months. > > Cheers, > Thom > > > Original Message ----- > From: Schei, Kenneth > To: > Sent: Tuesday, March 28, 2000 10:57 AM > Subject: RE: [teres] Bases and Vibration > > > Thom: > > My occidental understanding of Zen is that it is the achievement of a > state > of mind. I don't believe that inanimate objects, being mindless, can > achieve a state of mind. Actually, I know what you're saying, but I > couldn't resist. :>) > > You seem to want the metal for two reasons. One, you want metal rigidity > to > maintain Porsche-like control of the stylus in the groove, and second, you > also want metal rigidity to "embrace" the unwanted vibrations before > dissipating them. As we've discussed before, I'm not convinced that a > metal > base will control the stylus any better than MDF or concrete or Corian, > being a headshell, tonearm, bearings, and tonearm pedestal away, with all > of > the flexibility in between. But I certainly could be wrong about that. > However, Rega states that their tone arm sounds better if it isn't > tightened > down too tightly, which seems to be contrary to the metal base theory. > And > I don't know why I would want to embrace (e.g. amplify?) the unwanted > vibrations before dissipating them, rather than dissipating them straight > away, without reflecting and conducting them to unwanted places or raising > their frequencies. I'm not convinced about the heat sink grease analogy. > > Cheers, Ken > > > -----Original Message----- > > From: Thom Mackris [SMTP:thom_mackris@yahoo.com] > > Sent: Tuesday, March 28, 2000 9:26 AM > > To: teres@aiko.com > > Subject: Re: [teres] Bases and Vibration > > > > Ken, > > > > Why start with a ringing substance in the first place? To which I > replied > > .. The optimal design will *balance* many conflicting parameters, > amongst > > them ...... ". I'm not claiming any expertise in where this balance > point > > lies, but at the same time I'm holding firmly to Mike Lefevre's credo > that > > engineering is the art of doing many things *adequately*. I'm in search > > of > > a balanced design, and like you, any midrange or treble nasties will > also > > drive me out of the room screaming. > > > > In our discussion about autos, the focus was on damping and quiet, but > the > > analogy goes further. A performance automobile must negotiate twisty > > curves > > and potholes much as a stylus must negotiate a record groove. This > > "handling" design parameter is generaly in conflict with making a quiet > > car. > > It is next to impossible to design a cushy car which negotiates a > mountain > > pass with the aplomb of a Bimmer or a Porsche. In our 'tables we need > > *both* quiet, *and* handling, and this is where my stance of doing many > > things adequately comes from. > > > > I don't think Jon was equating a rigid structure to a feedback laden > > device > > any more than he was equating any *other* material with this character. > > My > > interpretation was that he and Ivan are in recognition of the fact that > > everything in the physical universe resonates. Jon and Ivan are > > approaching this problem by equating a rigid, metal top plate with heat > > sink > > grease that you might place between a microprosser and the actual heat > > sink. > > (metal top plate = heat sink grease, damping layer = heat sink). > > > > This is a very Zen-like concept of first embracing the vibration and > then > > dissipating it. Maybe we should call this approach "one hand clapping". > > > > The beauty of removable bearings is that we can indeed try both methods > as > > well as hybrids fairly easily and cheaply. > > > > Cheers, > > Thom > > > > ----- Original Message ----- > > From: Schei, Kenneth > > To: > > Sent: Tuesday, March 28, 2000 8:04 AM > > Subject: RE: [teres] Bases and Vibration > > > > > > Thom: > > > > I agree that a rigid metal structure can be damped, but why start with a > > ringing substance in the first place? That being a rhetorical question, > > I'll answer it as I understand the arguement and then let others correct > > me: > > Because the "non-lossy" proponents seem to think that a ringing > substance > > will somehow suck the extraneous vibrations away from the source to > allow > > them to be damped elsewhere. I've searched my limited knowledge of the > > subject and fail to understand that arguement or the advantages of it. > If > > rigidity is important (and it is), I believe that adequate rigidity can > be > > obtained from multiple layers of MDF, or from a concrete or carbon-laden > > epoxy casting. > > > > The only reason why I equated a rigid damped metal structure to a > > feedback-laden device is because that's how I understand Jon Lane's > > explanation of how it works. I think we have a multi-layered debate > here: > > 1) Whether one method is better sounding than another; and 2) Why the > > various methods work the way they do. One method may work better than > > another, but the explanations may be all wrong. The first layer is the > > most > > important to me, but often can only be verified empirically. Due to the > > nature of email and where we're at, we are presently focussing on the > > second > > layer, which is fun and stimulating, but may be tilting at windmills a > > bit. > > > > Cheers, Ken > > > > > -----Original Message----- > > > From: Thom Mackris [SMTP:thom_mackris@yahoo.com] > > > Sent: Monday, March 27, 2000 6:02 PM > > > To: teres@aiko.com > > > Subject: Re: [teres] Bases and Vibration > > > > > > Ken, > > > > > > I don't understand why you contend that your design will be dead but > > that > > > a > > > rigid metal structure cannot be damped adequately. What am I missing > > > here? > > > The last I checked, everything in the physical universe has a resonant > > > frequency. I know that you're the structural engineer here (help ... > > Daus > > > ... we need you ) and maybe I'm missing something. > > > > > > The optimal design will *balance* many conflicting parameters, amongst > > > them > > > are: > > > > > > (a) properly terminating the toneaarm so that the interface *accepts* > > > vibrations > > > (b) killing the vibrations accepted by the interface > > > (c) maintaining a fixed relationship between both bearings (arm & > main). > > > > > > Mike Lefevre is fond of saying that engineering is the fine art of > doing > > > many things adequately or words to that effect. > > > > > > I share your concern for out of phase waves modulating each other and > > > creating all kinds of sonic nasties, but this would appear to be > > possible > > > at > > > any frequency. > > > > > > The following is a *question* and not a statement of fact: can't low > > > frequencies modulate high frequencies just as easily as highs can > > modulate > > > highs? If this is the case, then it would appear that you are setting > > up > > > a > > > straw man argument, Ken equating - a rigid, damped metal structure to > an > > > (evil) solid state, feedback laden electronic device and your MDF > > > "Ennemoser > > > friendly" structure to a single ended triode. I fail to see the > > > relationship, but I certainly welcome all comments on the issue. > > > > > > Cheers, > > > Thom > > > > > > > > > ----- Original Message ----- > > > From: Schei, Kenneth > > > To: > > > Sent: Monday, March 27, 2000 7:53 AM > > > Subject: RE: [teres] Teres-Bearing & Platter - Progress Report > > > > > > > > > Correct me if I'm wrong, Jon, but my math tells me that if the > feedback > > is > > > 1/10th of a wavelength out of phase at 1KHz as you say, it would be > > > completely out of phase at 10KHz. And at every wavelength in between > it > > > would be out of phase by a different amount. At 20KHz, it will be > > > slightly > > > off of completely out of phase, with disastrous higher-level > distortions > > > resulting from the mismatch. In my opinion, that's precisely why I > want > > > to > > > sink the vibrations in a lossy system rather than feeding them back. > > > > > > Ken > > > > > > > > > > > > __________________________________________________ > > > Do You Yahoo!? > > > Talk to your friends online with Yahoo! Messenger. > > > http://im.yahoo.com > > > > > > __________________________________________________ > > Do You Yahoo!? > > Talk to your friends online with Yahoo! Messenger. > > http://im.yahoo.com > > > __________________________________________________ > Do You Yahoo!? > Talk to your friends online with Yahoo! Messenger. > http://im.yahoo.com Subject: Re: [teres] Bases and Vibration Date: Tue, 28 Mar 2000 17:57:40 -0700 From: Thom Mackris, Thom Mackris To: teres@aiko.com Reminds me of a bumper sticker I once saw .. "Heisenberg was wrong ... I think" :-))) ----- Original Message ----- From: Schei, Kenneth To: Sent: Tuesday, March 28, 2000 4:04 PM Subject: RE: [teres] Bases and Vibration Thom: Thanks for the interesting and provocative thoughts about Zen and Taoism and their relationships to quantum physics. I couldn't help but to pull your leg, but I do have a healthy respect for and interest in the Eastern ways of thinking, from which we can learn much. Regarding quantum physics, I am uncertain about Heisenberg's Principle, and Schroedinger's Cat may or may not be a dead issue. :>) I don't know about the entire universe, but the Teres thread has definitely been alive and pulsing with energy and information. Even though I am on one side of the fence, all sides of the fence (is that quantum mechanics at work?) have been informative and stimulating. I can't wait to see how our TT base debate takes off into the realm of quantum physics. Cheers, Ken -----Original Message----- > From: Thom Mackris [SMTP:thom_mackris@yahoo.com] > Sent: Tuesday, March 28, 2000 3:03 PM > To: teres@aiko.com > Subject: Re: [teres] Bases and Vibration > > Ken, > > While Zen is a state of mind, it is achieved through an innate > understanding > (or "aha experience") of the natural order of things - the watercourse > way. > I'm far more familiar with the principles of Taoism than with Zen, but > much > of the philosophy overlaps. All of this Eastern thought blends with > particle physics, of course. Those with a more solid grounding in quantum > physics can state this more eloquently than I can, but in my world view > the > entire universe is alive, and pulsing with *energy* and *information*. > > Our favorite pop author in this area of endeavor, Depak Chopra contends > that > a thought is nothing but an impulse of *energy* and *information*. It is > only in our anthropomorphic egocentricity that we associate a thought with > a > linguistic event. > > That having been said, what are the quantum implications of our design? > So > far, we've restricted ourselves to Newtonian considerations :-)) > > I have to repeat myself here, that I'm not interested in something that > rings like a bell & certainly the search for something to ground the > energy > is under way. If my thinking gets too complex, I may start with a simple > layer of acrylic which will serve for future comparisons. > > With respect to Rega saying that you shouldn't tignten down the arm nut - > I > am at a total loss(ey). Perhaps it is their experience with their MDF > bases > that it works best that way. Maybe you need to isolate the arm from all > of > those "boingey-woingey" resonances in their MDF bases :-)) This flies in > the face of all of Rega's and all of the other Brittish & Scottish arm > manufacturers' advice - rigidity at all costs - no removable headshell. > Take no prisoners. Beats me & fortunately, we'll have lot's of different > interpretations to compare in the next few months. > > Cheers, > Thom > > > Original Message ----- > From: Schei, Kenneth > To: > Sent: Tuesday, March 28, 2000 10:57 AM > Subject: RE: [teres] Bases and Vibration > > > Thom: > > My occidental understanding of Zen is that it is the achievement of a > state > of mind. I don't believe that inanimate objects, being mindless, can > achieve a state of mind. Actually, I know what you're saying, but I > couldn't resist. :>) > > You seem to want the metal for two reasons. One, you want metal rigidity > to > maintain Porsche-like control of the stylus in the groove, and second, you > also want metal rigidity to "embrace" the unwanted vibrations before > dissipating them. As we've discussed before, I'm not convinced that a > metal > base will control the stylus any better than MDF or concrete or Corian, > being a headshell, tonearm, bearings, and tonearm pedestal away, with all > of > the flexibility in between. But I certainly could be wrong about that. > However, Rega states that their tone arm sounds better if it isn't > tightened > down too tightly, which seems to be contrary to the metal base theory. > And > I don't know why I would want to embrace (e.g. amplify?) the unwanted > vibrations before dissipating them, rather than dissipating them straight > away, without reflecting and conducting them to unwanted places or raising > their frequencies. I'm not convinced about the heat sink grease analogy. > > Cheers, Ken > > > -----Original Message----- > > From: Thom Mackris [SMTP:thom_mackris@yahoo.com] > > Sent: Tuesday, March 28, 2000 9:26 AM > > To: teres@aiko.com > > Subject: Re: [teres] Bases and Vibration > > > > Ken, > > > > Why start with a ringing substance in the first place? To which I > replied > > .. The optimal design will *balance* many conflicting parameters, > amongst > > them ...... ". I'm not claiming any expertise in where this balance > point > > lies, but at the same time I'm holding firmly to Mike Lefevre's credo > that > > engineering is the art of doing many things *adequately*. I'm in search > > of > > a balanced design, and like you, any midrange or treble nasties will > also > > drive me out of the room screaming. > > > > In our discussion about autos, the focus was on damping and quiet, but > the > > analogy goes further. A performance automobile must negotiate twisty > > curves > > and potholes much as a stylus must negotiate a record groove. This > > "handling" design parameter is generaly in conflict with making a quiet > > car. > > It is next to impossible to design a cushy car which negotiates a > mountain > > pass with the aplomb of a Bimmer or a Porsche. In our 'tables we need > > *both* quiet, *and* handling, and this is where my stance of doing many > > things adequately comes from. > > > > I don't think Jon was equating a rigid structure to a feedback laden > > device > > any more than he was equating any *other* material with this character. > > My > > interpretation was that he and Ivan are in recognition of the fact that > > everything in the physical universe resonates. Jon and Ivan are > > approaching this problem by equating a rigid, metal top plate with heat > > sink > > grease that you might place between a microprosser and the actual heat > > sink. > > (metal top plate = heat sink grease, damping layer = heat sink). > > > > This is a very Zen-like concept of first embracing the vibration and > then > > dissipating it. Maybe we should call this approach "one hand clapping". > > > > The beauty of removable bearings is that we can indeed try both methods > as > > well as hybrids fairly easily and cheaply. > > > > Cheers, > > Thom > > > > ----- Original Message ----- > > From: Schei, Kenneth > > To: > > Sent: Tuesday, March 28, 2000 8:04 AM > > Subject: RE: [teres] Bases and Vibration > > > > > > Thom: > > > > I agree that a rigid metal structure can be damped, but why start with a > > ringing substance in the first place? That being a rhetorical question, > > I'll answer it as I understand the arguement and then let others correct > > me: > > Because the "non-lossy" proponents seem to think that a ringing > substance > > will somehow suck the extraneous vibrations away from the source to > allow > > them to be damped elsewhere. I've searched my limited knowledge of the > > subject and fail to understand that arguement or the advantages of it. > If > > rigidity is important (and it is), I believe that adequate rigidity can > be > > obtained from multiple layers of MDF, or from a concrete or carbon-laden > > epoxy casting. > > > > The only reason why I equated a rigid damped metal structure to a > > feedback-laden device is because that's how I understand Jon Lane's > > explanation of how it works. I think we have a multi-layered debate > here: > > 1) Whether one method is better sounding than another; and 2) Why the > > various methods work the way they do. One method may work better than > > another, but the explanations may be all wrong. The first layer is the > > most > > important to me, but often can only be verified empirically. Due to the > > nature of email and where we're at, we are presently focussing on the > > second > > layer, which is fun and stimulating, but may be tilting at windmills a > > bit. > > > > Cheers, Ken > > > > > -----Original Message----- > > > From: Thom Mackris [SMTP:thom_mackris@yahoo.com] > > > Sent: Monday, March 27, 2000 6:02 PM > > > To: teres@aiko.com > > > Subject: Re: [teres] Bases and Vibration > > > > > > Ken, > > > > > > I don't understand why you contend that your design will be dead but > > that > > > a > > > rigid metal structure cannot be damped adequately. What am I missing > > > here? > > > The last I checked, everything in the physical universe has a resonant > > > frequency. I know that you're the structural engineer here (help ... > > Daus > > > ... we need you ) and maybe I'm missing something. > > > > > > The optimal design will *balance* many conflicting parameters, amongst > > > them > > > are: > > > > > > (a) properly terminating the toneaarm so that the interface *accepts* > > > vibrations > > > (b) killing the vibrations accepted by the interface > > > (c) maintaining a fixed relationship between both bearings (arm & > main). > > > > > > Mike Lefevre is fond of saying that engineering is the fine art of > doing > > > many things adequately or words to that effect. > > > > > > I share your concern for out of phase waves modulating each other and > > > creating all kinds of sonic nasties, but this would appear to be > > possible > > > at > > > any frequency. > > > > > > The following is a *question* and not a statement of fact: can't low > > > frequencies modulate high frequencies just as easily as highs can > > modulate > > > highs? If this is the case, then it would appear that you are setting > > up > > > a > > > straw man argument, Ken equating - a rigid, damped metal structure to > an > > > (evil) solid state, feedback laden electronic device and your MDF > > > "Ennemoser > > > friendly" structure to a single ended triode. I fail to see the > > > relationship, but I certainly welcome all comments on the issue. > > > > > > Cheers, > > > Thom > > > > > > > > > ----- Original Message ----- > > > From: Schei, Kenneth > > > To: > > > Sent: Monday, March 27, 2000 7:53 AM > > > Subject: RE: [teres] Teres-Bearing & Platter - Progress Report > > > > > > > > > Correct me if I'm wrong, Jon, but my math tells me that if the > feedback > > is > > > 1/10th of a wavelength out of phase at 1KHz as you say, it would be > > > completely out of phase at 10KHz. And at every wavelength in between > it > > > would be out of phase by a different amount. At 20KHz, it will be > > > slightly > > > off of completely out of phase, with disastrous higher-level > distortions > > > resulting from the mismatch. In my opinion, that's precisely why I > want > > > to > > > sink the vibrations in a lossy system rather than feeding them back. > > > > > > Ken > > > > > > > > > > > > __________________________________________________ > > > Do You Yahoo!? > > > Talk to your friends online with Yahoo! Messenger. > > > http://im.yahoo.com > > > > > > __________________________________________________ > > Do You Yahoo!? > > Talk to your friends online with Yahoo! Messenger. > > http://im.yahoo.com > > > __________________________________________________ > Do You Yahoo!? > Talk to your friends online with Yahoo! Messenger. > http://im.yahoo.com __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com Subject: Fw: [teres] Bases and Vibration Pete, I can't seem to post to the server. Could you.... Date: Wed, 29 Mar 2000 00:28:44 -0700 From: phclark, phclark To: Teres@aiko.com CC: mikeinchandler@home.com ----- Original Message ----- From: "Micheal Larosa" To: "phclark" Sent: Wednesday, March 29, 2000 12:21 AM Subject: Fw: [teres] Bases and Vibration Pete, I can't seem to post to the server. Could you.... > > ----- Original Message ----- > From: Micheal Larosa > To: > Sent: Tuesday, March 28, 2000 11:14 PM > Subject: Re: [teres] Bases and Vibration > > > > Hello all, > > I,ve been reading with interest all the dialogue regarding bases and > > materials. > > > > This got me to thinking.... > > When i worked in a ceramics shop as a moldmaker I used a substance similar > > to concrete known as "Hydrocal" for my master molds. This material cures > in > > a fashion very similar to plaster of paris, > > but is Quite a bit more dense and MUCH tougher. It is extremely "dead" > > sonically. and to top it all off can actually be molded into very complex > > shapes. > > > > Just something to consider. > > > > > > > > Subject: Re: [teres] Bases and Vibration again... Date: Wed, 29 Mar 2000 00:45:02 -0700 From: Daus Studenberg, Daus Studenberg To: teres@aiko.com Hi, I found the information in a Shock and Vibrations Control Handbook in the library. Unfortunately it is reference material, but any college library should have it. Looks like you found a good material. I wonder if it was is as strong MDF with all of the layers?? I can understand your concern about MDF being resonant, and I have noticed that too. If it wasn't too susceptible to vibrations, I would have just used a 1" thick MDF subchassis and forgotten about this whole constrained-bolted-Ennemoser-black-goo mess!!! :) However, the book was comparing steel-aluminum to MDF and the internal damping difference between the two is significant. Daus BTW, how would you compare sand filled vs/ lead lined walls?? I plan on building a dual EBS Shiva Subwoofer at the end of summer. Thanks > Hi Daus, All: > Where did you find this info ? . . . . I'd like to study it myself. > Wrt the business of MDF having high internal loss, this is emphatically > not my experience and I speak as one who spent better than a decade cracking > the problem of loudspeaker cabinet resonance. > During that time, I built it all, sand filled, tar damped, bitumen > loaded, lead lined, Baltic birch a la BBC, Formica laminated, > and on and on . . . . > I finally got fed up and found a source of extremely high density, 5mm > hardboard. This stuff always just a bit of the oil they lube the hot presses > used to make it penetrating into the surface so I had it sheet sanded both > sides with a 40 grit belt down to 4mm thickness. From there I bought some > EVA glue, note that this is NOT the PVA glue used in cabinet work. The EVA > is used for binding books because it sets up just a bit flexible and stays > that way. > We filled a 4 ft wide roller-type glue spreader with the glue and then > laminated 5 x 4mm, 48 x 96 sheets together in a 250 ton veneer press, one > that's capable of 100psi over a 48 x 96 area. We didn't squeeze that hard > because we didn't want to "starve" to glue joints. > That cured and done, the material was sanded down to 3/4" and worked > pretty much the way MDF is worked . . . and that is pretty much the end of > the similarity. > To evaluate a speaker box's performance one can use accelerometers, > stethoscopes, laser interferometry and or number of electromechanical > methods and while these work, they are any combination of slow, difficult, > uncertain and/or vastly expensive. > Since the best way to evaluate a speaker is by listening to it, it's > reasonable to apply the same procedure to its enclosure. All I've done for > years is to simply hunker down beside the box and reaching around to the > opposite side with one arm, sandwich the box between my hand and the side of > my head - "squirming" my ear onto a good seal so that I can listen to the > panel. > Doing this with a well braced box made from the laminate just described, > the sound is very attenuated, band limited (no top or bottom end in other > words) and VERY clear - no resonant character. > With MDF, the sound is MUCH louder and very muddied, with a sort > character that I can only describe as "boingy-woingy" - strongly resonant. > In fact this is the sort of sound I have heard from all the construction > methods mentioned above, the laminate being uniquely silent . . . . > Measuring in free space - 25 ft above the ground on a special lift I > built for the purpose - the frequency response reduces in level using the > lam by about 2dB over the 100 to 400Hz band with the greatest reduction at > about 200Hz. The upshot being that only 1dB of band-reject EQ in the > crossover is required to make the speaker/enclosure combination flat +/- > 1/2dB from 100Hz to 1kHz. . . . . . > > > Best regards, > Bill - PEARL, Inc. > > > > > > > > > > > > > > > > > > > > > Subject: Re: [teres] Bases and Vibration Date: Wed, 29 Mar 2000 21:45:10 -0700 From: MaughanAudio@aol.com, MaughanAudio@aol.com To: teres@aiko.com CC: almarj@uswestmail.net In a message dated 3/28/00 3:15:41 PM Mountain Standard Time, thom_mackris@yahoo.com writes: << That having been said, what are the quantum implications of our design? So far, we've restricted ourselves to Newtonian considerations :-)) >> Thom has pricked my attention on this one. Four issues I have been dealing with on the bass design are. 1) Ridgidity - The Newtonian aspect. 2) Structural shape - Newtonian, but it starts to diverge because of asthetics and the effect on the surrounding space. 3) Effect on electromagnetic fields - Quantum mechanics. Some may not consider this but a transducer that converts movement into micro-volts is going to be effected big time by electromagnetic fields. 4) Resonant signatures and dampning qualities. Newtonian and Quantum. I want to use materials that are diomagnetic (materials that have the property of a weaker internal magnetic flux then the surrounding space). Materials inline with Ennemoser's teachings (I bet they're diomagnetic in their pure state). All carbon compounds are diomagnetic and graphite is the most conductive carbon available. I was thinking of a structural support frame of aluminum for rigidity and then using a carbon impregnated resin for an internal filler. Good rigidity, dampning qualities, good resonate signatures, good effect on the surronding electromagnetic fields. One more point on diomagnetic materials: One main audible difference in standard electrograde pitch copper and the better pure coppers is pure copper is diomagnetic (silver also) but poorer grades have increasing levels of iron. Just a few iron molecules per million will change copper from being diomagnetic. I'm still assimulating information and appreciate the dialogue which continues to prompt ideas on how to acheive something beyound what I could ever purchase. Until Again, Gordon Subject: [teres] Possible source for cast stone bases Date: Thu, 30 Mar 2000 19:09:46 -0700 From: Jon Lane, Jon Lane To: Teres@Aiko.Com There is another resource for those interested in very low resonance turntable chassis. I spoke with Roy Johnson, materials engineer at Green Mountain Audio in Colorado Springs today. Roy's company makes speaker systems and custom speaker cabinets with an emphasis on low-vibration, cast marble panels. The materials and approach used at GMA seem particularly effective at reducing internal noise to a minimum and may be beneficial to 'table design as well. Roy seems to express an early affinity for the project from what info I was able to relate during our call. Apparently, cast marble of this type weighs 240# per square foot and may have similar properties to an industrial substance I once mentioned used for casting prototype tooling. I think the stuff can be worked with machine tools. Cosmetics are either included precast or may applied after the fact. I'd imagine that a stone-like look could be easily arranged. Shapes are, of course, almost unlimited, and any manner of mounting considerations for the platter bearing and tonearm area can be included. It sounds like Roy could be interested in applying his expertise to the project in the interest of making a short production of a final, agreed upon part for those going in this direction. He indicates that he would charge little or not at all for the design process. There is no current website or email, but contact info is: Roy Johnson Green Mountain Audio 111.S. 28th St. Colorado Springs CO 80904 If there is interest, perhaps a member of the project could arrange a contact. Jon Lane Subject: [teres] Constrained layer damping Date: Thu, 30 Mar 2000 19:44:16 -0700 From: Sellek, Grant (TSA), Sellek, Grant (TSA) To: 'teres@aiko.com' Thanks Daus, let me get this straight.... the constrained layer and the bottom layer are both 1/10th the thickness of the top layer? So if the top layer is 60mm of MDF, the other layers are 6mm, including the bottom layer of MDF, correct? That's a pretty floppy piece of wood, would it really work eg standing on cones? (or do we rest it on a flat bed, eg wood or sand..? which is impossible if the layers are bolted together, see my last paragraph) Or do we need to say triple the thickness of all layers? That's quite a plinth! Another question about CLD (constrained layer damping). Someone said the three layers have to be bolted or clamped together. Won't the bolts or clamps simply transmit any vibrations between top and bottom layers??? Grant Grant Sellek Adelaide, Australia grant.sellek@transport.sa.gov.au -----Original Message----- From: Daus Studenberg [mailto:daus@ufl.edu] Sent: Tuesday, 28 March 2000 6:30 pm To: teres@aiko.com Subject: Re: [teres] Bases and Vibration again... ...thumbing through a vibration engineering handbook today... From what I read, here is there guide. Take three layers, h1,h2 and h3 with h3 being the middle constrained layer. Now for optimum dampening, follow these two equations: h2/h1=.1 h2=h3 Subject: Re: [teres] Constrained layer damping Date: Thu, 30 Mar 2000 19:59:30 -0700 From: Kalman Rubinson, Kalman Rubinson To: 'teres@aiko.com' On Fri, 31 Mar 2000, Sellek, Grant (TSA) wrote: > Thanks Daus, let me get this straight.... the constrained layer and the > bottom layer are both 1/10th the thickness of the top layer? I found this curious, too. I guess this assumes that the materials are of similar density and that structural stiffness is otherwise determined. > Or do we need to say triple the thickness of all layers? That's quite a > plinth! Or use different materials! > Another question about CLD (constrained layer damping). Someone said the > three layers have to be bolted or clamped together. Won't the bolts or > clamps simply transmit any vibrations between top and bottom layers??? To a degree but one is concerned less with the transmission than with the loss of energy in the ensemble. I can vary that since my laminate has compliant elements and the bolts can adjust the compression. BTW, I ended up backing them off so they are not a component. Kal Subject: Re: [teres] Possible source for cast stone bases Date: Thu, 30 Mar 2000 20:03:17 -0700 From: steve brooks, steve brooks To: teres@aiko.com I for one am interested...this is sort of what I had in mind...I assume we are talking about something similar to the base of La Platine? Steve > It sounds like Roy could be interested in applying his > expertise to the project in the interest of making a short > production of a final, agreed upon part for those going in > this direction. He indicates that he would charge little or > not at all for the design process. There is no current > website or email, but contact info is: > > Roy Johnson > Green Mountain Audio > 111.S. 28th St. > Colorado Springs CO 80904 > > If there is interest, perhaps a member of the project could > arrange a contact. > > Jon Lane > > > > > Subject: Re: [teres] Bases and Vibration Date: Thu, 30 Mar 2000 20:52:41 -0700 From: MaughanAudio@aol.com, MaughanAudio@aol.com To: teres@aiko.com In a message dated 3/30/00 10:39:50 AM Mountain Standard Time, SCHEIKE@asa.org writes: << While we're on the subject of quantum implications, one theory advanced about why transistors don't sound as good as tubes is because transistors manipulate the signal at the quantum level (tunneling electrons, etc.) while vacuum tubes don't, or don't as much, and transistors somehow muck up the sound because of that. >> Ken, I''ve also speculated on this and have assumed that tubes with their partial vacuums allow more of a ballistic trajectory of electron flow. Furthermore the electrons being contained as an emissive "cloud" highly excited, ready are more ready to flow. Solid state components on the other hand are constrained within a crystalline matrix and therefore experience more of a scattering effect as electrons travel at much lower levels of energy. Since the scale of distance is so much smaller in solid state devices, I do think that this effect is minor. The major difference I surmise in sound quality with tubes is due to the higher voltage potentials that tube circuits operate. This higher voltage works to saturate the dielectric of the transmission media (wire) used in the signal path. Having a greater saturation of charge in the dielectric thus reduces the energy that will be used by a signal as it's potential changes. If the circuit is working near ground potential then the alternating signal will effectively have to charge and discharge the dielectric each time the signal's polarity changes. Two things have led me to this conclusion: 1) Signal path topology seems to be critical in solid state gear. It's easy to build a good sounding tube amps but difficult to do likewise with solid state. 2) The best sounding tube amps I have been exposed to have higher anode voltages then standard. This is not always true, but the exceptions are tube amps that again pay critical attention to topology and the passive components used to interface everything. Where the higher voltage amps I have been exposed to used a lot of Radio Shack grade test leads! Until Again, Gordon. Subject: Re: [teres] Bases and Vibration Date: Fri, 31 Mar 2000 00:30:10 -0700 From: Daus Studenberg, Daus Studenberg To: teres@aiko.com Hi everyone, I received a lot of questions on the formula that I posted. I found that handbook that I could check out and got it. However, I found a book called "Vibration Damping" by Nashif that pretty much addresses most of our questions. Such topics include the effects of multiple constrained layers, effectiveness of unconstrained layers, thicknesses and effects, combined effects of different materials, and especially temperature effects, etc... I found it interesting that the proper use/size of the right materials can dramatically improve the effectiveness of your damping while maintaining great rigidity. I will try to allocate some time this weekend to put together a "Vibration Damping" FAQ based on my reading from this book. I hope this will help clarify a lot of the discussion we have had on this topic. :) Daus Studenberg BTW, I kind of had a good feeling about that multiple layered HDF/EVA glue board that someone on this list mentioned. I did read that you get an increase in damping with multiple layers. I think this material may be great in the it may be the missing link between plexiglass and lead that I have been looking for. Thanks to whoever suggested it. I was wondering if that person could talk a little more about the thicknesses used and impressions on the mechnical properties of the material. Subject: Re: [teres] Constrained layer damping Date: Fri, 31 Mar 2000 09:44:16 -0700 From: Stanley Goudge, Stanley Goudge To: teres@aiko.com; 'teres@aiko.com' Kal, Looks like JPL uses a tuned CLD system simular to yours. Stan http://jpltrs.jpl.nasa.gov/1995/95-0265.pdf At 08:58 PM 3/30/2000 -0500, Kalman Rubinson wrote: >On Fri, 31 Mar 2000, Sellek, Grant (TSA) wrote: > >> Thanks Daus, let me get this straight.... the constrained layer and the >> bottom layer are both 1/10th the thickness of the top layer? > >I found this curious, too. I guess this assumes that the >materials are of similar density and that structural >stiffness is otherwise determined. > >> Or do we need to say triple the thickness of all layers? That's quite a >> plinth! > >Or use different materials! > >> Another question about CLD (constrained layer damping). Someone said the >> three layers have to be bolted or clamped together. Won't the bolts or >> clamps simply transmit any vibrations between top and bottom layers??? > >To a degree but one is concerned less with the transmission >than with the loss of energy in the ensemble. I can vary >that since my laminate has compliant elements and the bolts >can adjust the compression. BTW, I ended up backing them >off so they are not a component. > >Kal > Subject: Re: [teres] Possible source for cast stone bases Date: Fri, 31 Mar 2000 16:55:05 -0700 From: Stanley Goudge, Stanley Goudge To: teres@aiko.com; Teres@Aiko.Com Here is link to cast granite, check out the sample/info section. Stan http://www.rathbun.com/phili.html At 06:03 PM 3/30/2000 -0700, Jon Lane wrote: >There is another resource for those interested in very low >resonance turntable chassis. I spoke with Roy Johnson, >materials engineer at Green Mountain Audio in Colorado >Springs today. Roy's company makes speaker systems and >custom speaker cabinets with an emphasis on low-vibration, >cast marble panels. The materials and approach used at GMA >seem particularly effective at reducing internal noise to a >minimum and may be beneficial to 'table design as well. Roy >seems to express an early affinity for the project from what >info I was able to relate during our call. > >Apparently, cast marble of this type weighs 240# per square >foot and may have similar properties to an industrial >substance I once mentioned used for casting prototype >tooling. I think the stuff can be worked with machine >tools. Cosmetics are either included precast or may applied >after the fact. I'd imagine that a stone-like look could be >easily arranged. Shapes are, of course, almost unlimited, >and any manner of mounting considerations for the platter >bearing and tonearm area can be included. > >It sounds like Roy could be interested in applying his >expertise to the project in the interest of making a short >production of a final, agreed upon part for those going in >this direction. He indicates that he would charge little or >not at all for the design process. There is no current >website or email, but contact info is: > >Roy Johnson >Green Mountain Audio >111.S. 28th St. >Colorado Springs CO 80904 > >If there is interest, perhaps a member of the project could >arrange a contact. > >Jon Lane > Subject: Re: [teres] :VTA adjustment (not really) Date: Mon, 3 Apr 2000 12:34:27 -0700 From: Stanley Goudge, Stanley Goudge To: teres@aiko.com; teres@aiko.com Hey Igor, your reading my mind, guess I need some damping between the ears. A large tip toe(3.5" dia.x 5"L) emerged in gear oil or silicon and lead shot to sink vibes from the tonearm and platter bearing is my next experiment for the seismic detector. Haven't yet decided how to set this up, what size buck shot do you think is best? And not sure how to rigidly couple the two cones, but the tonearm and spindle bearing would bolt directly to the cones via a large center hole. My reasoning here is to sink vibrations away (90*) from each other and to provide a mass that can except this energy and detour it from the connecting elements. As I write I just thought I could press the cones (AL) into 1" connecting aluminum plate with holes lined with isodamp forming a stiff compliance. Stan At 10:21 AM 4/3/2000 -0700, Igor Kuznetsoff wrote: >Ivan, > The blades sound like a good idea, and should >work to transfer energy nicely. I intend to use a >sand/recycled rubber tire chips mix. Adding 20-40% >rubber chips to sand amplifies the internal damping >characteristic of the sand by scattering sound waves >traveling through it via the randomly irregular >surfaces of the shredded/sheared rubber. Breaking the >coherence of the traveling wavefronts serves to >improve the internal damping characteristics of the >sand. Chips of a 1/8-1/4" size seem to work best. >The fact that they are rubber doesn't hurt anything >either, and they are cheap. The big trick is to find >a recycler who will sell you just a bucketful or so. >The chips are used in a number of industrial >applications, and these people prefer to talk about >dump truck loads of this stuff. Be aware, should you >decide to experiment with this, that after the first >stage of shredding (this is what we want), the chips >are ground down further, to a shaving or coarse sand >like consistency, which does not appear to be as >effective, but, maybe it is a matter of experimenting >more with the proportion, as optimizing the effect of >the larger particles is to some extent in this >application. I have not fooled around with the finer >grind very much, as it did not seem to work as well on >the first try. > Perhaps you recall that I wrote a short post >dealing with the possible use of (graduated impedance) >tapered metal "sound sinks" embedded within the >chassis to sink noise from the bearing and arm, but >*not* connected to each other, in order to avoid >terminating noise to each other. I have considered >the possibilities of this further, and added, in the >drawing mentioned below, an oil/lead filled sink >pocket located within the chassis, between the bearing >and arm, to improve noise suppression, without >detracting from rigidity. I drew this with an >aluminum plate sink extending from the arm mount >assembly and terminating within the oil, with the end >free to vibrate in the oil. This much was just a >musing, and adds too much complication to the >assembly, which should sink nicely directly into the >sand, so I may not use that detail, but am seriously >considering incorporating the oil chamber concept. > BTW, I *do not* discourage pleasant, >constructive, to the point discourse ("brevity is the >better part of oration"). What I *do* object to is >edgy, unpleasant *floods* of propaganda serving to >convert one to another's viewpoint by discouraging >discourse through sheer volume, all under the veneer >of "fervor". When that happens, and the person at the >receiving end of the criticism, not discussion, finds >it preferrable to withdraw rather than support his own >views, because there is not enough time to "get into >it", default is forced by volume, not concept. I know >I am not alone in this view, it has been discussed >privately. Some topics do require space to cover, but >that is not what I am talking about. This is supposed >to be an open forum, and the issue in point is in >restraint of the spirit of free discourse, and I do >find that to be objectionable enough that I would >prefer to unsubscribe, despite the work I have put >into this project from the very beginning, rather than >be aggravated. There should be no need for such "go >for the throat" techniques, and I have not enjoyed my >own occasional intemperate responses to this goading, >and regret that those bystanding have had to endure >it, sorry. I *do* enjoy conceptual *exchange*. >Please, lets keep it to that. > > Igor > >--- Ivan Anderson wrote: >> >... I intend to ground both the arm and >> > bearing directly into a sand mix ( or whatever >> else I >> > choose to experiment with)... >> >> Yes Igor, >> >> This sounds like a very good idea. >> I thought I might first try a 'heat sink' type base, >> as I have >> mentioned, with the blades embedded in sand. The >> blades extending to >> incorporate the tone arm and motor, in order to >> maintain a fixed >> relationship between them, but the top plate being >> cut out between >> these units. Adding direct grounding of the bearing >> also, should >> enhance this idea, one way or the other. >> >> BTW in posting this message to the list, I am >> soliciting replies. But >> if you don't wish to... god knows that there are >> messages I should >> have responded to, but couldn't, being a single dad, >> studying >> pharmacology at Auckland University, and welding >> stainless steel in my >> spare time (ha!) to earn a few bucks, so that I can >> invest double the >> cash as the rest of the world towards realising my >> dream turntable. >> >> ;-) >> Ivan. >> >> >> >> ----- Original Message ----- >> From: "Igor Kuznetsoff" >> To: >> Sent: Monday, 3 April 2000 18:47 >> Subject: Re: [teres] :VTA adjustment >> >> >> > Peter, >> > As the largest difference between the >> > thickness of records is certainly less than .25", >> the >> > range would really be more dependent on >> preplanning >> > the range of allowable mat thickness, starting >> with >> > none at all. Your upper number should handle all >> > likelihoods, I would guess. I did not get as far >> as >> > working out any numbers, putting this aside until >> I >> > had dimensions to work with. On a 10" pivot, the >> arc >> > generated & overhang correction would indeed be >> very >> > small, possibly smaller than everyday cartridge >> > mounting inaccuracies. My initial thought on that >> was >> > simply to design enough range via elongated or >> > oversized slots into the VTA base (which in this >> case >> > would be the armboard as well)-to-chassis mounting >> > holes. This detail may not be as elegant as Kal's >> > nice looking dovetailed design, but would do the >> job. >> > Perhaps Kal, or someone who has worked out the >> numbers >> > already, could help out here. No shims would be >> > necessary for initial adjustment in my concept. >> > The idea of an assortment of mat sizes is >> > intriguing, but runs into the problem of what to >> use, >> > which is a big question in itself, and then >> further >> > runs into the problem of how to get it in an >> > assortment of sizes varying by only thousandths of >> an >> > inch, and that to spec. I do agree with you that >> > adding a remote is likely to be too much of a >> > complication, even if I really don't see its power >> > supply as much of a difficulty. The mechanical >> > linkage may be more of a cost problem. The >> problem of >> > where to stop with the temptation of mechanization >> > might be something to think about. The Velleman >> > system offers more than one control channel, which >> > then just begs that advantage be taken of that, so >> we >> > may as well try to activate the cueing lift >> remotely, >> > as well...Anyway, an intriguing dream, but, well, >> it >> > *is* possible...And the possibility of using a >> > position sensor to facilitate repeatable presets >> to >> > quick adjust for favorite record thicknesses... >> > But, back down to Earth, my idea >> involves >> > the use of a "U" shaped base with vertical >> slotting >> > inside (performing a similar function to Kal's >> > dovetail, only in vertical orientation) which >> would >> > locate/carry a (vertically) sliding arm mounting >> > block. The vertical location of that block would >> be >> > adjusted via the use of the aforementioned paired, >> > horizontally oriented, tapered slides set within >> the >> > base of the "U" shape, and pushing the sliding arm >> > mounting block up as necessary via compression by >> a >> > threaded screw (the part that motorization would >> be >> > applied to if a remote were to be added, possibly, >> > *weeeeeell* in the future..?..). The return is >> > handled by a simple strap made, most likely, out >> of a >> > section of EPDM rubber which can be cut from one >> of >> > those common heavy duty black strap-shaped bungee >> > cords, to avoid the use of springs. The EPDM >> rubber >> > is much quieter internally than any spring would >> be. >> > Or maybe some O rings, I haven't worked out that >> > detail completely yet. After adjustment, a pair >> of >> > set bolts located through the wings of the "U" >> base on >> > either side of the sliding arm mount block would >> > complete the lockdown/"tighten-up" quickly and >> > conveniently, if bolts not requiring tools are >> used. >> > These could be as simple and cheap as (a clunky) >> pair >> > of common bolts, or as elegant and ergonomic as >> custom >> > machined wing bolts with large lever shaped >> handles. >> > The height adjustment screw could be matched to >> these, >> > and simply replaced if and when motorization were >> > realized (, if ever). Or a vernier calibrated dial >> > could be mounted on the threaded shaft to >> facilitate >> > more easily repeated resetting & adjustment. >> > A matching extension could be made >> for >> > the bottom of the base, in order to carry >> mechanical >> > grounding of the arm through in a direct path, >> using >> > all one material, to whatever the TT system is >> sited >> > on . This may or may not be of interest to those >> who >> > are into the arm to platter direct vibration loop >> > design concept, unless they *also* want to ground >> the >> > noise somewhere. I intend to ground both the arm >> and >> > bearing directly into a sand mix ( or whatever >> else I >> > choose to experiment with), using a *rigid* but >> noise >> > suppressive chassis between the two, and this is >> *not* >> > an invitation for a 10,000 word attack upon my >> choice >> > of concepts. Do what you want, everybody, but >> have >> > respect for individual choices. I am confident of >> my >> > approach, and do not mind if I come out ahead on >> my >> > own. Or not, at the will of my muse. I do >> certainly >> > and absolutely know that *following* trends >> > accomplishes no advances, as one cannot lead by >> > following, and it is clear to me that my concepts, >> in >> > that regard, are not understood, as I never found >> the >> > time , *or clear space*, to explain them fully. >> Nor >> > will I at this point, it is not worth it to me, I >> > might as well "keep" something, and am far too >> short >> > of time now to get into it, knowing that I might >> have >> > to spend every waking minute of the following week >> > just to "defend" my ideas from one or two >> particularly >> >=== message truncated === > >__________________________________________________ >Do You Yahoo!? >Talk to your friends online with Yahoo! Messenger. >http://im.yahoo.com > Subject: [teres] Bases and Vibration Date: Wed, 5 Apr 2000 22:36:05 -0700 From: Chris Brady, Chris Brady To: teres@aiko.com 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. I don't especially want to be blasted, but if you think I am going into the weeds, then blast away. I would like to thank all of those who have provided so much interesting and useful information. There often was not agreement and there were even some harsh words. I understand that putting out this information took a toll on both time and emotions. But for many of us that were less qualified to comment it has been a tremendous learning experience. It has been great to be associated with such a talented group. THANKS! The web page: http://reality.sgi.com/cbrady/audio/teres/cbrady.html If anyone else would like to post their designs just let me know. I was thinking that it would be nice to create a page linked to the teres page to showcase both designs and finished tables for the group. Chris