Nude Turntable Project
Been out of pocket dealing with the remnants of Isaac. So sorry to hear about your phono stage, hopefully there will be a quick turnaround. I feel bad that it was my idea that caused your problem, for that I apoligize, although it sounds like you didn't attach the disc to the bottom. I could see that feedback would be multiplied by not being so. Maybe a constrained layer attached would have worked? No spare phono? I thought we all had one. |
Thanks Ecir38, It's not your fault.....it's my stupidity. I suspect that Stanwal and others are correct in the placement theory of my Victor in relation to the speaker/subwoofer/corner but I need my preamp back to test it out? A spare phono wouldn't work as the whole preamp with inbuilt phono-stage needs to be sent to the technician. I do have a spare preamp but......whilst in storage....the left channel stopped working so it has also gone to the technician! Additionally.....things have changed in my set-up. I now use fully balanced connections between pre and amps as well as balanced phono cables from all but 2 of my arms. The back-up preamp does not have any balanced inputs or outputs. You win some.......you lose some :-( |
"It is now possible for me to design a circular aluminium frame cut and welded out of 10mm thick flats into which I can just 'drop' the Victor." Be careful, Henry, that's what some of us call "a plinth". If you want to take the time to describe in greater detail the events surrounding your disaster, perhaps I can help. I have quite a bit of DIY experience. From what you wrote, I don't have a clear idea. Was the Cu180 placed UNDER the TT101 prior to the event? And what exactly was the "event"? A burst of very high level signal is a danger to speakers primarily; I would not expect it to damage a phono stage or other electronic devices. An alternative hypothesis is that something blew in the phono stage, which is what you heard as a burst of loud noise. Nothing to do with acoustic feedback. But I don't know all the facts. |
Lewm, My take from his description is that he unmuted the preamp when MC was selected with the volume up and a MM installed - hence this probably blew the phono stage. Now the feedback he referred to in the other thread could be any of physical, acoustic or electrical. We dont have enough info as you say. Physical - just put the TT on a rubber sponge and see if it changes the level of feedback, if so this suggests physical. Swap the TT's around and recheck. Electrical - could be earthing related or could be adverse reaction from combo of cartridge & 2.5 metres of Cardas litz, ie tuned circuit from those cartridges and cabling is upsetting the phono stage. |
Hi Lew, I agree.....speakers are normally the first thing to 'blow' with a sudden violent volume? I've had it happen to me and lost not only the tweeters....but also the midrange drivers! Because of the shock factor.....I'm a little confused about the exact sequence of events but because I was testing this 'feedback' loop with various different turntable supports (including rubber sponge etc)....I will describe the methods I followed:- 1. Turntable motor is not switched on 2. Preamp volume control is turned down 3. Mute button is 'on' 4. Acutex 420STR cartridge is placed on the record 5. Mute button is switched 'off' 6. Volume control is gently turned up until low volume of 'feedback' just begins 7. Without touching the volume again....the feedback increases itself until I hastily turn it down and engage 'mute' Now I had the MM gain input selected....not MC....and had the volume turned down as I described. Then I supported the copper Cu180 'plate' on spikes on the shelf and placed the Victor directly on the Cu180. I placed the 420STR on the record and hit the 'mute' and that's when an almighty noise erupted. It was a couple of seconds before I could hit the 'mute' to stop the noise. Now here's where my memory seems confused? I thought I repeated the testing of this feedback with the Victor on the Cu180 and the feedback loop at a lower volume whereupon I then returned the Victor to its original spiked support and then switched phono inputs to the Raven AC. It was then that I had no sound from the phono stage. I reconnected a tonearm from the Victor and confirmed no sound and tried it with my headphones as well. All other preamp inputs (tuner, CD, tape, AUX) were fine. Perhaps the fact that the 420STR is like a giant antenna (according to Chris and the Professor Timeltel).......the hunk of copper under the Victor, induced the feedback at a much lower volume level than otherwise? |
Question: "I placed the 420STR on the record and hit the 'mute' and that's when an almighty noise erupted." Is this step #5? You just placed the 420STR on the LP and then un-muted? I presume the tt was activated, platter was turning. Yes? Can you characterize the crescendo of "noise"? Was it low frequency, high frequency, etc? Was it like what one hears at, say, a rock concert where the sound man is trying to adjust the mike and one can get that obvious microphone feedback between the bass player's speaker and the microphone, a "screech"? Since your unit is already being repaired, I suppose all this is moot, but it might be a good idea to try to hash it out so the problem does not repeat itself, I guess. |
Henry, I see that you already started a separate thread to discuss the problem. Sorry for asking you to repeat yourself here. I will read what has already been asked and answered on the other thread. Almarg is a very knowledgeable and thoughtful guy, as are others who have responded on the other thread. |
The 'nacked truth' seems to be that there is no such a thing as a 'nacked TT'. The most of those we are talking about are made in Japan, while J.Carr explained that there is no equivalent in Japanese for 'our' expression 'plinth'. They use the expression 'base' instead so whatever one put under his 'nacked TT' is obviously a 'base'. Raul's claim to be the first who discovered the 'nacked truth' mentioned even 3 of those 'pneumatic' AT footers with obvious convinction that the expression 'plinth' has a very clear denotation while those huge pneumatic footers on which both his Denon's were 'footed' should be seen as a totally different animal. I am known as very fond of semantics but this 'subject' is actually about the relation between the language and the so called 'reality'. Besides without the notion of an 'base' one get confused regarding what is 'above' and what 'below' so some of us even used the copper mat to put not 'obove' the platter but under the 'nacked TT' with some strange results. Regards, |
Dear Nicola, I do think there is a qualitative difference between a real plinth (including the 3-legged skeletal one described by Henry) and using just footers of one kind or another under the bottom of the chassis proper (which by the way was never intended to support the weight of the entire object). I guess you know as well that "base" is a synonym for "plinth" in English. |
Dear Lew, First of all glad to see that you are well and even more so to see your contributions again. There are two competing theories of truth. One is the 'referential' the other based on 'meaning'. Say 'bachelor' means the same as 'unmarried man' or 'plinth' means the same as 'base'. This one is also called 'analityc'. The problem however is that we need the reference to the reality: there is no truth inside the language. Both are combined in Tarski's theory of truth which is based on quantification and conditions. Say: 'some man are young and bold'. 'Some' is an quantifier while 'young' and 'bold' are conditions which some persons need to satisfy in order to make such statements true. Even persons who have never heard about whatever theory of truth are obviously able to say: 'I know 3 of such persons'. This means that they understand what 'young' and 'bold' means but also that there are such persons in reality which they are able to recognise. In your 'meanings theory' no Japanese will be able to recognise any 'plinth' while we in the West would have no idea what 'base' is refering to. As a scientist you are supposed to believe in the 'universal truth'. The 'synonym' approach will not do as you can check by Quine or may conclude from my explanation. Regards, |
Lew, I agree that in theory if tonearm and platter are subject to the exact same vibrations then the stylus should not pick them up. In practice I don't see how it is possible. Vibration has to take a different path and go through different materials to reach different locations on a turntable. I would think that even if everything is rigidly coupled the vibration will be changed and possibly delayed in time depending on what it is traveling through. Is it even possible to design a turntable that would vibrate the same at the cartridge and at the platter at the same amplitude and phase from an outside stimulus? |
I would think that even if everything is rigidly coupled the vibration will be changed and possibly delayed in time depending on what it is traveling through. The designer of the Onedorf turntable (which uses a separate armpod) said the same thing when I rehearsed for him this (Lewm's) argument in favor of rigid coupling. Basically, as you say, the wildly differing shapes and materials of the tt motor and tonearm will prevent 'vibrating in harmony'. |
My turntable (JVC TT101) came with a plinth as a QL-10. Now it has no plinth so however you want to parse the language a large support was removed and now the TT sits on its tin-can of a base on cones. So I believe it is plinthless - nude or not. I am surprised Henry's phono pre blew rather than the preamp circuits - to me it would take a huge amount of signal from the cartridge to blow the phono side and with Henry's recollection of having it on MM there should have been enough headroom to hold this - otherwise dropping the needle onto a record will make a big enough boom to damage the phono circuit. |
IMO, the Onedof turntable was designed around a novel idea for a bearing. The designer seems to know very little else about turntable design. Thus I think he is entitled to his opinion but that it is not much more relevant than that of any other moderately knowledgeable person. Sorry. There are ways to couple the bearing and tonearm effectively. I do agree that the goal is a tricky one. In the process, you probably don't want to introduce tt motor vibrations. Nicola, I know you are having a good time with your philosophical meanderings, but really, base = plinth, in English. It's that simple. |
Dear Lew, I am sorry for you but I already mentioned Quine for 'çheckup':'The problem of meaning in linguistics' ( From a logical point of view). The identity relation between meanings make no sense as in your 'plinth=base'. Semantics and dictionary are different animals. Besides I also mentioned J.Carr who is, as far as I know, American and supposed to 'know' his English. He writes 'plinth' with quotation marks because the meaning of this word is not as 'clear' as one assume. If he thought that 'base=plinth' he would not state that in Japanese there is no word for 'plinth'. Dover's 'Emperors clothes' are more to my liking in the 'nacked' context than your 'theories' about the ' nude project'. Regards, |
Addendum, Remarks about someone's theory without any specification is of course weak. Well, dear Lew ,in your previous post you stated: 'there is qualitative difference between a real plinth (sic!) and ...just footers'. Considering that 'plinth=base' those 'footers' are neither of both and must be some objects of the 'third kind'. If there is difference than logicaly they can't be 'the same'. Not even qua 'meaning' (alias 'synonym') So to make your point you are forced to make distinction between 'plinth' (the 'real one')and other possible 'things' on which a TT can be put as base. But because my English is not adequate you must be right qua English . Regards, |
I am sure you are aware Nikola of the different meanings for the word nacked ? |
Dear Chris, I learned from Frege not to ask for the meaning of words but to think about the contribution a word makes to the meaning of the sentence in which it is used. The 'context' is one way to think about this question the other is the thought expressed. The meaning of a sentence is the thought expressed. Well the same thought can be expressed in different ways and this imply that we can express the same thought with different words. The fact that the science is universal pressupose recognition of the same thoughts in different languages. To be able to judge if some thought is true one of course need to understand the thought first. Considering the universal succes of science this probable means that there are no problems with understanding. So no wonder that 'new thoughts' in science are welcome no matter from which country or languge they come. Regards, |
Dear Nicola, Freud is widely quoted as having said, "Sometimes a cigar is just a cigar." If he said it, I don't know whether he said it in Viennese or English, but the meaning is left to the knowledgable listener to divine. A person who had no prior experience of Freud would miss the point entirely. Thus, among us guys, "plinth" means the same thing as "base". The argument is whether those footers constitute a legitimate base or plinth. Those 19th and early 20th century philosophes of whom you are so fond should have been watching more television. Someone in my early and mid-life used to remind me that Socrates was forced to drink Hemlock. |
Dear Lew, I assume that my legs or footers are 'legitimate' base to carry my nacked or clothed body. I can imagine that in some future time I may need an 'plinth' in the form of a wheelchair. This will , I also assume, make some 'qualitative difference', to use your own argument. BTW I thought that nobody care anymore about Freud. Anyway his dreams were probable in (Austrian) German. |
Addendum, the reason I think that Freud probale dreamed in Austrian German is that I was not able to understand the Austrians for the first 3 months . However I am sure that he wrote his teaching about the 'dream interpetation' (Traum deutung) in ordinary German because I was able to read his book. I had an fantastic relation with my parents with no problem of any kind till I learned abou Freud . I was stuned that this guy from Austria knew better than I myself what I thought about my dad and mom. Such is the force of the marker 'Dr' for someone's name not to mention the title Professor. Since Freud I never felt easy at home because of my feeling of quilt. I had no idea of what I was quilty but , you know, an Professor knows everything better. |
Hi Lawrence, Try this Link |
Hi Lawrence, Perhaps you can start HERE But there are questions and progress reports all the way through. |
I have said this before but will say it again. Thank u Henry for the inspiration behind your thread. Raul did mention Nude TT - in a couple of threads but we never did see a picture of his setup. I learned more about resonances and vibrations during this project than I would have, I feel in any other way. So if anyone is a little bit curious, adventurous and have a vintage DD go for it. My SPMKII project has been through many versions. It is still not encased in a wrap around plinth, but it is now bolted to rigidly to the base (plinth) below it with the solid SS legs. The armpod I feel due to the 19 lbs involved provides a solid enough footing. Still, since the tonearm is unlikely to change, my next version will probably have the SS legs shortened, so that the armpod can be bolted directly to the base (plinth) as well. Similar in a way to the Verdier. |
Thanks Lawrence, I appreciate your feedback. I certainly agree with you....especially in the case of analogue.......that the great turntables, tonearms and cartridges of the Golden Age of Vinyl (60s, 70s and 80s)....more than hold their own against the 'cost-no-object' modern versions. Imagine what might have been had R&D funds not dried up after the introduction of the CD? Re-reading what I wrote 2 years ago....I think an addendum is in order:- I upgraded the TT-81 to the TT-101 which was an audible improvement IMHO. I also purchased the Sutherland Timeline and by using the Victor TT-101 as a 'Benchmark'........I managed, by trialling different platter mats and different motor arrangements on the Raven AC.....to maximise the speed accuracy and neutrality of this belt-drive turntable so that it really is difficult for me to reliably 'pick' which deck I am listening to? This resulted in the removal of one of the three motors on the AC-3.....and the removal of any platter mat at all. The vinyl record is placed directly on the copper platter top-plate with a heavy brass record weight on top. The ability to directly compare two turntables and multiple tonearms is invaluable to improving the performance of one's system IMHO. Regards Henry |
Hi Chris, As always....I appreciate your response. I'm happy indeed if I helped in some small way for you to enjoy your wonderful system even more? I think your 19 lb arm-pod is both heavy and stable enough? What most people will surprised to learn is that the deflection (and movement) of the cantilevered outboard arm-boards of the big Micro turntables and the Raven AC.....is a magnitude greater than any differential movement in a reasonably thick common shelf on which a separate deck and arm-pods may be mounted. This can easily be demonstrated mathematically via structural analysis. Seeing that many audiophiles staunchly advocate the superiority of the big Micros over many SOTA new decks........I don't believe your concerns about a 'floating' armpod are warranted? :-) Regards Henry |
I don't believe your concerns about a 'floating' armpod are warranted? Hi Henry I have had this armpod for quite a while now. I am not concerned about floating. It hasnt moved. This has to do with resonance and vibrations. I will change their patterns if I change to a rigid directly coupled armpod. I want to hear this change. My SP10MKII is my PET project. Its role in my setup is all about learning from it. This cannot stop. Its the perfect candidate with the motor, bearing, spindle, platter so close to one another to learn more about resonances. My DD setup is very flexible by design, so I can experiment with little effort really. I have a spare set of SS legs from version 3 with the points the machinist will cut these and put threads in for me. The armpod has three threads for spiking or bolting. The bolts would come through the base (plinth) up into the armpod. No big deal. I want to see if I hear any differences. If I dont like it, the armpod can be converted to free standing anytime its reversible. No Risk , Nothing ventured, Nothing gained. Fwiw - I have probably hit the limits with the SP10MKII and that is ok too. To me like I say in Goldilocks and the three turntables on my system page. The SP10MKII sounds like it is just trying too hard to be accurate. I think it needs a little LESS CORRECTION if possible, and still be able to maintain STABILITY to make it better. Its a balance. Right now the correction piece is the Alpha. So if I have hit the limits with it. I am ok with that. Maybe one day I will pull off the cover underneath and have a look to see what can be done to better isolate what is in there. For what the setup cost $1500 - not including tonearm. I dont think it can be beat in that price range. What does $1500 buy you today. BTW I recommend still that you isolate your victor and the armpods on a separate shelf. There will be a definite audible change. Easy enough to experiment with a piece of material and three or four footers. Seeing that many audiophiles staunchly advocate the superiority of the big Micros over many SOTA new decks Henry - Not familiar with the Micros - but I can tell you my Verdier raised the bar high really high. Every day it amazes me more and more because I learn how to set it up better. I think this design has been around for a while too? Cheers |
Dear victor tt 101 owners: Mine is currently at a shop and I'd like to return the table to its original condition, but unfortunately previous owners seemed to have messed with it. In particular, 1: the bearing seal has been opened even though the manual asserts that it does not require lubrication. Since it has been compromised already, I'm looking to see what kind of lubrication I should use. Evidently, there is a distinction between grease and oil. Should I care? The guy who runs the kenwood l07d site says the best oil for that table is Redline pure synthetic 20 weight racing oil. Anyone care to offer an opinion on this? I literally don't know a single thing about this matter. I see, Aigenga, that you have opened up the bearing casing and used Mobil 1. Was there a reason for that choice? 2. In the service manual, it shows a round 'rubber sheet' (part 45_ that sits below the platter (surrounding the motor casing). Does everyone have that piece? Mine doesn't. If yours has it, can you do me a favor and measure the thickness. I'll try to rig something. Aigenga: you note above that you cut some 3m material to place under the platter (you linked to a pic of it). Did you replace the stock rubber sheet with the 3m? thanks. |
Hi Banquo, My TT-101 appears to be original and untampered with? HEREis a photo of the rubber sheet (part 45) glued to the underside of the platter. It appears to be approx. 1mm thick? Regards |
Banquo, I have the sheet under the platter as Halcro described. I also covered the entire interior of the chassis with the 3m product as I described along with the underside of the rim (which is how I describe the silver ring that the controls are on), and of course 80% of the tin can at the bottom. I couldn't be happier with that work. Another thing that I did more recently is to put steel/neoprene washers between the motor and the chassis. I realized that the chassis is actually a plinth of sorts as the motor and bearing are self-contained and supported by the chassis. So the table isn't really nude after all. The new washers replace a double layer of steel and copper washers that were there. Most TT motors that reside inside a plinth (both idlers and belts) are shock mounted, now mine is too. If anyone wants instructions on how to do this, let me know. Highly recommended. As for your open bearing area, no big deal - I recently reopened mine to measure the ball bearing so I can replace it with a ceramic ball (it is 4mm - considerably smaller than I remembered). I refilled it with Mobil One. I don't think it matters which synthetic oil you chose - any good one will run in a car engine for 10 - 15,000 miles without breaking down so a turntable won't ever effect it. My TT-101 is running better than ever. Starts right up from a long hiatus. Don't ask me why. Makes me smile. |
Thanks, Aigenga. I have EAR Isodamp (a 3m product) sheets on the way and I'll be following your lead. I know about those motor washers because one of them evidently 'escaped' and ended up stuck to the rotor, thus causing one of the problems with my turntable. I'm game to try these steel/neoprene washers. Where does one get these things? Regarding the bearing: how did you support the table while accessing the bearing? My platter was riding low so I had to adjust that big screw, but I had a devil of a time handling the turntable with screwdriver in hand. I can't imagine trying to clean the bearing and changing the oil w/o an extra pair of hands. |
Yes Banquo....it does indeed look my idea and I'm pleased someone did it. I need to get around to doing something myself....but my friendly metal-shop man has retired and I'm a bit loathe to 'tender' out the fabrication to some unknown operators? By the looks of things.....there appears to be a growing 'band' of 'nuded' Victor TT owners out there? It must sound good for this scale of 'adoption' :-) When you have time.....I would be interested to hear your thoughts on the differences between the TT-101 and the Technics SP10/II? Of course.....if the music is great.....you may not want to waste your time writing instead of listening? Enjoy. |
Dear Banquo363/Halcro: That's exactly what I did several years ago with my Denon's, I posted here and in the past in other threads. Difference was that I used natural marble and natural onyx stones ( beautiful look for say the least. ) all that supported for the AT 616 pneumatic footers. I still have those stone bases but are so big that I have no space to use it again with my Victor 71/Denon 80/75. Yes, it works fine. When I have some time I will test it again against the nude one in real time. Regards and enjoy the music, R. |
Dear Aigenga, Your listening is the final arbiter of whether any change is a good one, but I would only observe that by using a "spongy" washer where once was a solid washer, you have to some degree decoupled the motor from the rest of the chassis elements. This obviously can be a good thing. But it can also be a bad thing, because now the motor/bearing/platter as a unit are more free to move when the motor is called upon to increase torque in response to drag on the platter. Remember Newton's Laws of Motion: every action has an equal and opposite reaction. When the motor urges the platter in the clockwise direction, the motor itself has a tendency to move counter-clockwise. Plus, the Victor engineers had the option to anchor the motor assembly in any feasible way, and they chose what they chose. Just a thought. Irrelevant if you are pleased with your modification. |
Banquo, to handle the tt I remove the platter and turn it upside down on a large flat bowl that is covered with a dish towel. The washers are about 5/8" in diameter and 3/32" thick. They will raise your platter a tad by raising the entire motor. That gives you more leeway as to how tight that bearing thrust plate screw must be. Not tightening it too much is rather critical for clearance as well as proper alignment of the motor components. Lewm, the 1/16" neoprene bonded to 1/32" steel do not make for a spongy mount especially if they are torqued down. Your point is quite valid but my ears tell me this is better. Psychoacoustics no doubt but c'est la vie. Anyway the washers that JVC used, being two metals and thin are a pain in the ass. As Banquo found out (and I did too) they tend to get lost in the machine. Gary |
Naked.....not 'nude'! 5 months after mentioning my idea to Banquo.....about designing a 'cradle' out of stainless steel flats to 'drop' the TT-101 into......I finally got off my bum and did it. Designing is one thing......but drawing it and then finding people to quote and then waiting for the thing to be built....is quite another :-( The cradle is made from 4mm engineering Grade 316 stainless steel all laser cut and welded. I had thought to simply drop the whole TT in together with its flimsy black steel bottom perforated cover......but then I thought......why not go fully naked and avoid any possible resonances related to the cover panel? The result will not be to everyone's taste.....but to me it's more in line with my thoughts on the Copernican view of turntables whereby the tonearm pods are now correctly visually dominant surrounding the skeletal structure of the turntable. I suspect that someone like Lewm will find some way to interpret this 'cradle' as some kind of 'plinth'.......but what can I do? :-) How does it sound? A bit too early to file a report......but it is audibly changed. For the better of worse?.........stay tuned..... |
