Nude Turntable Project

heavy "weight bias" to the front left when viewed from the front

maybe its the front right side now that I think about ..... its been too long.

Chris.

Like your Alpha leg analogy. Actually, with the other two feet, we are trying to block energy transmission as much as possible although in practice I doubt that this can truly be done. The PVC feet are softer than the plinth and the shelf, acting like a road block.

I have tried this approach on all of my home brew and some commercial TT's, it doesn't seem to matter if there is weight asymmetry.( That said, my current triangular TT is virtually weight symmetrical) In all cases IMO, the one spike and two "feet" arrangement was better than 3 spikes. A trend is that, for a conventional plinth type TT, the spike goes close to where the tonearm is. I don't see any issue with energy build up in a suitably rigid, hard chassis.
The idea is to get mechanical energy out of the system quickly and cleanly.

Also I don't think that there would be any issue with this approach on an air or magnetically levitated platter.

No figures to back all of this up. Just listening.

Cheers.

08-26-13: Richardkrebs
From reading here it seems that those that prefer hard supports make them all out of the same material. I believe that this arrangement can be improved, if your goal is to wick energy out of the TT structure. By using, say, three identical hard feet you are creating multiple paths to the shelf (ground). This is the electrical equivalent of an earth loop.

This is certainly not new.
The seminal article for mechanical grounding in audio equipment as applied to turntables was the Technical Report by Martin Colloms of the Goldmund Reference published in Volume 51 of The Absolute Sound magazine in 1988. Colloms undertook a complete dissection of the design of the Goldmund Reference including the single point grounding methodology that Goldmund employed. I would highly recommend anyone interested in TT design obtain a copy for reference. Some of these mechanical grounding principles were deployed to their entry level products such as the Goldmund Studio that richardkrebs owned.
Each time there is a change in materials some energy passes through and some gets reflected back. For example if you have a mat on a platter, then some energy will pass through from the mat to the platter, but some energy will reflect back to the record/stylus and smear the sound. This is basic materials engineering.
Providing properly designed pathways to drain unwanted energy from the stylus, record interface through the platter to ground in order to prevent coloration from energy reflecting back into the record and stylus has been around since the 60's, moreso in Japanese audio circles.
The Final Audio Parthenon from Japan released in 1971 is essentially a nude turntable with defined energy paths from stylus to ground. The designer Kitamura explains that the amount of energy generated by the interaction of stylus and groove is much higher than required to drive the coils, and therefore unless the balance of energy is drained to ground, it rebounds and resonates the turntable, arm and cartridge, superimposing resonances back into the playback. This is documented in a review of the Final Audio TT in TAS Volume 8 #30 in 1983. The absence of resonance, which results in a clarity and density of tone unparalleled by other TT's I have auditioned such as the Goldmund, Micro Seiki's. SP10's, L07D's etc is one of the primary reasons I purchased the Final Audio Parthenon.

08-29-13: Ct0517
If I understand you are using three leg supports under your triangle TT.
One is the "alpha" leg the leader for energy transmission, while the other two are slower followers? Are you not worried about energy in the plinth getting built up in those two areas with the pvc legs? Did you have a way to test this other than by listening?

08-29-13: Richardkrebs
Like your Alpha leg analogy. Actually, with the other two feet, we are trying to block energy transmission as much as possible although in practice I doubt that this can truly be done.

Actually it does work.
With electrical grounding the signal always finds the path of least resistance.
With a mechanical ground, as discussed, providing a single path to ground results in a cleaner dissipation of energy. Mechanical resonances and disturbances will find the path of least resistance to some degree, but there must be a logical path in terms of materials selection, transmissibility etc from platter to ground to minimise backward reflections. In the richardkrebs example the resonant behaviour of the hard footer will result in a specific resonance absorption and transmission/reflection profile, whereas the soft feet will attract a resonance absorption and transmission/reflection profile that is quite different. If one were able to put together a mathematical model of the structure and materials composition, then minimising the resonant behaviour and backward reflections can be calculated quite easily and would be more reliable than listening since no system exists without colourations due to room or other equipment..

Yes the concept works. I used it in my first Home built TT, back in the late 70's. The idea was borrowed from an ancient Gyro testing table I saw at Air NZ. It had adjustable feet with wooden pads connecting the floor and one fixed cast iron foot. Cast in one piece into the chassis.
I asked my supervisor why?
His answer "to keep it still"
The table must have been 20 years old back then. Meaning the concept is at least 50 years old.

My comment about not truly working was around the " road block" probably not being absolute. There is likely some leakage thru the softer feet.

Cheers.

The table must have been 20 years old back then. Meaning the concept is at least 50 years old.

Ah yes - the tripod. A tripod provides stability against downward forces and horizontal forces and movements about horizontal axes. The positioning of the three feet away from the vertical centre allows the tripod better leverage for resisting lateral forces.
Been around since the Mycenae age - the 16th to 12th centuries BC. Had I been around at that time I would have used it in my first TT.

Dover - Been around since the Mycenae age - the 16th to 12th centuries BC. Had I been around at that time I would have used it in my first TT.

I believe that Mr JC Verdier took the concept of the Platine Vintage Granito from this period. He just improved on the remote motor a bit. It used to be a human pedaling back then trying to keep speed stability.

“Granito is a material composed by little pieces of marble of very different origin agglomerated inside a mold with cement. Machined and polished. The resonance of the plinth with its suspension is about 5Hz and it is well absorbed by the air cavities."
Mr. JC Verdier

So there are different ways to go about this.
You can try to pass resonances through and hope it is one way. Or you can absorb them. The Platine has been scientifically analyzed, studied, and has passed the hardest test of all - time.

The way this Platine is made, I feel you could probably place it on any decent kitchen table and get good sound. My Verdier manual provides three options for installation. hard wearing furniture, wall mount, sandbox.
My Vintage Granito is on a solid maple platform which utilizes an elongated sandbox, on the concrete floor.

Not as pretty and "audiophile" as a vibraplane. But I don't have to worry about maintenance and adjustments due it going out of level and leaky bladders :^). I also don't feel a need to please other audiophiles....just myself. But I am my worst enemy. Glad I am a hobbyist and not in this business. Now with my other hobbies I can see getting into one of them on a business level later.
cheers

Richard – thanks for turning me onto the “alpha leg” :^)

I may try it with the sp10 setup later. One Stainless Steel leg and 3 PVC or other slower material legs. The JN Lenco uses 3 bear paws. I can’t even begin to imagine how many development hours Jean Nantais has into this table. It is very much about absorption of resonances and works well. So I am reluctant to try it here. Its 100 pounds doesn’t help. If JN is perusing here and sees this maybe he can attempt it. Something tells me he won't looking at a thread with a title that used the word Nude for any ideas :^)
Maybe I will email him.

Cheers

09-02-13: Ct0517
Richard – thanks for turning me onto the “alpha leg” :^)
I may try it with the sp10 setup later. One Stainless Steel leg and 3 PVC or other slower material legs.

With regard to your proposed 4 legged experiment, it appears that the physics and engineering principles underpinning the optimal mechanical grounding principles have been overlooked.
A tripod is inherently more stable than 4 legs. A tripod distributes the weight evenly around the centre of gravity across its 3 legs. This is why cameras and theodolites are usually mounted on tripods, they are more stable. Note also your Verdier TT uses 3 feet to take advantage of this principle.
The use of a grounding leg plus 2 non grounding legs to achieve a single point mechanical grounding works far more effectively with a tripod ( 3 legged ) configuration. The Goldmund Reference Technical Report in the Absolute Sound magazine, issue 51 has an informative discussion for those wishing to understand the principles of mechanical grounding.

Thanks Dover. Sometimes I get ahead of myself when I get hold of an new idea. I tend to get a little giddy and feeling like a little kid. My version 5 will support 3 legs not a problem as they are screwed in on both sides. Project added to the overall list. Its no. 14 right behind no. 13 – Build wife new kitchen :^( I am thinking of outsourcing this project so I can play with my audio stuff more this winter.

A tripod is inherently more stable than 4 legs.

Not true........try sitting on a 3 legged stool?
Four legs is generally accepted for stability in chairs.......but in office chairs on castors.......even 4 castors is not sufficient for stability with 5 castors being mandated for safety in the workplace.

The reason 3 supports is often used for turntables......is that the 3 supports will ALWAYS make contact on the supporting structure.
With 4 supports......depending on the load of the turntable.....only 3 may be making full contact.
With 4 legged chairs......a person's weight will 'spread' the bottom of the legs so that all 4 legs are weight-bearing whilst without the load of an occupant......only 3 legs may be fully in contact with the ground?

Hi Dover,

"A tripod is inherently more stable than 4 legs." I've read variations on your statement many times. But I wonder under which conditions it is true?

Is a tricycle more stable than a (4 wheel) wagon? Think about which one would be easier to tip over if making a sharp turn. But if that is an unfair example for a stationary object, then which one would be easier to tip with a shift in loaded mass while otherwise stationary.

As for camera tri-pods, I believe there are two reasons for their design. First, they are lighter and more portable than quad-pods, all else being equal.

But it is their second design feature that really gives the advantage. The three legs are splayed well outside the center point of the mass they support by angles. And I think it is the angles of the legs which provide the stability, rather than the number three.

Said another way (sorry, I'm trying to find the best way to express my sense of this issue and my question), if we have two small tables of the same weight and height, one has three vertical legs, the other four vertical legs, which will be more stable? If you push on the edge of the top surface, midway between any two legs of both tables, which one is more likely to tip?

Thanks Halcro, you beat me to it. .^)

Hi.

The Gyro testing table had 6 cast iron legs. Five of them were height adjustable with wooden decoupling pads. The sixth leg had no adjustment and it directly coupled with the concrete floor.

Halcro/Pryso
We are in agreement on the "stability" of 3 feet.
My comments on stability are in the context of draining unwanted energy using single point mechanical grounding. I also assume the tripod is correctly designed for weight distribution to give stability and deal with rotational energy around the central axis. I also assume we are not driving the TT down to the grocery store and we are not in the habit of sitting on it.
Very few surfaces that the gear is mounted on are truly level, and in that context 3 feet will naturally load predictably, whereas with 4 or more feet they will have to be adjusted precisely to provide predictable loads through each foot. This is almost impossible unless you have pressure pads under each foot. The Mana stand manufacturers' recommended set up procedure for their 4 legged stands were to adjust the 4 feet with a stethoscope and tapping technique. Imagine doing this on each shelf as well as the feet ! And if you have a wooden floor that moves, you'll need to retune them each season.
In my 30+ years of audio I have applied the Goldmund mechanical grounding principles on all my components ( and many others ) and in all circumstances converting equipment ( TT's, amps, speakers ), speaker stands etc to 3 feet, single point mechanical grounding has yielded significant improvements in clarity, focus and the removal of resonances and tonal distortions.
In the Goldmund amplifiers, the mains transformers are grounded directly by bolting the transformers to the Goldmund footer, and the transformer is attached to the chassis by lossy connectors. The electronic circuitry is directly coupled to another of the 3 feet for optimum grounding and that foot has a lossy connection to the chassis. The net outcome is that each of these sources of resonance are single point mechanically grounded, and separate from each other, even though they exist in the same chassis. The chassis is decoupled from the others and grounded through the third leg. With non Goldmund amps the "alpha" leg is best placed under the mains transformer which is usually the largest source of resonance.

The Gyro testing table had 6 cast iron legs. Five of them were height adjustable with wooden decoupling pads. The sixth leg had no adjustment and it directly coupled with the concrete floor.

Interesting

gave this more thought. My current version Sp10/Armpod testing TT is different from the Gyro as it is a rigid structure bolted into the base/plinth. No provisions for height or level adjustments. All height and leveling adjustments are done by the three adjustable AT-616 pneumatic footers under the base/plinth. In this case the actual TT system feet are these footers and I use three.

As noted earlier the ET2 tonearm has its own leveling system independent of these feet for final leveling. I level the platter as best as possible then the tonearm. My SS legs are acting as supports and are not the actual TT system feet. I would want to keep all four for stability and rigidity. Sounds to me like trying this out means changing out one of the AT-616's for an alpha leg ? The one under the tonearm in the pic ?

I haven't been on this site for a while and just caught up with Halcro's brave changes. I admire your "out of the box" thinking, Halcro. I could never feel comfortable looking at the electronic guts hanging out of my TT.

My TT-101 is now seated on a "SolidSteel WS-5" brand wall shelf - which is bolted to a brick wall. This wall shelf is a heavy steel perimeter frame supporting an mdf shelf which is leveled by 4 spikes into the steel frame.

This excellent support - perfectly leveled (plus I did another adjustment to the height of the bearing thrust plate) has solved all of the start-up problems it was having. It starts immediately and runs at exact speed without hesitation at the push of a button - just as it should.

The turntable sits on that mdf shelf using it's original steel can resting on 3 perimeter brass heavy points and a 4th heavy point sitting dead center under the can. That 4th point is a drain for the can and is important even though the can is damped.

I have discussed at length how the can is a major problem and needs extensive damping. Mine is lined with bitumen damping sheets (about 1/4 - 1/3 of the venting holes remain open) and has a heavy rubber strap around the top where it mounts to the structure of the TT. Even though only a fraction of the ventilation holes remain in use there is no heat build up - the can stays cool to the touch after spinning for hours.

I believe that I have reached a stable point and will leave well enough alone. Ella Fitzgerald is scatting in agreement.

Aigenga wrote---"This excellent support - perfectly leveled (plus I did another adjustment to the height of the bearing thrust plate) has solved all of the start-up problems it was having. It starts immediately and runs at exact speed without hesitation at the push of a button - just as it should".

Is it possible to explain further how this is accomplished and also post some pictures to help a layman like me to fully understand what you have done.

Which part interests you - the leveling or the thrust plate adjustment?

Thanks Aigenga..........I knew the looks would not be to everyone's taste....and initially scared me somewhat :-0
But now I think the covered 'guts' look stodgy in comparison.
As Ecir said above.......I think it looks "wicked" :-)

I really admire the way you have supported your TT-101 on the wall-hung shelf....and its interesting to read about your use of the central 4th spike?
I remembered well your 'damping' of the outer metal casing and following your advice, I bought 2 bungy straps on Ebay and wrapped them around the outer casing....without however hearing any differences?
It was your reported improvements in damping the outer casing which encouraged me to remove it completely :-)
And the improvements have indeed been audible....but how much is due to the removal of the casing or the better supporting steel cradle or the decoupling of the deck from the cradle support....I don't really know?

The thrust plate.

Halcro, I am happy for any (if any) role I played in inspiring your creativity. In our crazy hobby, everything matters and often it is impossible to figure out what does what to our precious sound.

Audpulse, Sorry but no pics available on this one. Here is my best info:
1. first why do you want to adjust the thrust plate - is there a problem with how the platter turns? If not then sit back and think about it some more.

2. if you want to go forward keep this in mind: the pressure on the plate is not random, not at all - if you get it wrong the platter either won't turn or it might make it harder for the table to get a grip and get spinning. Which I think might have happened to me.

3. The TT101 has a center screw that is easily visible and accessible from underneath once you remove the bottom can. To do this it is critical that you first remove the platter, then turn the tt upside down onto a bowl that is broad enough to sit stably as you work.

4. The center screw provides the pressure on the thrust plate. It is screwed in to an exact spot - don't forget that. It is also sealed with Loctite or some such sealer which you will need to scrape away and replace when you replace the screw.

5. Once you take out the screw you should replace the oil in the well - about 1/2 ounce will do. I suggest synthetic motor oil. You can wipe it out with a clean cloth. Careful in that there is a loose ball bearing sitting there and you don't want to lose that.

6. Reassembly is just that, but don't forget to seal that screw or your oil will leak out.

I hope that is useful to you. Questions?

I was thinking last night……because Aigenga’s TT-101 is nude and mounted on a wall-hung shelf like mine……I know exactly what it sounds like?
Same with Banquo’s ‘nuded’ Victor.
But I also know what most Raven AC turntables sound like (assuming they are not plagued by uncontrolled Structure-Borne feedback) and Rega Planar 3 turntables and Linns and Caliburns.
And if I was familiar with the big Micro Seiki 5000 and 8000 models…..I would probably know their ‘sound’ as well?

But I have no clue how a ‘re-plinthed’ SP-10 Mk2 or Mk3 sounds or how a re-plinthed Lenco, Garrard, Thorens et al would sound and I can’t imagine how anyone else can?
If every plinth can sound differently depending on material, sizing, construction, damping, resonance-draining and footers….how does any example sound like another?
And if they all sound slightly differently…..who decides which is more accurate and how is this decided?

From a purely objective and somewhat logical viewpoint…..if a ‘self-contained’ turntable like a direct-drive model (and to some extent Idlers) can perform their function without being encapsulated by a plinth…..why is it not reasonable to conclude that any changes to the sound resulting from the addition of a plinth is a ‘colouration’…an ‘addition’ or a ‘deduction’ or a ‘corruption’?

How do the ‘plinth’ advocates reconcile the fact that no two examples can possibly sound exactly the same?

Halcro.
You are using a plinth.
It is the shelf upon which your TT sits via the spikes you are using.
It would also seem logical that different shelf materials, size, shape, support method, spikes, et el would make a difference.

Richardkrebs,
I imagine it’s possible to ‘define’ an object into existence to suit one’s argument….but I’m not sure where it gets you?
To define a ‘plinth’ as a ‘shelf’ allows for a ‘rack’, a ‘platform’ and of course the ‘floor’ to also comply with that definition.
It gives us the situation where audio items like power conditioners and DACs and SUTs and preamps and amps are all on ‘plinths’?
And for those with a REAL turntable ‘plinth’ on a Minus K stand on a shelf on a rack on a floor……..we have a plinth on a plinth on a plinth on a plinth……..?

It would also seem logical that different shelf materials, size, shape, support method, spikes, et el would make a difference.

This would only be “logical” if one could conclusively prove that there was ‘stored energy’ within the shelf or within the object ON the shelf which REACTED to the “materials, size, shape, support method, spikes, et al” in a way that affected the motor, bearing, platter, record, stylus, cartridge and arm in a turntable system for example?
Despite the availability of accelerometers and other devices designed to measure and quantify vibrational energy and its transfer within materials…..I have seen no scientific evidence to support the many statements made by audiophiles on the nature of ‘vibration draining’ in regards to turntables….and any quantification of such?

The vast majority of audio systems are supported on the floor of the listening room albeit on racks or stands of some sort.
The vast majority of those floors are suspended timber frame or suspended concrete slab…..very few are concrete slab-on-ground.
All suspended floors (be they timber, steel or concrete) are under bending stresses of various magnitudes which create low frequency acoustic energy within the structure.
This low frequency energy (often resulting in movement) is transferred to the rack/stand/shelf supporting the equipment and results in higher frequency energy transmission and movement which is passed through to the equipment supported thereon.
With all this low frequency energy swamping the stands, racks and shelves……it is no wonder that differing methods of support and differing materials all have an effect on the transmission and damping characteristics?
But you are mistaken to assume that those who have absolutely no structure-borne feedback will also experience the same phenomena.
My floor is a reinforced concrete slab-on-ground topped with polished granite and is totally bereft of any structure-borne sound.
My turntables sit on a stressed-skin MDF shelf cantilevered from a masonry structural wall supported on that reinforced concrete slab.
The turntables sound identical whether they are sitting directly on the polished granite floor or up on the cantilevered shelf.
I have tested many methods of support for the turntables including an additional independent shelf on top of the cantilevered one….sorbothane feet, Delcrin footers, Stillpoint Ceramic feet, Stillpoint Ultra Minis, ceramic cones, aluminium cones, steel cones, plastic cones, brass spikes, steel spikes and stainless steel spikes. I have placed various materials between cones/spikes and the supporting shelf including metal coins, plastic, cardboard etc……and with all and every variation…..there has been zero change to the sound.
When there are no Structure-Borne feedback problems……there is nothing to affect the turntable adversely (other than Air-Borne feedback…..but that is another can of worms).
In fact a sure way to determine whether your room suffers from Structure-Borne Feedback is to see if changing the spikes, rack, footers etc results in an audible change?

But back to the plinth……I’m sure you have much to contribute to a discussion on a ‘real’ plinth into which a turntable like a DD or Idler may be mounted? :-)

Halcro.

We are both blessed with having music rooms that have concrete floors sitting on mother earth.

My definition of a plinth is likely a little wider than yours. To me it is.. "the structure that maintains accurate dimensional stability between the record surface and the tonearm". I am sure that you will agree that dimensional stability in this area is critical. I have also called this structure a "loop" in an earlier post.

By that definition your very nicely built stainless steel motor support, the shelf(or floor) and the equally nice arm pod are all parts of the plinth.

It would be reasonable to expect a change in the sound, if you were to change the stainless steel support for say a large diameter cardboard tube. Likewise we could expect a change in sound if the arm pod was made from say balsa wood. I suspect that your choice of these materials was based on experience and sound logic.
Since substitution of different materials would likely alter the performance, it can be inferred that your "plinth" does have a sound.

Aigenga,
In the TT101 Service Manual it explicitly states that the bearing needs no service, which would include periodic lubrication. Bill Thalmann also strongly advised against trying to "lubricate" it. You may fairly respond, and I would agree, that Victor probably did not envision a 30-year lifespan for the product. Therefore, at this point in history, some attention to the bearing may be merited. What did you see when you first accessed the bearing? What was the condition of the lubricant, the bearing, the thrust plate? I am just curious; I don't think what you did was necessarily "wrong" in any way. What lubricant did you use when you serviced your bearing? Thanks.

Halcro,
I think what you have now is a "plinth" by my own definition. Many if not most of the best belt-drive turntables are built with solid, heavy bases that do not afford an open deck surrounding the plane subjacent to the platter; I always thought that was a good idea, as is yours. If I had it to do over, I might have fashioned my own slate and wood plinths in a more minimalist way, but I am not about to do it over. By the way, my Lenco most of all benefits from its dense slate plinth. Why re-open the argument?

Lewm, the fluid was brown and had particulates in it. The bearing looked fine, the plate is soft white plastic so was dented by the bearing but otherwise fine. I do not recommend opening the bearing up unless you have detected a problem. I thought I had made that point in my narrative. But it isn't a real issue if you do it right, and it also enabled me to put rubber/steel grommets between the motor and the frame. All for education and hobby-fun.
Gary

I am all for "education and hobby fun", dagnabbit!

The Denon DP80 bearing is also supposed to be "forever", so I've done nothing to the bearing in my DP80, as well. The fact that your bearing fluid was brown indicates it probably was a good idea to change it. However, I personally would be leery of over- or under-tightening that slot-head screw that forms the seal at the bottom of the bearing well (in the TT101). Anyway, you got away with it. The thrust plate might be teflon, probably not "soft plastic".

Did you mean to imply that you needed to access the innards of the bearing in order to install rubber/steel grommets between the motor and the frame? I am not sure why, if so.

I cleaned out my bearing as well. For no particular reason other than that Gary made it sound easy--and it was, sort of. My oil was also brown and unsightly. I used Mobil 1 20w-50 motorcycle oil as replacement. One thing to note for those considering doing this is that the screw used to access the bearing is also used to raise and lower the platter. As I found out, the platter needs to be at a particular level to avoid scraping and/or locking. It's not trivial to find the correct level and it's a serious pain to handle the unit and flipping it right side up to check whether one has found the sweet spot.

So: I pantsed a la Halcro my Victor a couple of week's back. Before I did so, I listened intently to 3 album sides and then subsequently compared the differences. I changed nothing else. Like Ecir38, I had suspected that the differences Halcro found were due to his new supporting system and not so much to the absence of the metal cover.

I'm here to report that my suspicions, at least as they pertain to my Victor, are wholly unfounded. With respect to all 3 album sides I used the changes were the same: the character of the instruments including voice became more nuanced (microdynamics?) and impactful (in terms of scale but not loudness, if that makes sense) than they were. I can better hear the music as a whole. For example, the first movement of Mahler's 9th can sound like a convoluted mess if the musical 'line' is lost. After the pantsing, I could better follow along because certain passages that were relatively obscure suddenly came to life and became 'ready to hand'. Unfortunately for me, my system still cannot reproduce the double bassess accurately--but that's another issue. Ry Cooder's guitar work in 'Into the Purple Valley' has never been as nuanced and transparent. And Paul Desmond's sax in Brubeck's 'Gone with the Wind' has never sounded so right. I am pointing out only the most dramatic cases; there are many more subtle ones.

One other difference to note is that everything seems quieter. I don't mean the noise floor has dropped, but rather that I seem to want to turn the volume up nowadays. I think the desire is connected to the decrease in distortions (trademark, Raul) that I was subjected to prior.

One potential caveat: I recently changed my headshell leads to Oyaide silver. I had them in during the initial unpantsed audition, but they might not have been fully burned in (if you believe in that sort of thing). I personally don't believe the differences I heard can be accounted for by the leads.

fyi: the copper looking thing underneath the victor is a Texas Instruments Shield. I had planned to use it underneath my platter mat but it refused to lay flat--that and I don't currently use anything but a piece of pigskin. Yet another benefit of listening to Halcro.

I agree with all that the metal chassis is a sonic problem and removing it entirely might be a good idea. I am going to try it. I had already come to the conclusion that the "pants" on the DP80 ought also to be removed, but first I am going to try damping the DP80 chassis with two thick strong rubber bands that were gifted to me.

The TI Shield won't do anything down there, especially since it is apparently not grounded. To ground it, just solder a bare wire to it anywhere on its surface and run that wire to tt ground. But in that position, it can't be of much help regardless.

The only downside to de-pants-ing is that it removes the RFI shielding afforded by the ferrous pants. Thus I would be cautious not to interpret changes you may hear in the sound solely to removal of resonances. There could be some RFI contamination via the cartridge. Sometimes any change to the sound that is new is also thought to be good, until you listen for a long while and realize you are fatigued by something irritating in the new sound. I hope this is not an issue, however.

fwiw, I tested the cover grounded vs ungrounded and never heard a difference. I just put the ti shield there on a whim, because I had it and said what the hell. I also have cut pieces of it between the motor cover and the platter. Again: what the hell.

Your word of caution, Lewm, is duly noted. I'm about 2 weeks in and I've not noticed any adverse effects. Fingers crossed. But the differences I'm hearing don't seem to be the type that would result in future unhappiness. For example, it's not as if I'm getting 'fuller bass' or 'extended highs' or a 'sweeter midrange', all of which can potentially lead to dissatisfaction in the long run.

I forgot to mention that pantsing has not changed the start up speed (as Halcro noted on his): mine still very occasionally starts at 33.32. As I noted before, I think it's due, in my case, to using a duster that puts pressure on the record as it gets up to speed. I've not ever noticed it start at 33.32 when I do not dust.

08-27-12: Dover
Victor 101 -
Could you get rid of the flimsy bottom cover completely and mount the nude deck via an inverted tripod ? It doesn't look particularly rigid from the photos.
Potentially could you remove the internal transformer and some of the electronic boards from the main chassis and mount them separately to eliminate as much vibration as possible. Make sure all internal joints are as rigid as possible.

It is pleasing to see my suggestion in August last year to remove the flimsy bottom cover being successfully trialled at last. Thanks to all who have tried it.

09-10-13: Halcro
Despite the availability of accelerometers and other devices designed to measure and quantify vibrational energy and its transfer within materials…..I have seen no scientific evidence to support the many statements made by audiophiles on the nature of ‘vibration draining’ in regards to turntables….and any quantification of such?

You appear to be saying that the "improvements" you claim your new TT support structure are merely a figment of your imagination since you state "I have seen no scientific evidence to support the many statements made by audiophiles on the nature of ‘vibration draining’ in regards to turntables"

My view is that there are several sources of unwamted noise and vibration in TT's. That is one of the reasons that TT manufacturers publish noise floor specifications in the form of xxdB.
When playing a vinyl record, the stylus generates noise and vibration as well as the music you hear, resulting in vinyl record wear and stylus wear.
Most turntables have a platter that uses a spindle and thrust bearing to provide the ability to rotate. When the platter bearing rotates, this generates noise. Worn bearings are a direct consequence of this friction.
Both of these phenomena are a source of vibration and noise.
In order to "see" it, I would suggest you purchase a stethoscope and have a listen to your turntable, whilst it is working. Then have another listen when it is not working. This simple experiment may be revelatory for you.

Lewm, I think the belts are a good idea but insufficient. You need the suspenders as well on those pants. By that I mean the sound dampening sheets.

On my iPhone I have an app called a Tesla meter which measures stray electrical currents (RFI). I got this to measure what was coming through my TT's can. The results told me that the transformer puts out a notable amount. I don't recall what the situation was with the ground wire at the time as I have used it in multiple configs. As I recall, the tranny faced the tonearm - food for thought. Clearly I should do some clean experiments and have good data to report - in a day or two I should be able to get to it.

Banquo, I feel guilty enticing you down the path of changing the oil and subsequently getting bearing-level problems. I experienced the same and that is why I emphasized returning the screw to the exact position in my last write-up. But of course that was too late a warning. Sorry.
Gary

I am delighted to hear Banquo confirm my listening impressions.
I am well aware of the audiophile’s ‘need’ to hear improvements with any change. Especially a change invested with a personal ‘attachment’? :-)

One other difference to note is that everything seems quieter. I don't mean the noise floor has dropped, but rather that I seem to want to turn the volume up nowadays.

This is what I meant by the term “purer”……and “turn the volume up” is exactly what I do also……
Incidentally….I spoke too early about the ‘fix’ to the speed read-out.
Yesterday it went to 33.32 rpm on ‘start-up’ before hitting 33.33 rpm…

I’m intrigued Banquo about your bass problems?
Are these a function of your speakers, room or amplification?
Surely not a source issue?

Dover,
I have a stethoscope and have done all the listening you suggest...and more, and hear nothing "revelatory" in regard to 'noise' within my turntable structures.
However this is by no means a scientific or 'white paper approved' form of documentary evidence which laboratory testing could easily provide?
Your use of terms like "noise", "friction" and "vibration" are inexact, undocumented and unquantified.
Hardly a convincing argument regardless of how often you continue to repeat it?

Lewm,

Why re-open the argument?

Errr.....because that is the subject of this Thread? :-)

Incidentally......have you managed to listen to your TT-101 yet?

Now here's a Belt-Drive from the famous Melco brand.
The legendary Melco was a High-End Japanese turntable manufacturer equal to Micro Seiki with cost-no-object products in the 1970s.
This model I particularly like because of the strong skeletal steel backbone 'plinth' which should satisfy Lewm and Dover completely :-)

Your TT may have to be confiscated siting indecent enclosure :)

And here is the equally famous Takai Lab Final VTT-1 belt-drive turntable similar to Dover's.....although he has the Parthenon model I seem to recall which is quite different to this one?
I particularly love the 'Copernican' ideal of the separation of platter and arm-pods.....and this execution appears to be particularly elegant.
Again Dover and Lewm should be well pleased with the 'plinth' arrangement selected here? :-)

Your TT may have to be confiscated siting indecent enclosure

Heh heh....
OK you twisted my arm....
An even more indecent shot......and another

Perhaps a thong. But then one's other turntables would be attracted.

I hope Halcro does not mind this diverting of his thread topic from nude to TT101 nude, but I have a TT101 question for other users: Even after Bill Thalmann blessed mine, I still have the following occasional problem. The TT will start up and go to 33.32. Then after 5-10 seconds, it goes to 33.33. After about a minute or two more, it will go to 33.34. Very shortly thereafter it will shut itself down. The tachometer reading disappears, and the brake effect does not occur. The platter spins freely until it loses momentum. If I manually press the STOP button BEFORE the unpremeditated shutdown, there IS a correct brake effect. I had been thinking that there is a problem with the reverse servo mechanism to explain this, but you guys have me thinking that there may be some inordinate drag on the platter, meaning my bearing may need service. On the other hand, if that were so, I would expect to hear a frictional sound (the table is dead silent) and I would not expect the platter to spin so freely and silently after shutdown. Comments?

I am embarrassed to tell Bill about this glitch, because it worked perfectly in his shop when I picked it up. But of course I will tell him eventually. He is a kind and patient man, moreso than I.

Lewm: My table basically went through all the symptoms you describe and then some. My tech reasoned through and tried testing many of the complex explanations. But in the end, we discovered that it was all attributable to bad solder joints on the 'feed thru eyelets'. He resoldered ALL of them. He said he knew of companies that used such type of boards and that they had reliability problems. Since you're handy with a solder gun, I'd try this brute method first before potentially wasting time investigating the subtler possibilities.

Aigenga: No worries. The thing is, I did note the number of turns and even marked the spot but when I put it back together the platter was completely locked up. Obviously, I screwed up somewhere--but I believe I know how to count, so it's still unclear to me what happened. I have zero plans on doing that again for the next 30 years.

Halcro: I don't have a general problem reproducing bass, but the double basses on that Mahler record, while better after the pantsing, sound far from adequate. I blame my speakers or the lack of subwoofers. Or, for all I know, it's the record itself. I just purchased another better copy of that record so I can test the last possibility soon.

fwiw, I don't have anything invested in the new set up except 15 minutes of time (2 to take the cover off and the rest to realign the tonearm and cartridge). The improvement is remarkable. It's along the same trajectory as the improvements I noted when I moved from my sp10 to the victor.

OK, now I am confused and a bit concerned. I used the Tesla meter to measure stray magnetic fields (as the device tells me) and lo and behold the only area that had high readings was at the top of the platter mostly on the right side of the table. Right where the cartridge tracks the record!

I repeated the measurements with the table grounded and not grounded, with my lead mat on and off, with the platter spinning and stopped, with the power on and off.

I even tried it on a TT-81 that hasn't spun in a year and got similar results! Is this a problem for DD turntables?

There is something in the TT itself that emits a notable magnetic field - I would guess it is the motor. I don't know how to address this but I certainly think that the magnetic operation of the cartridge is affected by this and not in a good way.

I would really like to hear that someone else has repeated this experiment and what they found.

Time to investigate Mu metal and how I can fashion a shield.

Gary

Banquo, Your idea of the cause of the glitches in my TT101 operation is a good one. When we first got it to run at all, it exhibited all sorts of crazy forms of malfunction, even though every single electrolytic capacitor had been replaced, and Bill eventually tracked it down to bad solder joints or solder tracings, just as you say. He told me he spent a lot of time re-soldering various tracings (for which he did not charge), and his work resulted in what appeared to be complete success, based on how the table worked in his shop. It is quite possible that the mechanical trauma associated with travel from his place to mine (about 20 miles on the DC Beltway, which is not exactly cushion-y) put some stresses on other tracings that are now faulty. Can you be more explicit about what you mean when you say "feed through" tracings? I was thinking that soldering of the wires in one or more of the many multi-prong plugs that interconnect the various PCBs could be the source of the current problem.

Halcro, Of course you have every right to post on the subject of this thread (heh-heh). I personally have no desire to argue further about plinth, no-plinth, or arm pods. This is not because I don't care but rather because I can see now that your rig is very nicely done so as to mitigate any criticism I might have of the concepts. I still think that the basic structure of the L07D, with the rock solid connection between the bearing housing and the tonearm mount, is ideal, whether or not the L07D is top dog in all other ways. And as I've said several times, I do also think that getting rid of the "deck" structure surrounding the platter is beneficial. The more the tt chassis resembles a cylinder with the diameter only slightly greater than that of the platter, the better. This is one way toward good sound, not the only way. Fortunately for us, it is easy to achieve the latter goal with the Victor and Denon DD turntables.

Lew, I think what Banquo is talking about is that wires that go from one board to the other are fastened by wire that is just wrapped around a stud that is soldered to pcb. This is a known problem and should be addressed if it hasn't been already.

See pic here for description notably at tranny's a/c connections. If you look closely the same procedure is used throughout. Now these pics are from a TT71 and not sure if the 81 and 101 are similiar.

http://amp8.web.fc2.com/amp-etc/record/victor/tt-71-2.htm

http://www.amp8.com/amp-etc/record/victor/tt-71.htm

Ecir and Banquo, Before reading Ecir's post, I was about to say that I looked up the definition of "feed through eyelet" via Google, and to my amazement I found the definition. I had never heard that term before. Ecir, in one of those URLs I do see a number of short posts with wires wound or obviously soldered to them, on the various PCBs. There sure are several of those in the TT101. I will check them. But the formal definition of a "feed through eyelet" is a connector that goes through a PCB, connecting a circuit on one side to a circuit on the back side of the same PCB. Guess I will look for those too. (Or perhaps those posts do connect to tracings on the other side of those PCBs, which would not be visible in the photos.) Thanks to you both.

Yes those post are soldered on the other side and are used in that fashions so as not to have to remove the pcb to service other conecting components.

To me this is a prime example of a reason to service the bearing of the motor, nothing last forever as much as the manufacture would have you believe.

There were no bad parts, just bad connections. I ended up resoldering all the feed thru eyelets, then flipping the board and removing the solder with a sucker, then resoldering them with much less solder. They all look pretty clean now. I know other companies that used the eyelet method had reliability problems. For some reason the solder cracks around the eyelets, probably related to different coefficients of thermal expansion.

That's from an email my tech Dave Brown sent me. In a different email, he distinguishes between what he calls 'feed thru eyelet' boards and 'plated thru' ones. The Victor evidently uses the former. I am completely ignorant of the meanings of the 2 terms--am just passing on others' wisdom as I received it.

The problem I see with the post connection is if anyone has fooled with them in the past the leverage from the post will have a tendency to move the eyelet on the other side if done without caution. I would unwrap then rewrap with less turns and resolder eyelet on backside and solder the wire.

If you translate that link you would see the ones with solder are suppose to be the repair.

Very informative. Thanks again.