Vintage DD turntables. Are we living dangerously?

I think Halcro once posted photos of the circuit boards in his Halcro preamplifier.  Either he or someone else did. The parts and the entire upper surface of the PCB were shown to be coated with some plasticene material, in sort of an off brown/gray color.  Impossible to service, but also impossible to copy, and said to have been applied for its dampening effect.

Perhaps you are  like me; as I have aged, I am less and less inclined to DIY or Do-It-MYself, except when it comes to the actual electronics.  I still enjoy messing about in a tube circuit. I look at the 3 slate plinths I had made for Lenco, Denon DP80, and SP10 Mk3 (slate + wood in this latter case), and I wonder where I got the patience and energy.  I would not take on such projects again.

Richard, What interests me most is WHY did you decide to make an entirely new platter for the Mk3?  And what are the consequences to how it works associated with incorporating one half of a speed sensor device into the platter?  (What's a "toothed magnet"?  I've never been bitten by a magnet.) Did this entail a basic change in the circuitry?

I guess I am guilty of being a frequent advocate of replacing electrolytics in vintage DD turntables, meaning electrolytics that are typically at least 30 years old. My main reasons for that are (1) it's cheap insurance against a future failure, and (2) in the worst case scenario a bad electrolytic that might cost one dollar to replace (if you can solder) eventually can result in the destruction of an irreplaceable transistor or IC.  I agree that when you do replace ALL the electrolytics with new, you are probably discarding a few capacitors that are still good, but the cost is trivial.  (I'd love to see an 80-year-old electrolytic that still works fine, however. We're talking 1936.)

Plus there is the added possible benefit that modern electroytics are generally a little better, specification-wise, than they were in 1980. Your "stuff" might work better because of that.

After two weeks or so with my functioning TT101, I would say that the TT101 is right up there with the best of them, and I do own two of the best of them (SP10 Mk3 and Kenwood L07D) for comparison.  Arguably, the Denon DP80 would be a third, but I don't use it.  By scuttlebutt only, I think of the GT2000 as second tier, but that's a completely unfair assessment based on gossip.  I wouldn't put much stock in TVK, either. The write-ups in TVK are probably not done by someone who listens to the turntables.  (GT2000 is the turntable; 2000GT is the collectible car made by Toyota, I think. But it could be the other way around.) Does the GT2000 have a coreless motor?  What sort of servo does it use? How is the platter made and what does it weigh?  (It does appear to have an over-size platter with mass disposed to the edge, a nice design.) These are things I would consider in deciding between the TT101 and the GT2000, absent the chance to compare them in a single audio system.  (Coreless motor is to be preferred, in my opinion.)  The one I've got to try is the Pioneer Exclusive P3, but every time I have the chance to buy one, I cannot justify the purchase what with the excess of turntables already in my stable.  Then there's the Luxman, which Dave G owns.

Totem, I will let JP comment if he sees fit, but "Bi-directional servo" was apparently mostly a marketing gimmick, used by both Victor and Yamaha. The servo on the TT101 was well designed, according to JP, but really not different from or any more "bi-directional" than that used in the SP10 Mk3, for one example.  

I think I remember now why I was a bit down on the GT2000; I once saw some photos showing stress fractures in the tonearm, around the pivot point, arising from the fact that some key parts of it are actually made of plastic. But if it has a coreless motor....  Also, it appears to have a high mass platter.  There's a version called the GT2000X, which sports a large apparently metal brace around the plinth. I think it was an accessory which could be purchased as an option.  Anyone here know about that?  The GT2000X looked hot and cool! (Both good things.)

The Sony PSX9 seems to have a built-in phono stage.  Is that correct?  I wondered how it would otherwise differ from a TTS8000 or 8750.

Henry, I don't think your premise, in the above question, is necessarily correct.  GT2000s are not that expensive in Tokyo.  I don't know how the values compare to that of a TT101, but it's probably very close. In my opinion, both products are "sleepers", in terms of bang for the buck.  That said, I could be incorrect in my idea of relative values based on recent sales. I check Hi-fi-do and Top Class once in a while. GT2000s "seem" to be less rare than TT101s.  I've seen many for sale in Tokyo and almost no TT101s.  GT2000X is quite rare, based only on my observations over the last 5-6 years and several visits to Tokyo audio salons, whilst visiting our son who lives there. Interesting to note thanks to Hiho that the differences between GT2000 and GT2000X are much more than just adding a metal brace to the plinth.  Does the heftier bearing indicate also a more massive platter and also perhaps a more torque-y motor?

Can you clarify one thing: Is that Thuchan's plinth?  Cutting that shape out of slate is no mean feat.

So that brace is an option that would seem to fit both the GT2000 and the GT2000X.  I am sure it would help to reduce or eliminate colorations I associate with MDF plinths.  I'd consider it a sine qua non; I'd buy the reproduction, which is beautifully made, if I owned a GT2000.

Henry, You say above that GT2000s are often double the typical price of the GT1000, which would indicate the average price of a GT2000 is ~$2000US, based on your estimate of the value of a GT1000.  Then you say that a TT101 might go for $1500US (or Australian dollars, maybe?)  When you consider that the GT2000 comes complete with plinth and tonearm and that the TT101 is chassis only, I think the facts rather support my point that the two are not much different in current market value. 

I just checked Hifido; there are indeed "mountains" of GT750s and GT1000s for sale, and no GT2000.  There's a P3 for ~$5500US.

It's just how things go in the collector market.  Apparently, 2000Xs are right now highly desired in Asia.  If you really can buy a Mk3 for $5K on Yahoo Japan, you might grab it; they are worth a lot more, up to twice that much, in the US.  Many/most of the Mk3s I have seen on there have been in fairly ratty condition.

Peter, That would be a very low average price for any Mk3 that is in decent cosmetic and electrical shape.  Someone got a good deal.  Fully done Mk3's in a quality plinth have sold for more than $12K.  I paid more than $5K for mine with no plinth, about 6-7 years ago, albeit mine was NOS.  ("NOS" means very little, however, when you're talking about an electronic device that was sitting on a shelf for 30 or more years.  Although I got "like new" cosmetic appearance, I still had to go through the electricals, replace all caps, calibrate the drive system, etc.)  I nevertheless believe that this is a stone cold bargain, whenever I listen to my Mk3.

Belt drive?  We don' need no stinkin' belt drive!

Frank,
What’s your point?
The weekend that men landed on the moon, in 1969, my then wife and I were on the way to Martha’s Vineyard for a vacation. We had stopped in New Haven to visit my grandmother, and my wife would not leave until she could find a copy of that Sunday’s NYT: "Men Walk On Moon", it said. I was already an audiophile at that time, albeit with very little money to spend. I already knew then that I did not care for the Dyna PAS3X preamplifier.
Quartz resonates at a constant frequency. So, what is your point? Other crystalline materials could have been chosen by audio engineers, but quartz was chosen instead. By the way, quartz referencing did not come into the turntable world for a few more years after 1969.  Note that in the thread you cite, the ad for Technics talks about the original SP10 and the SL1100 and 1200.  The turntables in that ad did not use a quartz reference; that came along later with the SP10 Mk2, etc.  So, again, WTF?

I got riled up because I could perceive no "opinion" in the context of our first post.  In fact, I could perceive no point of view at all except to point out the fact that Quartz is an organic material.  Anyway, I do apologize for my tone.  I may have been too paranoid.  My father put together a nice monaural system for my mom, in the early 1950s, even though he had no particular interest in either music or audio electronics; she was an opera and classical music lover, however.  I grew up surrounded by her music and her singing; she was also an accomplished opera singer.  He built a cabinet for what must have been an Altec Lansing 604, and he bought a Harman Kardon Festival mono receiver. There was a Garrard record changer as a signal source.  By the 1960s, I was a jazz buff listening in college to whatever I could afford.

"Antique" systems are welcome here, as far as I am concerned, and I think I can speak for most others.  I've got a system based on Beveridge direct-drive electrostatics; Beveridge the company went out of business in 1982 or thereabouts.  It is fronted by a Quicksilver preamplifier that dates to the mid-1980s, and the phono source is either a Lenco idler-drive or a Victor TT101, both of which are early 1980s or earlier in the case of the Lenco.  The biggest, maybe the only, improvements in audio equipment since the 1980s, IMO, has to do with solid state gear, and only because of better transistors and ICs now available compared to "then".  CDPs are a whole lot better now than were the earliest products, IMO. Certainly, speaker design may be said to have gone down hill in many respects, even though the technology for making drivers has made advances in terms of computer-aided design (CAD) and 3D shaping.  Yet, I don't hear any miraculous new speakers these days, when I go to shows.

Problem with TT101 motor noise.  Dear brothers of the TT101, My unit was out of use for a few weeks, because our basement was flooded in a minor way during the last torrential rain in DC, and before that I was away at a meeting.  Yesterday, I fired it up and immediately heard a periodic rubbing noise coming from the motor.  My sense is that it comes from the top side, not from the bearing.  It can be heard once per revolution.  Today I took off the platter and loosened the motor mounts so I could pull it up and look at the mechanism from the side view without actually removing the motor from the chassis.  I can see no problem, nothing visual by side view of the intact motor. Yet when I spin the motor by hand with power off, I can hear the rubbing sound coming from somewhere within the mechanism, once per revolution, audible through about 30-40 degrees of the 360 degree rotation, rather on the high pitched side as rubs go.  Any ideas would be appreciated. Plus, I would like to know how to take the motor apart if necessary, so that I don't screw it up in the process.  I gather from appearances that the wiring harness that goes to the motor comes entirely from beneath the escutcheon on the upper level.  Thanks for help.

Thanks, Peter.  I have two questions: (1) Why would this condition have suddenly occurred.  Neither I nor anyone else has done anything to that slot-head screw that resides in the bottom of the bearing well, and (2) can you amplify on what part you refer to as "the top cover"?  If you are referring to the black protective cover that nests around the spindle and is held in place by 3 screws, I have taken that piece completely off, and the noise remains; in fact it's easier to hear it with the cover off. Thus I would tend to exonerate the cover.  Or have I got the wrong idea about what parts you are referring to?  Thanks again.

I just looked at the exploded view parts diagram on p. 28 of the Service Manual.  That black cover is not shown as a separate part; it's shown as part of the motor assembly, which is held in place by the 3 screws, parts #69 in the diagram.  That top piece of the motor case (painted black and inscribed in white lettering with some identifiers) is not involved in creating the rubbing sound I hear.

I think I am going to proceed first of all by changing the lubricant.  I have a 50W Redball (I think is the brand) synthetic motor oil that is recommended lubricant for the Kenwood L07D bearing.  Has anyone used that stuff in a TT101.  This WILL of course require unscrewing that plug at the bottom of the motor bearing well.  Any other tips are appreciated.

Banquo, In addition to adjusting the screw under the bearing well in order to set platter height, one can also shim the motor up, if the platter is rubbing on the escutcheon. I found on my TT101, in the course of investigating this new noise issue, that my motor is shimmed by two very thin washers under 2 of the 3 fastening screws. Under the third screw, there are 3 such washers (or shims). I demonstrated to my own satisfaction that they are all needed to help the platter clear the escutcheon with no rubbing. On that score, I know I wrote here that the noise I am hearing cannot be due to the platter rubbing. However, tonight the problem is behaving differently from yesterday. Now I do not hear the rubbing noise unless the platter and platter mat are installed. Gets louder when the weight of the mat is added to that of the platter alone. Yet, I can run a piece of paper all around the space between the platter and the chassis, and there is no evident point where the two come in contact. Thus it seems like weight pushing down on the spindle is eliciting noise from within the motor, whether it’s running or not. I can do a lube job, but it really does not seem to need it; it spins very freely. What a revolting development!!!

PS.  The synthetic motor lubricant recommended for the L07D bearing is Redline single grade, 50W, not whatever I wrote earlier.

Dear Peter,
I suppose we should take this discussion of my problem off line, since it IS rather boring to most.  However, I am grateful for your interest and your input.  The screw-in plug at the base of the bearing well on my unit is very firmly locked in or glued with some off-white substance that is hard enough to resist a screwdriver.  I have never touched the adjustment. Nor did JP when he worked on my turntable. It's quite possible I am looking at factory goop or their version of "loctite", applied more than 30 years ago. Further, the shims under the three screws that mount my motor in the chassis are also apparently factory original, and I have never had a problem with platter rubbing on the surround in the past.  JP reports the same, based on when he had my unit at his shop.  Further, further, two days ago, the rubbing noise was definitely, without a doubt, coming from within the motor assembly; I was able to reproduce it by holding the motor in one hand and hand-turning the spindle, whilst the platter sat off by itself on a shelf.  Last night I shimmed the motor up further so as to eliminate any chance that the noise was due to its rubbing on the surround, even though my common sense told me that this is not the problem.  The finding is that when the weight of the platter is on the spindle, the noise, although fainter than two days ago, becomes audible (last night).  When I add the SAEC platter mat, the rubbing noise gets a little louder.  Thus I can only think that the weights pushing down on the spindle are making the problem more audible, but the problem is probably not due to platter rubbing. Tonight I will investigate with my stethoscope to determine more accurately the source of the noise.  Finally, there is some advantage to my having gone to medical school; I own a good stethoscope.

Totem et al, I would not be surprised if wear on the thrust plate has everything to do with my problem.  Tonight I removed the motor entirely from the chassis.  Then with the motor on my workbench, I was indeed able to confirm my hypothesis that pressing on the spindle while spinning it could reproduce the rubbing noise.  With my stethoscope I can pretty much say for sure that the rubbing is NOT coming from the bearing per se, however.  It's coming from frictional contact between a circular gray metal disc at the top of the motor structure (the first thing you see if you remove the black motor cover) and the green circular PCB that lies directly underneath the gray disc.  The green PCB is fastened to a brass platform by 6 screws. I perceive that pulling up on the spindle also pulls up on the gray disc; they're attached as one piece.  This creates enough space between the gray disc and the green PCB such that the noise goes away entirely.  Thus, I think the "cure" for this is to gently turn the screw at the bottom of the bearing well in a clockwise direction so as to push up on the spindle, because of its contact with the thrust plate, and create enough space to cancel the rubbing.  Any comments on this idea would be appreciated; I am not sure of the function of the gray disc/green PCB arrangement.  However it seems they must together form some sort of sensor for speed, because the pieces are not nearly hefty enough to be the stator and rotor, which I can see reside on levels below this top tier.  If they are a sensor element, then I fear the possible problem that might arise from upsetting their spatial relationship.  I sent a photo to JP and Peter; I haven't the time right now to post the photo on the internet so I can cite it here.

At this point, I see no absolute need to mess with the lubricant. Unless someone has an opinion to the contrary and a reason to back it up.

rw and totem,
Last night I removed the screw cap on the bearing housing and inspected the bearing.  There is a very tiny dimple, probably about 1-2 millimeter in diameter, in the center of the teflon thrust plate, representing minimal wear after 30+ years, in my opinion.  The bearing itself looks OK without removing it, which I am loathe to do.  I will take a look at it with a magnifier to be sure it's ok.  The bearing oil looks only a little bit dirty. I wiped it out and soaked it up as much as I could with lens tissue, chosen for its lack of shredding, so it won't leave little shards of paper in the well. I will replace the original lube with either Technics oil which I ordered from KAB or Red Line 0W20 synthetic motor oil, the recommended lube for my L07D bearing.  I don't see any reason to change the thrust plate or the bearing itself, pending my close-up inspection of the latter. Then I will just screw in the cap a little farther than it was, so as to raise the spindle and the gray metal disc along with it, creating separation between it and the green PCB.  That's the plan.

Last night I changed the lube to Red Line 0W20, and everything seems good, once I fine tuned the adjustment of the screw cap. In my unit, there is a range of adjustment that is less than a quarter-turn (<90 degrees) between the unacceptable conditions of the gray disc rubbing against the top cover of the motor (spindle too high) and the gray disc rubbing against the PCB (spindle too low). Since the pitch of the thread in the cap is not steep, this seems too narrow for long term comfort, but we will see what transpires with continued use. I would rather not have to mess with the screw adjustment on a frequent basis.  I let everything settle overnight with platter, platter mat, and record weight in place over the spindle, before I will re-install the motor.  Just in case.

For what it’s worth, the platter definitely takes longer to coast to a stop with the Red Line oil in there than it did with the old factory oil. I’m not claiming that this matters at all.

Totem,
Yes, I thought about it. But the evidence of any wear at all on the thrust pad is so minimal (a dimple <2 mm in diameter and depth), that I thought the risk associated with removing the pad from the cap and flipping it over (associated with the evident difficulty in getting it out of the cap in order to flip it; it appears to be glued in place) was not worth the reward. I inspected the ball bearing under magnification last night and I don’t see any wear at all on it. I conclude that my bearing assembly is nicely broken in as is. If I flip the thrust pad, then the ball and pad would have to re-seat up against each other, which is akin to break-in all over again.

Did you remove the thrust pad in your unit?

Audiolabyrinth, The only question in your stream of consciousness post that I can answer is the last one; there is no "signal path" in a turntable per se.  However, the capacitors you will find inside the plinth are probably in association with the motor drive system, which I think would include a servo feedback circuit in the SL1600, about which I know very little. I am assuming it is kissing cousin to the SL1200, meaning at least that it is a direct-drive turntable, not a belt-drive.  Yes, it would be worthwhile to replace the electrolytic capacitors in this circuit.  Film capacitors in the circuit are probably still OK.  If you (or your wife) know how to solder, then just replace like for like, meaning replace the old capacitors with new ones of the same capacitance (expressed in microfarads and abbreviated "uF") and voltage rating.  You can buy the needed parts on-line from Mouser or Digikey.  Use Nichicon or ELNA Silmic brand electrolytics, or actually anything that those two companies sell.

I cannot resist asking how one goes about "hand picking" an audio component.  Listening is a better way to do it.  (Sorry, like I said, I could not resist.)  Sherwood did indeed make some fantastic receivers.

Can you say what is the composition of your $65,000 system? Why not integrate phono into that system?

"With an unsuspended mass-loaded turntable of any kind, that centrifugal force is absorbed and thus resisted by the mass of the supporting structure."  I don't want to say "I told you so", but I did tell you so back when that was a point of contention among us. Back when Raul was recommending just sitting the naked chassis on a set of AT pucks that were said to have magic powers.  And let me apologize in advance for being pedantic, but this is not a "centrifugal" force at all.  This is a force that is described in Newton's Third Law of Motion: "for every action, there is an equal and opposite reaction". Thus it is a force vector that has a direction described by an arc opposite to the direction of the arc of turntable rotation.  This is why and how the Kronos works; the lower platter, of mass equal to the working platter, is rotating opposite to the direction of the working platter. and this effectively cancels the forces. Otherwise, the tail wags the dog.

And finally, to be even more annoying, there is no such thing as a "centrifugal" force.  The force described in that commonly used misnomer is actually centripetal; to keep the object from flying off in a straight line, a force directed toward (not away from or "centrifugal") the center of rotation is generated and required.

Norm, A few questions:
When you press your ear to the platter mat, I presume that the platter is not rotating. Correct? (It would be quite a trick to put your ear down on the mat with the platter up to speed.)
The hum: is it a constant or intermittent?
You say the "wall voltage" measures 102-103 VAC.  I presume you mean this is at the output side of a 120 to 100V step-down transformer, if you live in the US or any other country with 120V standard.  If not, what?  
And in connection with the last question, are you sure your TT101 is set up to receive 100V? Most are, but at least a few (mine included) were sold with selectable taps on the power transformer primary such that one can feed the motor with 240, 120, or 100V.  Check that the wall voltage and the transformer voltages are copacetic.

I'll leave this to JP or someone else with more expertise, but I have to wonder whether using a power conditioner and not per se a step-down transformer could have anything to do with causing the hum that you perceive.  Obviously, yours is a standard 100V unit.

In the longer term, you would want to replace ALL the other electrolytics, as well as those on the Power Supply board.

Aaarrrggghhh. You’ve done it again, DDrive. Stop already with the "motor vibrations going up into the spindle". This is not really a problem with a direct-drive turntable. As I mentioned on the other thread, DDs are subject to bearing noise, just like any other type of turntable, and to EMI because the motor is close to the platter surface and thus relatively close to the transducer itself, compared to a belt-drive and some (not all) idlers. But DD's are not much subject to mechanical vibrations due to the motor, unless via a circuitous route via the chassis transmission of vibrations that in turn might reach the bearing.  The motor when producing torque also exerts a force on the chassis, opposite in direction to the force on the platter, which is why, maybe, DD's sound best with rather massive chassis'.

I also took a look at the Arche website; in my opinion, that platter mat is designed for belt-drive turntables, wherein motor vibration CAN in fact be transmitted into the platter via the belt making contact with the rim. The most it can do for a DD turntable is to improve isolation of the LP from bearing noise or vibration, if that is a problem. I guess also that by the mere fact of elevating the LP further away from the motor, it might also diminish any EMI effects from the motor. Perhaps this has something to do with why it sounds very good on your turntable. However, I do not detect that EMI is a problem with my SP10 Mk3, although I have never measured the field strength at the platter surface. As you know, the Mk3 platter is quite thick and constructed of alu, stainless, and what I think is brass or bronze, all of which make for a pretty good EMI shielding effect.

I can’t resist correcting Dover, because the opportunity to do so is rare. The force that keeps a body in orbit is by convention referred to as a "centripetal force", because it is literally "center-seeking". Think about a biblical type of sling shot. When you spin it around over your head, you are applying a force that keeps the projectile in the sling from flying off in a straight line tangent to the orbit. That force has a vector direction toward the center of rotation, your hand. I actually do not know where we got the term "centrifugal", but it is clearly a misnomer. What we think of as centrifugal force is really inertia, the tendency of a body in motion to continue in motion in a straight line, unless acted upon by an outside force. Inertia is observed as the result of the absence of a force.  Centripetal force is applied via the sling to counter-act the inertia of the stone or other projectile in the pocket of the sling. 

Geoff, I would have thought that "EMI absorption" is but a more concise term for "low frequency magnetic field absorption".  Especially since my reading also tells me that the forte of mu metal as a shield is to block or contain EMI, rather than RFI.  As I understand it, mu metal is not much good with RFI.  Please correct me, if I am off base here.  

L07D owners, including me, espouse the use of a shield between its platter and the stainless steel "platter sheet", which seems to be Kenwood's term for "mat".  For a few years, I used TI Shield, when it was available from M Percy, in this application, and I reported that it did some audible good.  Then I bought an Ortofon MC2000 cartridge and mounted it on my L07D.  I immediately noted that the rotor of the L07D motor, being itself a large magnet, induced magnetism in the TI Shield, which in turn sucked my MC2000 down on to the platter, nearly collapsing its suspension, a very very bad thing.  This observation forced me to remove the TI Shield from the sandwich, and I have lived without it since then.  Apparently the placement of the magnets in the MC2000 (and maybe other Ortofon LOMC cartridges) makes it uniquely susceptible to this problem, because I never had experienced it previously with any other brand or type of cartridge.  I know that Dave Garretson used ERS cloth on his L07D platter, instead of TI Shield, and I wonder whether ERS cloth would produce the same induced magnet problem, probably not.  However, I always thought that ERS cloth might have the negative effect of impeding energy transfer between the platter sheet and the platter, on an L07D, which is why I have not tried it up to now.  Any comments appreciated.  ERS is not quite as good a shield as was TI Shield, as far as I can learn from my reading. (It's a very complex subject.)

On my TT101, I use an SAEC SS300 mat that was hanging around the house, which I tell myself adds some shielding effect between motor and LP surface.  I am using an Acutex LPM320III cartridge in an FR64S, on the TT101, and I perceive no problem that could be ascribed to EMI or RFI, so I don't worry about it.  In fact, that combo is sooooo surprisingly good that I am loathe to experiment further.

Geoff, I will have to chew on that mouthful for a bit, but can we agree that EMI has the property of "frequency"?  Assuming you would agree, then in what way would EMI differ from "low frequency magnetic field(s)"?  Permanent magnets per se do not exhibit the property of "frequency"; you need a coil AND a permanent magnet and relative movement between the two, to generate a pulsatile field.  At least, that's my story.

Thanks for your note regarding the special dangers associated with using the MC2000, Raul.  I neglected to mention that the TI Shield contains iron.  After observing the problem with the MC2000, I was able to demonstrate to my own satisfaction that the permanent magnet rotor of the L07D motor was actually inducing a magnetic field in the TI Shield, which made matters much worse.  Without the TI Shield, there is no problem, and I am able to run the MC2000 on the L07D.  It would seem that coreless turntable motors, all based on the original Dual design, generate a magnetic field and EMI that is 90 degrees different in direction (i.e., in the vertical plane rather than in the horizontal), compared with the fields generated by typical iron core motors, because of the orientation of the stator and rotor.  So, one has to be careful with them. On the other hand, my current feeling is that coreless motors are to be preferred in a DD design, for best sonics.

So, Totem, are you going to take the plunge, or not?

Dear Totem, I was unaware that you already own a TT101. One is enough for most of us.  I bought mine in context with a QL10.  Thus, I got a UA7045 plus the QL10 plinth, which probably has its own unique part number.  Having already commissioned the creation of four different slate or partly slate plinths in my audio life (for Lenco, SP10 Mk2, Mk3, and Denon DP80, respectively), I was loathe to go through that process again.  Plus, I was for 2-3 years uncertain that my TT101 would ever function properly, until I found JP Jones on another website. So, what I did was to re-enforce the QL10 plinth with one-inch thick pieces of aluminum that pretty much cover the available space flanking the hole in the plinth that accommodates the turntable chassis; I bolted them to the wood laminate very firmly, to create a CLD effect.  Then I ditched the stock MDF armboard in favor of a machined piece of aluminum that exactly fits the rectangular space in the plinth; this alu armboard is in turn firmly connected to a second piece of aluminum running below it under the wood plinth proper.  This seems to work quite well to create a very neutral chassis for minimal cost.  If I knew how to post photos here, I would.

I use an SAEC SS300 mat on my TT101.  Mainly because it was sitting around unused.  Tonearm is FR64S with B60 base.  So, perhaps my tinkering days are over.  I put this all together as described. It's sounding great with an Acutex LPM320 cartridge, and I am not inclined to mess around with the package.  Even though another mat might sound a little better.  Even though the mating of the Acutex with the FR64S might seem to be a mismatch.

Is there any feedback here on the UA7045? Is its effective mass really so low as claimed by one source?

Halcro was/is very clever at posting his photos on one of the on-line websites and then quoting the URL here.  Others have done the same. Probably that is what we should do too.  Or one could possibly put the photos on the System page here on Audiogon; I tried that a few months ago but could not make it work.  I already do have some old photos up there.

Yes, UA7045 is 9-incher.  There is also a 12-inch version with a different numeric designation, maybe 7085, as you suggest.  Someone on the Analog Forum mentioned that the 7045 has a relatively low effective mass, suitable for high compliance cartridges.

Artisan Fidelity make some beautiful stuff, so I imagine your plinth is quite nice. PBNs plinths for Denons are fantastic too.  

Congratulations, JP.  Perhaps having my TT101 in your shop had something to do with your pursuing the new purchase.  So far as I can tell, the finish on your escutcheon (the decorative rim that shows above the plinth and bears the switch panel) is the same as on mine.  Yes?
I'll check my SN and report it here.  

My TT101 was an "export" version, in that it can be adapted to work on 100V, 120V, or 220V, by selecting among power transformer primary windings.  I read that these were sold to US service men stationed in Japan, probably among many others who needed other than 100VAC.
Although my TT101 was not NOS, it obviously had had very little use prior to my purchase of it.  Possibly this is because the tiny crack in the PCB, that was causing it to fail intermittently, plagued all previous owners, as well as me, until JP identified the problem and repaired it.

I was in NYC for Thanksgiving and several days thereafter, and I thought about bringing you (JP) my SP10 Mk3 PS, so you could install your chip and re-calibrate it, but in the final analysis I figured it was best to send you the PS, when the time comes.  Meantime, I have no problems with the Mk3.

I now realize that you guys may be referring to the area UNDER the platter.  Yes, mine is painted in that area.  Only the exposed outer rim of the circular escutcheon is brushed alu or chrome or whatever.

I remember going to visit Julius Futterman, in 1979, in his 2-room factory just off Broadway on 72nd St.  There to pick up my new pair of H3aa amplifiers.  I envision you toiling away in a similar space.  I'm from New Haven, by the way.

I'd never give up my L07D.  How does the PS-X9 stack up among these great DD turntables?

Best-groove, I don't know if you were referring to me having both a Mk2 and Mk3, but I sold off my Mk2 when I bought the Mk3.  I don't own a Mk2.  I do own a Denon DP80.

I responded to K's post over on his own thread.  Suffice to say I too am very grateful to JP, for his work on my TT101 and eventually for replacing the so far no problem MN6042 in my Mk3 with his discrete circuit.  I've posted here on my interaction with JP in the past.

Halcro, I am not sure what you are reporting.  Do you perceive that your TT81 outperforms the TT101, compared even to how the TT101 sounded before the power outage? Or are you saying that this observation is in relation to how the TT101 performed AFTER the power outage?

Were you able to ascertain the cause of the momentary loss of power on your street? Assuming this was not the moment when Trump hung up on your Prime Minister (a moment of which I am thoroughly ashamed and disgusted), perhaps it was a lightning strike.  Lightning is at millions of volts and can, for a brief instant, get by just about any power conditioner or filter. Perhaps, if the TT101 power supply was thus damaged, this could account for your perception. You may want to check or have someone else check the rectifiers and the filter capacitors in the TT101 Power Supply. For that matter, damage may also have been done to the downstream circuitry.

Have you ever changed the bearing lube in your TT101 (or TT81)? Yes, Victor wrote that the bearing never needs service, but as we've said before, "never" has a new definition at the 35-year mark in age. I changed my lube to Redball 0W20 motor oil, and I like the result.

I suppose a given TT81 could outperform (in terms of human perception) a TT101, but in principle a coreless motor is just better for turntables, in my opinion.

No, SP10 Mk3 is not coreless. It's a massive 24-pole motor.  I never heard any "problem" with it, but it definitely sounds more coherent, musical, or smooth (pick your adjective) after having undergone the Krebs mod, which is directed at the tendency of the rotor/stator structure to rotate counter to the direction of the application of torque (Newton's 3rd Law), which in turn causes the servo to make more frequent minute speed corrections than is necessary and maybe that introduces a tiny bit of roughness or edginess to the sound that is effectively ameliorated by whatever Richard has invented. (It's a state secret.)  The Krebs Mk3 is by far the best of the iron pole motors I have heard in this system and probably edges out the others as well, if I were ever to do a really intense comparison.  JP Jones has a further upgrade for the electronics of the MK3 that I plan to have him do on mine. (Fidelis Analog, on the internet)

Your TT101 may need to be properly calibrated.  JP, who also fixed my TT101, raising it up from doorstop to turntable, says that calibrating the TT101 is a bit tricky.  I think it's fair to say that he would say most vintage direct-drives still in use are not working as well as they could, because of lack of proper calibration of the drive electronics.  Just a thought.

Downunder, My Mk3 is mounted in a 70-lb slate slab, 2.5 inches thick.  The slab is mated to a solid cherry base that is about the same size as the slate.  I epoxy'd some threaded inserts into the slate and bolted the wood base into those, for good Constrained Layer Damping.  Then I made some slate armboards for this plinth.  The 10.5-inch Reed 2A tonearm (Red Cedar wand) is mounted on a slate arm board which is also bolted into the slate slab.  The whole thing probably weighs about 100 lbs. In order to maneuver it so I could get some home -made footers under it (and some Stillpoints), I placed a deflated inner tube under the plinth and then inflated it, so as to raise up the structure.  Lifting it and then simultaneously putting something under it was a non-starter. It sits atop an Adona rack.  I use a Boston Audio Mat2.  There may or may not be a photo on my system site.

Sorry about mis-counting the poles on a Mk3 motor.  I was going on memory, as I was not about to take the platter off just to count the poles.

Forgot to mention that I built a bearing damper exactly like Albert Porter's idea, into the cherry base of the above plinth.  Albert uses a block of iron.  I am leery of putting that much iron near the motor's rotor, which in the Mk3 is a gigantic circular magnet bolted onto the underside of the platter.  So I used a brass block of similar dimensions and mass.  A threaded brass rod perforates the brass block and makes contact at its upper end with the bearing housing.  Albert uses this idea in his Panzerholz plinths, assuming he still makes them.  I just snug the brass rod up against the bearing assembly; not too tight, just snug.  

Thanks, brf.

The Mk3 is king of pace and rhythm, not at the expense of sounding too "tight", for want of a better word.  Originally, without the Krebs mod, I would say it did sound a little tight, compared to the L07D.  Someone else might prefer the more languid sound of the L07D, and I certainly like that, too.  I recently mounted a ZYX Universe cartridge on the Reed, purchased from one of our brethren here.  I was primed to love the Universe, based on hearing it at the home of my neighbor up the street, who has since moved on to a Universe Premium (or whatever they call the 3rd generation of the Uni). I thought then that it was the best MC I had ever heard.  (He was using a Galibier turntable with a Talea 2 tonearm back then, now uses a Telos.) I am loving the UNI on the Mk3, too. Yes, there are two crazy audiophiles within less than a quarter of a mile of each other on my block.

I’ll take "...languid with happiness" from your dictionary. I love the L07D. Note that I wrote "more languid", compared to the Mk3, which is anything but languid.  I was also trying to stay away from saying the L07D was "more musical".  Before the Krebs mod to the Mk3, I might have said that. Language is always a major limitation in trying to verbalize the amazingly sensitive discriminatory powers of the ear/brain.

Shane, Always willing to take the P3 off your hands.... (To answer Henry's question, a man always needs "one more" turntable.)

Henry, I am loving the ZYX UNI on the above described Mk3. All my LPs sound better than ever. Did you ever audition the UNI II or the latest new version of the UNI? My prior favorable experience with the UNI was with the original version, which led me to be interested in yours. I was not prepared to buy into the idea that newer versions are necessarily better. In particular, the latest one I think has a carbon fiber (or some such) cantilever, which could not possibly have the same sonic flavor as did the original.

Raul, I think JP already pointed out to you that it is folly to judge any two closely matched turntables in general by factory published specifications, because we don't know how the measurements were made. In particular, we do know that the P3a specs were determined after there was a revision in the methods for measuring S/N that made everything look better (quieter by I think about 3db) than it did before the change in methodology.  

On the other hand, I do agree with you; the P3 or P3a may well be superior to the Mk3, but not based on the differences in factory published specifications.  However, I would posit that the Mk3 offers more possibilities for upgrades that might bridge any gap between it and the P3, because of its more modular construction.  I don't deny that I would like to own a P3, in order to hear it for myself in my system and decide for myself where it stands in the pantheon of high end DD turntables.  I suspect its plinth is not up to modern standards, although everything else about it apparently is.

Of course, this is coming from an uninformed philistine who cannot tell music from distortions.

Shane, Yes, I am aware of its internal construction.  Just wondering whether the wood outer "box" that serves only as a cosmetic shroud might resonate a bit.  (Even if so, I imagine you could just remove it entirely.) Also, I gather from a person who lived in Tokyo and owned two P3s at one point that it is a good idea to get the suspension serviced by a Pioneer authorized technician.

War of the coreless motors: P3 vs GT2000X vs L07D.  My money is on Godzilla.

Shane, I was wondering about those buttons, if one were to remove the wood casing.  You could probably make some sort of rigid platform to re-mount them in place of the wood.

To say that the P3 suspension, which looks like that of a modern sports car in terms of complexity, is not like an LP12 suspension, is pretty much like saying that a modern sports car suspension is more sophisticated than that of a Model T Ford. It's no contest.

Thekong, You wrote, ..."if that is true, and the DP100M is in the same league as the SP10MK3, P3a etc.,"

That's one of the biggest "ifs" I have seen on this thread. First of all, Dover does not say what tonearm and cartridge were used to make the comparison of the DP100M to the Final.  Second, with all due respect to Dover, he is passionately in love with his Final (which is fine with me), but he does tend to try to prove its wonderfulness by verbal argument (which is hearsay evidence at best, IMO).  And third, I certainly don't think any of the aforementioned direct drive turntables is perfect, but, as you said too, these particular criticisms would not seem to apply to well set-up, properly restored and calibrated examples of the breed, no matter what. In fact, it's almost a list of why I prefer DD turntables I have kept in my system to belt-drive turntables I have tried and rejected.  On the other hand, Dover is the only person I know who has ever had a Final tt in his system; we cannot really know how a Final would stack up.  In sum, we don't have enough data to agree or disagree with Dover.  I personally do not at all care for the Denon DA307 tonearm, as supplied with the DP80 turntable. I don't know what tonearm is supplied on the DP100M, but if it is close cousin to the DA307, all bets are off.  Lack of focus and compressed dynamic range are, IMO, possible descriptions of the DA307.

I agree with Henry.  That arm looks special for the SL1000Mk3, with its broad and wide base.  The wand looks like one of the optional wands for a B500 base, but the base is different, as noted.  Very desirable tonearm, I think. Looks to be low effective mass, too. Thanks for posting the photo, Shane.

What I find to be especially interesting about that tonearm (EPA100Mk2, according to others) is its base structure.  From the photo, it seems to be one continuous piece that broadens out to cover the entire arm board.  Is that the case, or are we looking at a separate escutcheon into which the base of the tonearm sits?  If it's all one piece, that would provide a nice "sink" for energy generated in the arm wand. Reminds me a bit of the modern Durand Telos (big money), but I would bet that if it were possible to do a head to head, the Technics would be superior.