Vintage DD turntables. Are we living dangerously?


I have just acquired a 32 year old JVC/Victor TT-101 DD turntable after having its lesser brother, the TT-81 for the last year.
TT-101
This is one of the great DD designs made at a time when the giant Japanese electronics companies like Technics, Denon, JVC/Victor and Pioneer could pour millions of dollars into 'flagship' models to 'enhance' their lower range models which often sold in the millions.
Because of their complexity however.......if they malfunction.....parts are 'unobtanium'....and they often cannot be repaired.
128x128halcro
We threw out all of the electronics on the SP10 MK2 and built a completely new motor control and power supply for our Tourmaline turntable which uses the SP10 motor/platter.

Losing all of the PLL Servo components is a very good thing from a sonic standpoint.

Jonathan Weiss
OMA
I emailed 4 techs about my problem and after initial confidence and enthusiasm they've backed off--after I sent them the service manual.

I snooped around and googled some of the IC part numbers, and all the ones I looked up are available from various sources. So, evidently they are not unobtainium.

What appears to be unobtainium is a tech who can do the job and do so without asking for an arm and a leg.

On a brighter note, the hunk of turntable I have does look nice in my office.
I'm wondering what Bill Thalmann said?
He is supposed to be the guru for SP10s and it would surprise me if he thought the TT-101 was 'over his head'?
Bill knows the sp10 circuit but he's unfamiliar with the Victor. Consequently, it would take him far longer to diagnose a problem with the latter. And since time is money, he told me he couldn't afford the time it would take to fix it. This suggests it is fixable, but just not by him given his constraints.

To live less dangerously, we need to find a hobbyist with time on his hands. I imagine a person like the one who runs the Kenwood l07d site but with a Victor emphasis would be perfect.
Atma-Sphere (alias Ralph)
I knew this guy that used a pigskin platter pad... he would buy *raw* pigskin at the local slaughterhouse, cut it out and kept the thing in a jar in the 'fridge when not in use, until the bacteria got to it... the LPs tended to get greasy and smelled like bacon.

The idea is that it was 'natural'- natural sound, get it? The slaughterhouse stopped selling to him when they found out what he was up to...

I do that too but only use the special "bacon mat" when playing Pink Floyd, "Pigs On The Wing."

Otherwise it goes back in the frig...
I want to resurrect this thread with a resurrection story.

I told my story of woe above and the table has just been sitting on a cabinet since last August mocking me. I was going to sell it for parts but on a whim I decided to plug it in and leave the power on overnight. I recalled that my sp10, when it was acting up, would benefit from being left on, so I thought why not try it with the victor.

Lo and behold the following morning I pushed start and it remained running for a good long time--something it had never done, as it had the habit of stopping the platter after 30 seconds or so. After some fits in the next couple of hours it maintained perfect speed for 8 hours. It's the first time it's played music since I bought it last June. I heard its glory for those 8 hours last night! This is one fine tt.

A guy from Portland with whom I had emailing about the table suggests that it might be the capacitors reforming after long storage. Seems plausible.

All is not perfect however. This morning it reverted to its old ways for a couple of hours. It's now running again perfectly, so who knows what's going on. One thing that could be the problem is the electronic braking function: it doesn't always engage.

I feel like I'm living on borrowed time. I'm taking it to a tech soon to have the power supply capacitors replaced and the braking circuit examined. Mercifully it doesn't appear to involve the speed circuitry.

Now back to the music.

Greetings Banquo,
Signs of life??.......that sounds hopeful.
Did you form any meaningful impressions in the time you were able to listen?

Good luck from hereon in.
I would surmise that Mahler's Symphony No2 would sound very good on Banquo's Victor.
Banquo and other TT-101 owners. Don't know why, but when my TT-101 is recalcitrant about getting started after a day off, I turn on the power and spin the platter by hand backwards (just get it going fast and let it spin down). It then is ready to play on.

Glad to hear that you are getting to hear this beauty. I don't recall if you are using it nude or not but either way, enjoy.
Dear Banquo, Based on your recent experience, it is possible that you have not yet fried irreplaceable parts or circuitry that is inscrutable to even Bill Thalmann. So it could not hurt and might help a lot if you just have someone remove and replace ALL the electrolytic capacitors. Bill is probably tired of spending most of his time repairing direct-drive turntables. If you can dig up a schematic or a service manual, you might eventually arouse his interest. You might try a Japanese source. But meantime, my advice is do the lytic caps; it is probably necessary and certainly cannot hurt. The parts cost will be well under $50.

Even Howard Stearn, the guy who runs the L07D website, has given up on repairing and restoring L07D's. I think my second one was the last that he was willing to do. He's an orthopedic surgeon by day, so one wonders why he ever got into it in the first place. There's more money in hip replacements.
hi guys: the resurrection persists. Started up just fine this morning. I'm going to take Lew's advice and replace the caps. There's a boat load of them in this monster though, so replacing all of them may be cost prohibitive in terms of tech time. A quick peek at the service manual shows over 50 caps in the servo board alone. So, maybe just the ones in the power supply and then others upon visual inspection?

No meaningful impressions yet, Halcro. I'm using a new cart (astatic mf 200) so it's difficult to know what's responsible for what. Once the dust settles, I'll put on a cart I'm more familiar with and make a judgment. The combo sounded mighty fine last night though, better than anything I recall the sp10 putting out.

Yes, Aigenga, nude she is. I have the ql-10 plinth but what's the point?

I love Mahler, Dover, but for some reason I don't own the 2nd on vinyl. It'll make the resurrection complete once I get a copy and spin it on the victor?
You have to ask yourself what is the cost of "tech time" as compared to the value and rarity of a TT101 and the pleasure you derive from it. But meantime, you can order the capacitors from Mouser or Digikey on-line (assuming you live in the USA). I recommend Panasonic or Nichicon brand. Dirt cheap compared to the consequences of not doing it. Once you have the parts, you might take it to a technician and get an estimate of labor cost. I would be surprised if it would take much more than 2 hours to do them all. I would offer to do the work myself, except..... I won't. The other side of this coin is that you may not be getting the best out of your unit at present, even if it "works", due to a few bad capacitors. (Last time I looked, DD turntables were not generally designed to require a push-start in counter-clockwise or clockwise direction.)
I would offer to do the work myself, except..... I won't.

Dear Lewm, this reminds me of what I used to say to students who asked for regrades of essays: "I would regrade your paper but I have a rule according to which I don't regrade papers."

You offer sage advice regarding comparative value. I'll keep it in mind when I hear the undoubtedly large number coming out of my tech's mouth.
Let's say, at most he needs 3 hours. (I am fairly sure I could do it myself in less than 3 hours, and I know good techs are faster, neater, and better than I.) Let's say he charges $80 per hour. (I have no idea what they charge these days.) The capacitors might cost $30-$40, if that much. So you are talking around $300 for peace of mind and probably improved performance. One of those "no-brainers".
You forgot to include the 'extra overcharge' and 'special undercoating' (seinfeld reference).

I was quoted a much higher number by a very reputable tech to do the same on my less complicated sp10 mk2.

But if that's the number, to be sure I would jump at it.
Dear Banquo, You could perform the work yourself. Watch a Youtube on desoldering and resolding. You will get great satisfaction doing it yourself. I fine-tip soldering iron only costs about $20 and desoldering braid about $5.
If you do it yourself, which I endorse also, it is worthwhile to invest in a "solder station". This is essentially a soldering iron with feedback, so it maintains a constant temperature, which you can set on a dial control. They cost more like $50 to $100 but a good one lasts forever and you can use it for other minor repairs in future.

Was the "reputable tech" named Bill Thalmann? If so, Bill would do much more than just R&R the caps, which is probably why his estimate seemed high, if it was Bill (but you already told us that Bill declined the job, so maybe not Bill).
Thanks for your confidence in my abilities, redglobe, but even with a very generous conception of possibility, I'm not sure I can envision a world in which "You could perform the work yourself" is true of me. I tried to make interconnects once and all I managed to do was melt the pins of the connectors. If I were to try again, I would certainly take Lew's advice and get a decent station as my previous disaster was not all user error (I want to believe).

Yes, Lew, it was Bill and it was a quote for my technics and not the victor. It did include other things but since I didn't ask for those other things, I assumed it all came as a package. No matter. He fixed the technics w/o recapping and did so for a reasonable price, so I'm not complaining (quite the opposite in that case).
Resurrection complete.

After nearly a year of fruitless search for someone to fix my ailing Victor tt 101, I found the man of my audio dreams. His name is Dave Brown. I must have emailed 20-30 odd turntable repair shops and/or persons and had nothing to show for it until I found Dave’s cool website. He specializes in synthesizers (I think), but he’s a pro in the highest sense of the word, and took ‘all of’ 7 hours to diagnose and fix what others said was unfixable or too time consuming. He had never seen this turntable before, yet with service manual in hand he was able to do what seemed to me, and not just me, impossible. And yet he’s not a pro in the sense that he runs a shop (he used to, I believe); he now does repairs out of interest and by request only. He initially declined, citing the difficulty of accessing the victor’s circuit boards while powering the motor (a well grounded concern it turns out), but I’m a good beggar ☺.

On my understanding of what he told me, the boards used on the victor are ‘eyelet boards’. The solder connections through such boards tended to suffer cracking. This is what happened to mine. Some of the connections are heat sensitive, and that’s why I experienced the partial resurrection a few weeks back after leaving the unit on. The cracking is not necessarily evident to the naked eye, but after resoldering the boards, the table now works flawlessly. It should be noted that changing the power supply capacitors didn’t fix any of my troubles, but some of them appeared to be leaking so it was a good idea to do so.

He warns that not all is repairable: if the quartz clock responsible for the pitch control is broken, then most likely you have a doorstop.

So, in regards to that, there is some danger in living with this direct drive table, but the world is made less dangerous with Dave in it.

Gotta go find that Mahler now.
JVC QL-10
Someone in the US got lucky today.
Hopefully he might contribute here?
This one looks like a beauty?
Banquo, If, God forbid, you ever do have a problem with the quartz clock or any other unobtainium ICs that may be lurking in the circuit, you are not necessarily out of luck. If Victor was anything like Technics, you will find that some of the individual parts of this type were also used in lesser models, often available at much lower cost vs the TT101. Thus you can probably find a lower level Victor to use as a parts mule for your TT101, if push comes to shove.

Henry, This time I emphatically agree with you; someone got a steal on that TT101.
Dear Lewm: Yes, that JVC one was an steal at that price not only because the DD TT but because comes with a great JVC tonearm performer ( I own it . ).

If you read that ebay auction the seller gives almost no importance to the tonearm atacchen/mounted. Certainly he needs the money or his knowledge level about is " poor ".

I was looking for that JVC tonearm in the past, not very hard to find out, and suddenly I seen an ebay auction at very low price for a JVC TT that came with that tonearm and the JVC DD TT-71 ( great performer too, even the 101 and surpass the 801. ) and as here the seller ad was really for the TT so I bought it and now I can enjoy two great JVC items.

The tonearm is higly recomend.

Btw, for those that wants to have the DD naked experience and can't find out the JVC TT-101 or is expensive the TT-71 JVC option is something to experience and more easy to get.

Of course that the Denon DP-75 and DP-80 options are good ones too and at least at the same JVC TT-101 level but more easy to find out and I can tell you that through so many years using my Denon's I never had any single trouble about and knowing Denon I think ( I can't besure because I never had a problem. ) could be easy to find out TT parts to fix it in case a trouble with.

About the JVC TT-101 there are some parts in its design that are not shared in its down line brothers because it's an improved design. With Technics and Denon things are a little more " easy ".

Regards and enjoy the music,
R.
Dear Raul,
I've also heard good comments on that JVC arm.
The plinth for the QL-10 is also a cut above the average.....although the armboard does not look like it would suit a 12" arm?
Time to go 'nude' methinks?!

Regards
NO!! Those of us who choose to buy vintage gear know the risks and if that is living dangerously...then so be it.

I purchased a mint 1 owner Denon DP-45F Direct Drive TT - locally in my home city. So I avoided the potential pitfalls of shipping a TT. Then I got a sense of the owner - pride of owning his equipment, etc.

I know that these Denons have microprocessors/capacitors - that if they fail....there can be trouble. I took a chance. After I purchased it I took it to a reputable electronics repair shop in the city and asked him to give the TT a thorough going over, make any necessary adjustments and replace anything that needed replacing.

He called and told me the deck was as clean on the inside as it was on the outside / that the main capacitors had already been replaced with quality parts / and that except for a minor adjustment or two the TT was good to go, and likely for many more years. He installed the new cart and I have been in vinyl-spinning bliss since.

The TT works flawlessly. Could it "die" anytime? Sure, but so can any modern TT. And there are more spare parts for old TT's then many people know. My tech (who owns the company and has for 30 years) says you'd be surprised what he can come up with (parts) and find somewhere in the world if he has to.

For those of us that like vintage, we take on those risks - knowingly.

Living on the edge!

Good listening,

cat9
Cat9, Capacitors are cheap, available, and better than ever. That's why I repeat ad nauseam that one ought to routinely replace electrolytic capacitors in the circuits of these old DD turntables, because failure of one of them can lead to destruction of a "microprocessor" that might be unobtainium. (In fact, your DP45 probably has only one IC, at most, but it controls major aspects of tt function. I found 3-4 years ago that it was not unobtainable, if one does a parts search on Google. I don't know whether it's still buy-able.) There are several discrete transistors in the Denon DD turntable circuits; all of those are either available or replaced by better versions. You will have no problems replacing the discrete transistors, if needed. It's that single IC you need to worry about.
I've got two spares for my Denon DP80, but I believe it is not the same IC as what was used in most of the other models. If the caps are kept tip-top, and if one does not plug a 100V Denon into a 115V AC outlet, all should be well. (I am pretty sure someone who owned it before me blew the IC in my DP80 by doing that. Or, as he told me, "we always plugged it into the wall directly with no problems". This means that since the turntable continued to rotate, there could not be a problem. No matter that it was off speed and that the strobe light no longer functioned as a strobe.)
To avoid hijacking Peterayer's Timeline Thread any longer.......I thought that we could post our recent travails with our vintage DD turntables in this more appropriate Thread......

Lewm has had a litany of problems with his TT-101, but has recently had it running more or less correctly at his home.

My Victor TT-101 began misbehaving about a month ago and whilst it was at the Technician's for a complete rebuild......I had my back-up TT-81 to play with.
Here are the innards of the TT-81 which is quite a bit different to that of the TT-101.
Another view of the TT-81 showing the single-sided PCB compared to the stack double-sided PCBs of the TT-101.

Today I picked up my TT-101 after the replacement of every single capacitor and the removal and replacement of all solder points and joints (thanks Banquo).
In other words....it has been completely rebuilt!
The most difficult problem apparently....was diagnosing and repairing the intermittently malfunctioning Power switch.
The switch works by way of a circular 'gear drive' which moves one position at each click which in turn activates the actual switch??
Why they design it this way is a mystery to me.....but after lubricating the gear drive and still finding the fault via a 'spark' from the switch......the Tech replaced the switch.
I have had one listening session today...and so far so good......:-)
I'm glad it worked out for you, Halcro. The good news for us is that you now believe the much more widely available tt 81 is just as good?

There appears to be some disagreement regarding whether the tt 81 has a coreless motor or not. The vintage knob asserts that it does, but 'caligari' on this thread says he's positive that it does not. If he's right, then I assume the two tables would sound different? Did you notice that? I'm asking because I wouldn't mind getting a back-up. Nearly every time I push play on my 101, I feel a touch of anxiety; how's that for living dangerously?
OK...let's try this again.....
TT-101
TT-81
TT-81
Yes Banquo......the TT-81 is a stunning performer as well....although I need to now listen to the differences with my 'new' rebuilt TT-101?
Initial impressions are that the 'old' TT-101 had suffered audibly before its demise and the 'new' TT-101 appears to be a 'new' animal?

I think that the information from Caligari about the motor differences may be correct as the Service Manual for the TT-81 specifies the motor as "DC Servomotor" whilst the TT-101 manual specifies "Coreless DC servomotor".......

I could happily live with the TT-81 nevertheless.....
I have been liaising with a keen audiophile in Crete by the name of Antonis who has designed and assembled a 'sprung platform base' for the 'nude' mounting of his TT-81
I think he has done a marvellous job and his solution certainly addresses Lew's concerns regarding the armpods and turntable relationships....?
The 'Movement' appears to be gaining strength? :-)
Thanks for the links, Halcro. The boards of your 101 look immaculate. Did you relube the bearing?

Antonis's design sort of looks like what Ct0517 has done with his sp10. He also advocates bolting down the footers. What materials does he use? Slate, granite, marble: I can't tell.
Thanks Banquo,
I think my whole TT-101 is in amazing condition.
I counted up in the manual.....and there are 90 capacitors and my Tech replaced them all.......
He said that when he removed all the old solder joints.....there was so much black smoke in his workshop...that his wife thought the place was on fire :^)
He seems to have done a great job of re-building the deck...and he is young, talented and thorough....so it bodes well for the future?
Perhaps we aren't living dangerously...as long as there are good Techs around?

I didn't have the bearing re-lubed as the manual says it is sealed and never needs it. The platter turns so freely and is totally noiseless.....so if it ain't broke....?

Antonis' sprung bases appear to be 1" thick granite slabs with stainless steel and/or aluminium sheets laminated top and bottom in an attempt at creating Constrained Layer Damping.....however, I think he may have erred in his understanding of the principles?
Had he placed the aluminium sheet between two slabs of 1/2" granite with joint adhesive of viscoelastic consistency.....it may perform better.
Alternatively a material like plywood between the granite sheets seems a better choice as metal sheeting shares many of the same acoustic properties of stone?
The supports for his TT-81 and for the tonearm pods are solid stainless steel rods but the interesting choice appears to be that of the turntable supporting ring which I simply can't make out?
I'll have to ask him.....
I'm sure it sounds fabulous and he seems to confirm that at the first few listens....
10-13-11: Halcro:
"Doesn't it seem odd....if a coreless DC motor produces no cogging and sounds so 'fluid', relaxed and unfazed.....that a manufacturer would be foolish to even contemplate an alternative design?"

You look at the release of the models chronologically, then you realize all coreless motor models came out in latter days. Once they went coreless, they stayed coreless. This is the same trend in other brands such as Kenwood, Yamaha, Pioneer, Sony, Sansui, etc...

As far as I remember, the only two major brands stubbornly stayed with non-coreless motor was Denon who kept using their induction motor through out and Technics.

Pioneer's top of the line model was the P3 and latter P3a (linear motor). It was not coreless motor but it was too popular in the market place and too developed to change such flagship model. But in the models below that, they did switch to coreless motor. One example is the PL-50L, core motor, and the latter PL-50L II, coreless motor.

Looking at it historically, the trend in DD design is that by 1975 just about every table is quartz locked ( the "QL" in JVC models) and 1977 point on to early 80's, many Japanese manufacturers switched to coreless and stayed that way until CD took over the world.

One physical feature of a typical coreless motor is that they shape like a pancake usually flatter than their core siblings. It's because a coreless motor has no iron core to wrap around and they shape like a series of air coils in speaker crossover and the rotor is right on top of the coils.

I cannot scientifically confirm coreless motor is responsible for the fluidly smooth sound compare to other motor genres but from my own experience every DD table I heard using coreless motor has that sonic character. The first time I heard this smoothness was from a cheap Pioneer PL-300. It was outperforming its earlier more expensive siblings that got me curious about its motor structure. Playing records of violin solo gives a good idea of its smooth character.

03-26-14: Banquo363:
"There appears to be some disagreement regarding whether the tt 81 has a coreless motor or not. The vintage knob asserts that it does, but 'caligari' on this thread says he's positive that it does not."

Nowhere in the text of VintageKnobs.com mentions that the TT81 is a coreless motor. It says "the motor of both versions is a high torque 12-pole 24-slot DC-brushless." A brushless motor is NOT the same as a coreless motor.

After some research, the motors of TT71 and TT81 might be similar but they have different model numbers. TT71 uses M932A motor and TT81 uses M922A motor, according to their service manuals. The TT101 uses a M926 motor, by the way.

_______

When I used the word "stubbornly," I did not mean to discredit Denon and Technics in their confidence of the maturity of their designs and technology. If they felt their chosen motor type resulted in good sound quality then there's nothing wrong with not following the trend. It was just an observation and not a criticism. Personally, I felt Denon DD tables produce great sound. And I'm sure Technics followers would say the same. As the saying goes, many ways to skin a cat, right?

_______
hiho:

go to the 'specs' section of the page for the tt 81, here. For motor, it asserts: "FG detecting Coreless DC Servo"

That specs page is for TT-71, which the writer is assuming its motor is similar to the TT-81 and I can say the assertion that it uses a "coreless motor" is absolutely wrong because I owned several TT-71 units before and I have looked into the guts of all of them, all core motors. I even looked into the specs pages of TT-81 and QL-A7 (uses TT-71 motor) from their service manuals and none mentioned "coreless" motor.

Here's a simple proof. Just look at the first picture of the Amp8 repair page on a TT-71 under surgery and you can see the coils wrapped around the iron core. Axel, the owner and webmaster for vintageknobs.com might be an expert on Sony products but he's wrong on this JVC model.

While the TT-71 is quite decent sounding, better than most Technics, it is not quite up to the level of JVC's other DD tables with coreless motor. The TT-81 might be a different story though and based on Halcro's testimonial he seems to like it quite a bit.

_______
The specs are for both the tt 81 and tt 71, the latter's specs being in brackets. So, he doesn't say anything about the tt 71's motor, since that is blank.

The only way to settle this is for Halcro to take his tt81 apart ;).
hiho,

The english flyer for the jvc ql8 has a small black and white pic of the tt81 motor. Take a look and see if you can tell whether it's a coreless motor or not.

More observations I made earlier in the other thread.

Here's the major clue from the vintageknobs page.

Halcro did post some innards pictures of his TT81 but short of the inside of the motor. That TT81 looks awfully close to the TT71 motor.

Yes, Halcro needs to take apart his TT81 to settle the score! :-D

_______
Wonderful information, photos and Links from HiHo as usual.........
I really think from the descriptions of the TT-81 and TT-101 motors in their respective Service Manuals....that HiHo and Caligari are correct about the TT-81 NOT being a 'coreless' motor?
As for me taking apart my TT-81.......HaHa HiHo.....and you too Banquo....:-)

But for your collection of images HiHo......here are all the ones I have of my TT-81:-
TT-81
TT-81
TT-81
TT-81

If the TT-71 and TT-81 motors are the same......why have the two models?
The TT-71 motor is described as "12-pole, 24-slot, DC type FG servomotor with Starting Torque of more than 1Kg-Cm and Drift per hour of 0.0001%"....whilst the TT-81 motor is described as "DC Servomotor with Starting Torque of 1.3Kg-Cm and Drift per hour of 0.0004%".
These are different specifications with the added benefit of the TT-81 having quartz-locked positive and negative servo control as does the TT-101.
Perhaps the most defining clue to the differing motors is in their Power consumption...13 watts for the TT-81 and 15 watts for the TT-71.
Regards. Hiho is correct. For a description of JVC technology in the above TTs:

http://www.vinylengine.com/library/jvc/turntable-technology.shtml

A later catalogue states ALL TTs are equipped with coreless motors.

Peace,
HiHo,
Your interest in the Victor motors seem to have been ignited by your experiences with the TT-71.....is that correct?
Your research, photos and Links are certainly invaluable to this Data Base.
I haven't heard a TT-71...but I know the Professor (Timeltel) has one and is quite pleased......
I have more than five times the expense invested in my TT-101 over the TT-81....and would love to say that the performance difference is worth the cost....?
Unfortunately (or fortunately)...that is not the case and I can honestly say that I can hear no differences between them.
But is that really so strange?
Apart from the added complexity of the electronics and the coreless motor.....the rest of the architecture of the two TTs are identical.
Same platter....same materials...same dimensions and structure and same quality of electronic parts.
As you can see from the Timeline videos of the two TTs.....their speed accuracies and consistencies are identical....so why wouldn't they sound the same?

As they are the best sounding turntables I have heard in 40 years.....the TT-81 must be the bargain of the century? :-)
Hearing back from Antonis about his TT-81 plinth......I was wrong about the granite slabs I thought he used.......
Instead of granite slabs.....he has designed and constructed some exotic stressed skin panels utilising bauxite balls and epoxy sandwiched between two sheets of aluminium.
You can see it all here
Who needs (new) turntable manufacturers when we have inventive and knowledgeable audiophiles able to utilise the best DD turntables ever made?
Hello Halcro,

I own 2 of the TT-81's. One is in storage sitting on the shelf. It has been completely rebuilt (including all caps.)
Your comment about it "must be the bargain of the century" is something I have to agree with. I also own a VPI Aries Extended with all mods. I prefer the TT-81!
Regards'
Don
04-04-14: Halcro:
"If the TT-71 and TT-81 motors are the same......why have the two models?"
While I cannot confirm they are the same -- the motors have different model numbers but, I believe, have similar structure -- there's really nothing unusual about using the same motor in different models. JVC and others are giant corporations and they don't think like audiophiles. It was very common to use similar parts with different features. Sometimes with improved electronics they implemented into older models with added features to come up with a new model. That happens all the time in their integrated tables and I can think of at least 5 or 6 models share the same motor. The JVC QL-Y66F has the same motor and electronics as QL-A70, except one has automatic tonearm and the other with manual tonearm. Just look at Technics, the SL-1200Mk2 architecture had been used in 6 or 7 models with various features such as tonearm, plinth, suspension, automation, pitch control, etc....

The best view of the motor is actually from the top, remove the platter and motor cover and you can get a glimpse of the motor structure. Judging by the provided photos, the motor is canister type so it's very likely a variation of the TT71 motor which is a core motor. Please continue to provide us motor porn though. :-)

At the end of the day, what matters is that you like the sound of the TT81 regardless of motor type. But the TT71, while decent, makes me desire more so I moved on to their integrated tables, which are sleepers but usually audiophiles are annoyed by their automatic tonearms. If many of these quality integrated tables have an armless version, history would have been rewritten. (If Lenco had more armless L75 models, audiophiles would not ignore them for so long. I know they do have the G-88 but...) The TT81 has advanced electronics so that might have pushed the performance to another level, evidenced by your approval.

My own observation so far is that I tend to prefer tables with coreless motor, they pass the solo violin test, exceptions are ones with magnet-less motors as found in Denon induction motor a la DP-60 or Sony PS-8750 or older Sony drag-cup motors with a copper rotor. Aside from top of the line models, many DD tables with traditional core motors as found in models by Technics, Pioneer, Kenwood, etc... do not float my boat. Of course, the motor is just one part of the turntable but in a DD system it's a major contributor to the sound. One can easily argue that the weaker torque of a coreless motor has a less dynamic sound and less drive or "jump" factor in character. So at the end of the day, find what you like is what matters. Audio is like food for me, I'm all about flavors and colors. Lamb chop is great but on some days I just want a salad. That's why we have multiple turntables! I'm sure someone (Raul?) will jump at me about neutrality, faithful to the source, bla bla blah...

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Regards, Hiho: A TT71? Guilty. Picked up for little more than pocket change several years ago just to fiddle around with. A hard maple plinth & EPA-250 tonearm. Swapped around some mats (the OEM mat is terrible) & ended up with a Boston Audio Mat2. The basket shrouding the electronics rings, so strapped a couple of bungee cords around it. Cyro'd bungees are in short supply, used what was available. Bluejeans brand entry-level low capacitance cables & some Isonoe feet at the corners. Pulled the Pio. Exclusive PL-70L 11 & then sat for a semi-serious listen.

The little 71 lacks the ability to capture micro detail but is engaging and involving, I like your reference to flavors and colors :). You mentioned Raul; the gentleman also sampled the TT71 and actually praised it, I believe he used it "nude".

No Timeline available but out of curiosity the 71 was timed for eighteen minutes. From a cold start it immediately advanced a nominal four degrees and then remained spot on for the remainder. It's been a while since researching but IIRC the 71 lacks the reverse eddy current braking both the 81 and 101 implement in regulating overshoot incurred when correcting for speed. Other than the coreless motor, the only other difference for the 81/101 is the readout for the 101 is digital, the 81 is equipped with a strobe.

Just an enthusiast, I find critical listening a distraction. I've not read a negative comment concerning either the TT81 or 101, JVC seems to have gotten the series right. Of this I am certain, in spite of, or perhaps because of, the resonant character of the modest 71 it is somehow a captivating performer. Some day I'll return to the PL-70L 11 with it's "stable hanging rotor" drive and exquisitely engineered PA-70 tonearm and then experience a revelation as to what I've been missing.

In reference to Halcro's OP, among others I've a Tech. SP-15 which I expect to someday start spinning like a gyroscope and a Denon DP-60L (a carnival of resonances) with it's fragile magnetic tape attached to the platter.

Pardon the lack of references, corrections to any of the above are welcome.

Peace,
04-04-14: Banquo363:
"The english flyer for the jvc ql8 has a small black and white pic of the tt81 motor. Take a look and see if you can tell whether it's a coreless motor or not."
Good find!

TT-81 motor - & - TT-71 motor

Yep, just as I suspected. The TT-81 motor is indeed a core motor, same structure as the TT-71 motor. Notice the coils wrapping around an iron core? You just save Halcro the hassle of taking apart his TT-81. :)

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Timeltel, I like your tinkerer's spirit. :)

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