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
Doron:

Platter height is adjustable via a screw at the bottom of the unit (where the bearing is). You'll have to take off the metal cover to access it. It is cemented into place per stock, but perhaps the previous owner messed with it. Scraping is likely due to the platter being too low. Mine was the same way. Perhaps the bearing oil ran out or up due to shipping, thus causing the platter to sink ever so slightly? You might wait a day or so to see if it self corrects before messing with the bearing screw.

As Totem said, don't run motor w/o platter. It's calibrated for a specific load, so it shouldn't lock speed w/o platter. I'm surprised to hear that it locked at 45 for you.
Fleib, On 8/29 or thereabouts you wrote, "Lew,
You mean 21mm short of the lead-out groove, which would be about 80mm from the spindle?" Then Hi-ho made some further comments to indicate that 76mm is correct.

But if you guys will look at the diagram in the article quoted by Hiho, follow the arc formed by the dotted line. In order to achieve zero tracking error (stylus tangent to groove) at point B, as defined by the designer of the RS-A1 in that diagram, the stylus needs to hit the label or the run-out grooves of the LP where that arc comes closest to the spindle, which I think is indeed about 21mm from the spindle. Thus we were talking about two different things, in one case how to mount the arm, in the other case, where on the LP playing surface we wish to achieve the one point of zero tracking error.

As to the Rigid Float. All that babble about how the "bearing" is constructed does not allow me to form a picture in my mind of how it works, how something can be both "rigid" and "floating". I would need to play with one to convince myself. Well Tempered liked to sell the idea that their tonearms have no bearing and hence no bearing friction; the problem is that their bearing (which IS a bearing, semantics notwithstanding) has a fair amount of play and so low friction is achieved at the expense of wobble.
Doron, I agree with the others, it's probably best not to run the motor without the platter installed. It's definitely taboo for nearly all other DD turntables, for sure. However, I faintly remember that Bill Thalmann told me that where the TT101 is concerned, you can get away with it, because of how the circuit works. Even with that small qualifier, why worry about platter-less operation, if your TT101 works fine with the platter installed? If you follow Banquo's advice on how to raise up your platter by a few mm, via adjusting that screw below the bearing housing, you should be able to cure the scraping problem as well. Now, replace all electrolytic capacitors.
Hello and thank you all!!!
Much appreciate your help!
1. Re the platter/spindle height adjustment screw, do you need to remove the black upper motor cover to access this screw?
2. Any chance you could send a photo showing it? (doronor3 at gmail)
3. In addition without the platter installed, is there an allowable, slight (~1/16") axial movement of the spindle/shaft?
In other words, if I pull the spindle upwards by hand, it rises about 1/16" from its normal rest position.
Is this normal or is it an indication of excessive axial float?

Thank you kindly!

Doron
Ok, found it!!! (The spindle height adjustment screw).
Removed the bottom black cage and it it's a brass large flat screw at the bottom.
Once I screwed it in slightly, the shaft went forward and the clearance/axial float of the spindle/shaft was reduced a bit. It still exists but just smaller. Is this normal?

The platter now rotates freely now (no scraping) and the motor locks on both speeds readily.

Thank you so much!!!

Doron