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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
lewm
12,448 posts
 
Look near the AC cord outlet to find the recommended AC voltage.
pablogab2k
8 posts
 
Yes, 120v 60hz 23W.

I used contact cleaner on each pot, moved them back and forth and set them back to where they were.
it did not take care of the problem.
the motor seems to speed up to top speed and then come down to almost a stop.
the digital display does not change because it seems that it’s taking an average.

jpjones3318's avatar
jpjones3318
148 posts
 
There's simply no way the calibration survived that.  Barely nudging those pots drastically affects the circuit, and in the drive circuit they all interact.  The mechanically tolerance affects the setting, so aligning witness marks won't work.  Best rule of thumb on quartz/PLL DD circuits: don't touch the pots unless you can recalibrate yourself, or have it done. 

lewm
12,448 posts
 
 Under the platter, you will find a rocker switch labeled “run” or “hold”. In the run mode the tachometer will display the RPM from zero to the set value. For example if you are set to 33.33, then the tachometer will read from 0 to 33.33 over and over again. This can be very distracting.  Maybe that’s what you are looking at. Check that switch under the platter. Set it to hold and you will see a static display of the RPM. At least you should see that. If you see anything else, that is an indicator of a problem. Also, I would point out, with all due respect, that cleaning the contacts is not tantamount to changing all the electrolytic capacitors. Without meaning to sound dour, the more you power up the unit without having identified the problem, the greater is the possibility that one of the hard to find ICs is suffering a fatal calamity. 
uberwaltz's avatar
uberwaltz
13,381 posts
 
Question for all you vintage DD experts out there.
I have just acquired a Technics sl10 linear tracker which looks to be fully functional and in good shape.

My question is concerning the RCA out.
It looks like it has a built in phono amp as the little button next to the RCA outs says mm/mc.
Does this mean it cannot be used through a phono amp as there does not appear to be a bypass to this , just choice of mm or mc.
Thank you
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