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
@lewn

Such a subtle problem may indicate some cold welding, but it is too long to rework all the welds.
Finished this big thread and made my notes regarding different TT-101s samples, owned by several people here. Maybe i was too optimictic when i ordered mine, but after reading all comments i’m not so happy about it. The unit if from one owner and rarely used, perfect condition, but must be fixed.

The situation described below by Lew is exactly what’s going on with my Victor TT-101 right now:

@lewm
There is no problem in terms of displaying 33.33 or 45.00. It goes right up to display those two speeds and holds those numbers firmly. The problem is that occasionally it will go into its typical failure mode after 3-4 minutes: the tach lights go out, except for the decimal point, and the platter coasts to a stop (no brake effect). It’s as if someone pulled the plug, except the power lights are all "on". If you then re-start, it will work fine, as if nothing bad had happened... The problem with my TT101 seems at the moment only to have been a tiny crack in the main PCB, right near the edge. JP thinks it occurred during manufacture, 30-odd years ago. The circuit was only maintained by solder, and once the solder cracked (invisibly, I might add), the result was a fault in TT101 function that was manifested intermittently, depending upon stress on that PCB. There was no need to replace the SC3042 chip in mine or indeed any of the discrete transistors. Great work by JP to find this problem, only made possible by the fact that the thing finally malfunctioned in the presence of a smart guy who knew how to trace down the cause. Other such problems are being searched for, just as a precaution before I get it back. I hope this is not premature, but I am very pleased.

It’s my first day to plug it and turn in on, no promlem with speed stability at all, despite the fact that it takes 2 second before the digits on display turning from 0.00 to 33.33 or 45.00 Pitch works fine, stop button works fine, power button works fine too. But i can only run it for 15 minutes, sometimes only for 1 minutу (as described by Lewm above). Actually right now it's still spinnin' for 30 min. Maybe burn-in process is important and it will run longer. Sadly i’m not in USA to send it @jpjones3318 and his time is limited now. Lew has mentioned Tuchan’s tech in Germany which is much closer.

@banquo363
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. 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 http://modularsynthesis.com/ .

Second "man of audio dreams" is also in USA, too far.

@halcro and @downunder
Glad Chris (Kimil) helped you Downunder. His ingenuity, understanding and competence in all things audio are unequalled in my experience... I took back my TT-101 to have him adjust the variable resistors for the platter brake system. As I discovered....Victor added this feature to allow for the differing weights of various mats...and as I changed to only a thin Victor pigskin mat directly placed on the aluminium platter.....the brake system didn’t perform as required. It took Chris precisely 20 minutes to adjust them ( one for 33.3rpm and one for 45rpm). No charge...and they work perfectly.. I would waste no time in having him replace all the electrolytics in your P3. Since my TT-101 had its done....the speeds are consistently perfect.

I assume Chris Kemil is Australian, well, keeping in mind the shipping price for my CU-180 for Downunder i assume it will be extremely expensive to ship the TT-101 to Oz.

SO WHAT CAN I DO? Is that require some sort fo special knowlegde or experience to fix it locally with some tech?


Hi Misha

Come to Sydney for a holiday and bring your turntable.

Yes, Chris is in Sydney.

Cheers
Regensburg in Bavaria may be closer to you chakster......
That's where Thuchan's Tech resides and I've witnessed his work first-hand.
It's first class and he now knows the TT-101 inside out....
Hi Misha,

The two seconds for the display to change is normal.  If you put it in run mode you can watch it count up.  It does the same in hold mode, though only updates the display at the end of the cycle - every 1.8s IIRC.  

If it's stopping as Lew described you've a situation where too much current is being supplied to the motor.  Time won't fix this; it's likely there's a bad connection on the board.