Vintage DD turntables. Are we living dangerously?

Yes you are!!

This is an interesting thread in that I had planned to send Halcro a PM asking who he was sending his DDs to for repair.

I once did a global search for 2SK147 (a low noise FET). At the time they were, as Lewm said, available if you searched for them. The hitch was that you had to buy industrial quanties, minimum of 100 pieces (IIRC), at whatever price being asked. In fact, there are companies who specialize in finding and stockpiling obsolete chips.

That said, I have seen techs with amazing knowledge, skill and training, struggle for months trying to fix audio esoterica from the Japan Inc heyday. So, just because we are not electronics experts, that doesnt mean repairs on such gear is necessarily simple or easy for the expert.

One thing we might do is get together and identify a tech that has the skill to fix and keep these pieces running - and then give him our buisness. Sure the original chips might die but their final function is generic. Perhaps a such a clever tech can often design a circuit to replace the dead chip from the signal and PS input to that chip to where the dead chip rejoins the circuit.
Mike

Dear Halcro, There is nothing as cruel as the thruth.No wonder only a small part of the human kind pretend to be interested in the real truth: the scientist. I want mention the assumptions about the spead of light and their reaction about possible refutation of Einstein. Refusing to except anything else is some evidence of the mentioned 'pretending'. Why do you want to scare us? From the other thread in which you are also involved it follows that there are no good TT's whatever. I was not able to comprehend the arguments but well to understand the conclusion. My only consolation is the fact that I never bought those astronomic expensive plinths nor the similary expensive TT.

Dear Lew, There is one Victor TT 101 on the German ebay for
1000 Euro and if you like to prove that you are right you
are welcome to try. Halcro warned me just in time to avoid
my temptation.

Regards,

I have to agree with Lewm on this one. I made my living for decades servicing all sorts of audio gear. I would regard it as highly unusual to see a chip failure!!

That is worth repeating: I would regard it as **highly unusual** to see a chip failure!!

Usually you see dirty switches and controls that result in poor speed regulation, electrolytic caps failing- that sort of thing.

So I would see an explanation like this as a bid for a lower price on a prospect.

Now, if you live in a tropical environment, the chips are in a little more danger, from corrosion. If you want some simple protection, you can 'pot' the chips with silicon sealer, the clear kind similar to aquarium sealer. I should point out though that in tropical environments the circuit boards in general are in great danger, so usually you have other concerns that far outweigh the chips... In non-tropical environments this is probably not an issue.

These days I do far less servicing than I used to, but I still maintain my own vintage analog synthesizers that I play in my band. They use a lot of unobtainium chips too! I would say the major force that causes the price of such ICs to rise on eBay is mis-diagnosis of other problems in the synth (usually bad connectors and electrolytics)! I see it all the time....

Dear �Nandric, Go ahead and buy that TT101, if you want it. Here is a URL for the owners manual AND the service manual, which can be downloaded from Vinyl Engine:

http://www.vinylengine.com/library/jvc/tt-101.shtml

Armed with the service manual, any really good technician worthy of the name can repair the TT101, save for the "unobtainium" chips, that might not be so unobtainable. To add to Ralph's cautionary comments, I would say that the first thing to do after acquiring a vintage dd with unknown service history is to have all the electrolytic capacitors replaced. After 20-30 years, it is quite likely that at least some of the caps are leaky or otherwise defective. Leaky caps can lead to destruction of one of those precious ICs. Also note (Mgreene) that no vendor asked me to purchase the Denon chip in bulk. I had the choice to buy only one or as many as I wanted.

In the US, Bill Thalmann of Music Technologies in Springfield, VA, can repair any of these tables, is extremely smart and honest, and is an audio hobbyist as much as we all are. Music Technologies has a website.