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Alps Blue Velvet pots

post #1 of 9
2/27/11 at 11:54am
Thread Starter 

I recently disassembled an old beat up tape deck i had had lying around for some time, collecting dust. I grabbed the two pots, as it was a decent tape deck, and I assumed they would be decent pots. I looked up the part number on the back of them, with nothing found, so I looked up one of the other numbers on them. It was 10K(Ohm)AX2. Found out that the AX2 stuff is usually associated with the Alps blue velvet pot. My problem, is that, this one is totally different than the ones I have seen, with a completely different part number. It is quite old, and not board mount, but with fins for attaching wires. It has QVD2A3A-014V as well as 72N on it. Is anybody familiar with this pot? I have a second 50K one as well, which has independent knobs for each of the stacked potentiometers. Are these indeed the nice Alps Blue Velvet pots?

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post #2 of 9
2/27/11 at 2:13pm

AX2 just means Audio taper ×2 channels; that is, it's a stereo volume control.

 

ALPS makes a wide variety of pots, from junk to great.

 

ALPS does not make any pot called a "Blue Velvet". That's a marketing term originating with a once-popular source of these pots. I occasionally use it on my site only because some people may be familiar with that name and not is proper name, the RK27112A. The reluctance of some to use its proper name is understandable. smile.gif

 

Most ALPS pots in the golden zinc-plated enclosures are hard to differentiate. If that's the sort you have, there's probably no point posting pics. The best ways to tell if your pot is good are:

 

  1. Put it in something and listen to it in comparison with something whose performance you already know
  2. Measure it.
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post #3 of 9
2/27/11 at 2:22pm
Thread Starter 

I have nothing else to compare it to, really, just starting to get into this type of stuff. I also don't really care for that type of test. I do have an oscilloscope and a function generator though, so I will do some similar testing to the tests on the linked page. The one I have is the zinc-plated enclosure, and it looks like its just two potentiometers stacked. They do sound like they have good channel matching, but, i will have to try and see.

 

Thanks for the information though. Think there would be anything else worth grabbing out of the tape deck? I know it has mylar caps and such, but it also has some Dolby IC's and such. No op-amps or anything like that in there probably?

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post #4 of 9
3/1/11 at 4:58am

Vu-meters maybe ?

Cable pass-through ?

Power switch ?

Knobs ?

Fuse holders ?

The enclosure itself ?

 

The rest is probably not worth grabbing.

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post #5 of 9
3/1/11 at 6:43am
Thread Starter 

I got the VU meters, and all of the front panel stuff (although not necessarily the electronics, just the mechanical. I love the brushed aluminum look, and plan on using all of the brushed aluminum parts in the CMoy build I am working on. I will grab the capacitors and resistors, as, I hate to buy those things. They are so damn small, and so plentiful in old electronics, it seems a waste not to use them.

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post #6 of 9
3/1/11 at 10:48am

Beware of old carbon resistors. They tend to drift (sometimes drastically) in value with time.

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post #7 of 9
3/1/11 at 3:45pm

Leave the electrolytic caps behind, too. They have the shortest useful life of any solid-state electronic component. Of those that are still functioning caps, all are probably out-of-spec now.

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post #8 of 9
3/1/11 at 5:10pm
Thread Starter 

tangent, just noticed you were from Aztec! Good to see some other people from NM on here.

 

The caps in this deck are almost entirely mylar, so they should be good, right? I know most designs recommend mylar and similar.

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post #9 of 9
3/2/11 at 11:30am

Yeah, there are a handful of us Nuevos Mexicanos.

 

By all means, scav the polyesters.  They're not perfect caps, but they're all but bulletproof, and far better than ceramics in most regards.

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