In Reply to: building 10's with a friend posted by Randy Bey on April 07, 2001 at 09:39:34:
Don't settle for getting electrolytic or tantalum capacitors at your local Radio Shack. I can understand the misconception that a cap is a cap is a cap, but please do understand that this is not right. Each technology measures very differently than the others. They're all different, each having their specific strengths and weaknesses. It isn't a pseudo-science audiophallic thing like some cable debates, this is an easily measured, quantifiable linearity issue.I don't necesarily recommend expensive audiophile parts. But I do strongly suggest these criteria be met:
1. Caps under 1uF should be polypropylene film, metal foil caps. They don't cost much, so there's no point in getting a less optimal part.
2. Caps over 1uf can be metalized polypropylene film instead. It's hard to find large film/foil caps, and one would pretty much have to use an expensive brand to get a film/foil much larger than 1uF. I'd prefer film/foil, but not for 30 bucks as opposed to a buck and a half.
3. If you need a huge cap, build it with parallel values of a smaller one. Don't go electrolytic.
4. Coils should be air core, unless large enough that resistance grows above 1/2 ohm or so.
5. Resistors should always be non-inductive and not wirewound. Wirewound resistors (obviously) have an inductive component. I mean to say that they are partially inductive devices, rather than being purely resistive.
Jerrod's suggestion of www.PartsExpress.com is a good one. All of the items I've just mentioned can be found there.
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