I believe GE makes these still. Check through the Allied, Newark,
Electro-Sonic, etc. catalogues and you are sure to find what you want
eventually.

rod keys wrote:

Gents,

The last time I built speaker cross-overs was MANY moons ago. I used
"oil filled" caps about 20 mfd that were meant for timing circuits in
old vacuum tube instruments. (I know, 20 mfd = rather low crossover
frequency). But I'm not able to find such caps any more!

The problem is three fold. 1) Rather high mfd value, 2) Need to be
non-polarized, 3) Need to sound "clean" (no extra internal
resustance, inductance or "chunkie" electrolytic action). The old
trick of electrolytics wired "back to back" works - kinda - but they
sound like electrolytics ... (read, how to make a perfectly good tube
amp sound like a solid state amp).

What's available for good cross-over caps today? Are motor starter caps
true oil fills or some cock-eyed variation on electrolytics?

And what's with PCB content in old oil caps? I must admit that I find
PCB paranoia more hype than science, but it seems like it's driven many
good components out of the market. Is this why real oil fills have
disappeared?

Rod