I guess the title says it all.
I know when recapping amps, it's important to replace ceramics with ceramics, polys with polys, etc, because the sound different. Is that also true with the tone control on a passive bass, and with the treble bypass on a volume pot? All basses I've looked at seem to have polypropelene caps, which are twice as expensive as ceramics (a whopping 49 cents or so ;) ) Is there a reason for this?

Originally posted by Skips
I guess the title says it all.
I know when recapping amps, it's important to replace ceramics with ceramics, polys with polys, etc, because the sound different. Is that also true with the tone control on a passive bass, and with the treble bypass on a volume pot? All basses I've looked at seem to have polypropelene caps, which are twice as expensive as ceramics (a whopping 49 cents or so ;) ) Is there a reason for this?

I've never heard any knowledgeable person claim convincingly that the type of cap used made any difference at all to the sound of passive bass. I've heard a bit of hearsay, or myth-mongering, but nothing that made any sense to me.

The one reason I've heard for using polypropylene caps over ceramic in a bass that seemed plausible to me is that *supposedly* manufacturing tolerances are tighter with poly, so that if you're buying a .022 mfd cap, you have a better chance of getting a value close to .022 with poly than with ceramic.

FWIW, Chris Kinman (the Aussie guitar PU maker) claims something similar with respect to pots: he says that cheap pots can often vary wildly from their rated value (e.g., 117 kohms for what's supposed to be a 250 kohm pot).

Thanks--didn't know that.
I've tested one or two cheap pots, and always found them to be very close to their rated values (249 or so for 250--maybe I was just lucky). However, Cheap pots get scratchy and go bad so much that I'll stay away from them anyway. :)

You kinda got me thinking about this, so I poked around a little. Found this, FWIW:

http://mywebpages.comcast.net/skgs/sk/CapTest/CapTest.htm

The author is a guy who makes and rewinds pickups.

none of those graphs load for me.:(

Originally posted by Skips
none of those graphs load for me.:(

Nor for me. Drag. But anyway, what he thinks is pretty clear from the written summary.

yeah, and the other site with the scopes also says a lot.
Thanks a lot :)