Silver Mica caps VS Polystyrene caps

[KevinLee]

Hello,

I just replaced a few ceramic feedback caps in my integrated amp with silver mica caps.

The difference was not small.

I used to play this greatest hits album by Lenny Kravitz and its sound was very fatiguing on my system. The sound is now very articulate and the album is easy to listen to .

For me this is good.
Cheers
KevinLee

[mcp]

Hi Kevin

Glad to hear you like it.

You may want to have a look at the input. There should be a cap of small value to ground (ranging from 100p to 470p, sometimes even to 1n). If it is a ceramic, replaced it with a silver mica or polystyrene.

Originally posted by SY
Never lost one, whereas I've replaced bunches of polystyrenes

I had polystyrenes failed on me before. That could be due to using it at the limits of WDC.

If there was any sonic difference, it escaped me.

It could be on the speaker side. Often speakers are calibrated at 1m/1w for flat response. So, most tweeters are padded down resistively. I find padding doesn't just attenuates, but dulls the music. Like losing harmonics.

My approach is not to pad the tweeter and build the speaker from there. I find it so much more "lively". The only component I pad is super tweeters, and ever so slightly. As for 1w/1m flat response, I abandoned that long time ago. It should be restricted to near field monitors in recording studios only.

[SimontY]

Hi,

Is it easy to locate feedback caps in an amp - would one need a service manual? Are they typically ceramic types?

mcp,
We seem to have strayed slightly off-topic here, but what resistors do you reccommend to minimise quality loss from a tweeter? (I only need 1ohm in my current ones)

Cheers,
-Simon

[SimontY]

Oops, kinda forgot my main point!

I replaced two mylar caps in my cd player output with silvered mica, actually it was a slightly different value to 'tailor' the treble roll-off. The sound was only slightly changed, it got more relaxed, but that could be more treble roll-off than cap type...

After reading this thread I think I will replace the rest with silvered mica. I was going to use polystyrene as I thought these might be better, but as I've started with mica ones, I may aswell finish with them...


-Simon

[mcp]

NFB Caps: If you are not familiar with amplifier designs, I'm afraid it can be quite hard to tell.

Ceramic nfb caps: Normally in lower cost amplifiers.

Tweeter Resistors: Normal 5W ceramic if I need to pad and less than 1 ohm.