Microphonic capacitors?

[nee]

Is it usual for coupling caps to be microphonic?

The .01uf coupling caps on my amp are microphonic when I tap on them with the old chopstick. I replaced them with Sozos - same thing.

[Jana]

Orange drops are certainly that way. Mallory or Sozo are usually a lot less.

Are they in tune when you tap them?

[nee]

Are they in tune when you tap them?

Certainly if I'm playing Page, Green or my own stuff. Less so if it's Angus Young. Definitely out of tune if it's Metallica.

[rfgordon]

Another term for a capacitor is "condensor." A signal cap in an amp carries AC signal, but has a DC voltage on one side. That's essentially what a condensor mic is. The signal is AC and the 48 VDC phantom power is the DC voltage.

In other words, no, it's not unusual for caps to be microphonic.

[Andy Le Blanc]

I've had a few issues with noisey caps..... the leads can become loose if your
not carefull....or reuse parts..... but generally if they dont pass a thump test
they should be swaped out..... many things can make noise.... cheap wire
can have a capacitance that can be microphonic..... its the application that
counts.... if they dont hinder the performance of the amp .... keep em....

[bnwitt]

Yes indeed. As was stated above, you can overheat them or mishandle them and they can become micro phonic. Also a bad solder joint on a lead can cause it. They can come from the manufacturer that way as well. I differ on the occurrence by brands stated above, however, as I've had more SoZos be micro phonic over any other brand.

[Jana]

I probably spoke too soon about the capacitors, I just pulled a microphonic Sozo.