Capacitor/amp question

[BrianG]

I would replace with the same capacitance and voltage. You can use one rated for higher voltage, but it will be bigger. Caps have a few purposes: oscillators, filtering, and (de)coupling. If it's just a filter cap, bigger is usually better. But, if it's tuned to a certain frequency, or used for (de)coupling, you should stick to the same value. They probably are not low-ESR, so you should be able to find a direct replacement at RadioShack.

Usually, a bad cap has a puffed or rounded top. So look for that kind of problem first. But, just because they aren't puffed doesn't mean they aren't bad (the electrolyte could have leaked or something).

To eliminate the pop coming from the turn on lead, make a temporary jumper from your battery lead (on the amp) to simulate the control signal (remove the existing turn-on lead first). If the pop goes away, you can use a relay to create a new turn-on lead.