u235vu239 wrote:

I bought this pioneer amplifier (SA-408, similar to the SA-410, I
guess), but it has two big problems:

1. when I turn up or down the volume, it makes this really nasty noise

Dirty potentiometer. Often you can get the dirt out by just turning it
back and forth over it's working range ten or twenty times. If that
doesn't work use a contact cleaner, or replace the pot.


2. it seems that it can't reproduce the left channel, as the whole "RCA
lefts" seem to be dead (only the "RCA rights" can reproduce any sound)

A dirty switch can cause this, especially the tape monitor button. Or
you might have something actually broken in the signal path. Hard to
tell from here.

//Walt