phil symonds

Bernard,
You didn't describe the noise for us. Hum, hiss, buzz, something else? It
would help to know. BTW, nice clean looking board you've got and plenty of
room to work. I think the big polar caps are in the "dog house" underside
of the chassis.

You may need to fix the various noises in a series of steps. Given the age,
like Phil A says, I'd do the big filter caps first. Buy good quality.
Folks here seem to agree that Sprague Atom caps are the ones to go with. I
see you post from Germany, so if you are actually there, I don't know what
you can get inside your country easily or mail order without paying the
import duty. (I post from a server in Germany because it's free, but I'm in
the US.) Buy the right values for replacement. Buy fresh caps or (second
choice) NOS that have been properly tested and guaranteed. Old caps are not
a good choice. After you change the caps, you can see what noises are still
left to deal with.

If you've got the time it would be worthwhile to test each resistor to see
if it matches the spec +/-10%. Remember, this is done out of circuit,
meaning you will need to desolder one lead and lift it from the board before
you put the mutimeter on it. Replace the ones that have drifted. For those
in the *tone* circuit you probably want to get carbon comp resistors for an
exact replacement. They are being made, but are not so easy to find
everywhere. They can be mail ordered from a few places in the US.

If you've got hiss after the cap job, you probably need screen resistors.
It is my understanding that no "tone" runs through these, so modern metal
film resistors of the same value are the routine fix. Some purists
disagree, but they work fine for me.

Lots of luck,
Phil Symonds
Rank Amateur Amp Fixer
It pays to do your homework first