"Bryan McGivney" wrote in message ...
I got a Hoffman Stereo Hi-Fi console at the Goodwill because it had a tube
amp in it and I wanted to pirate the amp for a fun project. Well I pulled it
out of the console and fired it up and it hummed badly. It has two multi
part can style caps on the chassis. I found caps at the local supply house
and wired them in below the chassis to the terminals on the original caps.
The amp sounds fine now but I figured I'd ask if there are any issues with
not having removed the original caps from the circuit? I hooked the caps up
with what I think is about 18ga speaker wire, with the copper conductor on
one side and silver conductor on the other. This shouldn't cause any issues
should it?

How hot might one expect the power transformer to get? I can touch it but
it's hot enough you don't want to hold you finger on it long. My guess is
around 110 - 120 degrees.

I have seen reference to adding a modern power socket like a computer would
use and using the 3 prong grounded cord, grounding the chassis to help
reduce hum or noise. Is this usually OK or might I somehow get myself into
trouble doing this?

I want to make a wooden enclosure for this with a metal screen top or
something like that. It seems that 17" is about the width of most
components?

Reading the comments along with new tubes it looks like JJ/tesla might be
the winner of not being the cheapest or the most expensive, just inexpensive
yet good sound. I would need 2 x 12AX7 and 2 x 6BQ5. Should these work well
or might I consider others?

The amp has a switch for off, stereo 1, stereo 2, mono 1, and mono 2. There
are only one set of speaker outputs. Is this maybe a setting for 4 ohm and 8
ohm? I think the volume goes up a bit in the 1 positions.

Are there voltages I should be checking or stuff like that?

There is a little pot on the back marked HUM what should I do with this
adjustment?

Well it's late and I am sure there may be more questions but that's all I
can think of for now. More than enough for one post anyways.

TIA,
Bryan



I would remove the original caps,and maybe mount the new ones in
thier place,under the chassis is fine also.The old caps may be leaky
(electricaly) and drawing excess current from the power tranny.(making
it run warmer.) Make sure your new caps are close to the same
values,and rated for the voltage,or higher.
You might want to use wire rated at 600V..speaker wire might not cut
it at B+ voltages.
Those JJ tubes should work fine for ya. I think i have a pair in some
SE 6BQ5 amps myself. ;-)
The HUM control is just that.:-) Adjust it for the least amount of
hum. (I believe you'll want to unplug the input first.)

Good luck!