CHAMP ELECTRONICS -" THE VINTAGE VALVE AMP HOSPITAL"
REPAIR OF AN AMPEG JUPITER AMPLIFIER HEAD
Not really a lot to say about this one and not very much needing doing either.
It had come in with a bad hum problem and not sounding too good.
It had obviously had previous work carried out and the
technician had done things the lazy way.....mounting the components on the
underside of the board!
I half-expected to be having to change some of these smoothing caps, but they were all fine!
I'm not a big fan of the PCB's used in these but....they do sound pretty good though. Here, I have also replaced the power-on switch as it wouldn't turn off.
The bottom cover
in-place. I also replaced many of the missing securing screws.
Though I hardly ever need one
myself, it is always a nice touch when the schematic is included on an amp.
Note the left
and right wooden panels which are rubber mounted for transportation cushioning. The
amp's chassis weight sits on these when it is the right way up in the case.
All that was wrong with her (apart from the faulty power switch) was one of the 7029A output tubes was completely shot.....causing the bad sound
and hum, due to in-balance in the output stage. A nice, slightly used but good pair of Fender-branded
tubes (GE's really) brought everything back to life, along with the normal service
and re-bias one would do on an amp.
Nice sounding amp though, and doing the full 50 watts RMS. Cool!