back to the highjack
Highjack:
Are the tubes in the pre-amp or power section?
For either location check the filament voltage, typically 6.3V. If it's too high the filaments will erode prematurely. Indicator will be tube no longer glows.
If the tubes in the power amp are going out the plate current may be set too high causing plate damage. The tubes will still glow but distort or not pass sound signal.
You should be able to adjust the plate current. The filament voltage may be directly off the transformer in which case adjusting it is not easy.
these are power with tubes in pre amp and power amp sections...no cooling device either...heat sinks came later also
mostly, if you were a guitarist, you didn't want the tubes brand new, you wanted them a little fried
I always liked the sound of new matched tubes, and I really never understood that "dirty" sound most guitarists went for
the "fuzz box" didn't get the same dirty sound as some fried tubes in one of these amplifiers
for instruments, I've had fender amps, marshall amps, gracen amps (the worst) custom amp, ( I think this is the first solid state amp for guitar)
the best of any of these was a tiny little amplifier in a wood box...the boogie amp...it cost a fortune back then, but it smoked anything I ever had or heard
that aside, my favorite amp was that sound city
the tone control was so pure, if you turned the bass mid and treble to zero, there was no sound
you guys ever see an old sound city or boogie amp, even if they don't work, pay any price for them and fix em up
gonna start a
new thread