Good morning everyone.
I have a Fender 75 amp that I recently purchased. This amp worked when I got it but sounded funny (ugly distortion on bass notes or hard chording)
I opened it up and saw that three of the cathode bypass caps appeared to be leaking. I replaced all the cathode bypass and filter caps as a precautionary measure as they all were dated 1979.
It worked and sounded much better (It's been a week but only sporadically playing through it) until last night when it developed a loud hum.
Symptoms:
No hum in standby
Loud hum with all knobs at 1 (or zero).
Very minor volume change when rotating master volume control but only responds (and very subtle response) to this control.
Hum is still present with power tubes removed although much quieter.
Hum is still present with all tubes removed.
Thanks in advance for any help.
Added Schematic
GordB
I have a Fender 75 amp that I recently purchased. This amp worked when I got it but sounded funny (ugly distortion on bass notes or hard chording)
I opened it up and saw that three of the cathode bypass caps appeared to be leaking. I replaced all the cathode bypass and filter caps as a precautionary measure as they all were dated 1979.
It worked and sounded much better (It's been a week but only sporadically playing through it) until last night when it developed a loud hum.
Symptoms:
No hum in standby
Loud hum with all knobs at 1 (or zero).
Very minor volume change when rotating master volume control but only responds (and very subtle response) to this control.
Hum is still present with power tubes removed although much quieter.
Hum is still present with all tubes removed.
Thanks in advance for any help.
Added Schematic
GordB
Comment