I have this problem with a noise coming from the speaker. Let me wxplain: The amp was purchased used (e-bay), not sure how old it is or if it is still covered under the 5 year warranty. Serial number is E25-2731. Anyone point me to a serial number decoder or can tell me if its still covered?
The noise is definately coming from the speaker, and is a "buzz" like a very low volume distortion that kinda peaks as the note is fading. This will happen on only certain notes. I did replace the power tubes with some Groove Tubes EL84-S with a 6 rating. This stopped the problem for a bit, maybe 2 months, although my son reminds me that the original noise I was hearing was more of a rumbling/wavering noise on some sustained notes... Now this buzz noise is back, prompting me to think that something else is going on. I grabbed a full set of pre-amp tubes from my son's collection and swapped them out, noise is still there.
My son says I'm crazy, but it really sucks to hit a note that you want to sustain, and all I can focus on is that friggin noise that slowly develops, peaks, and fades away.
It reminds me of those cicada bugs you here in the summer months buzzing up in the trees.... Not as loud and under the note, but Really annoying.
Someone mentioned a grid resistor that may be bad. Where can I get a schematic for the board? And I wonder if this is the problem (bad resistor) that it would reappear 2 months after replacing the tubes. I would have expected that the noise would be there all the time, even with new tubes....
Any help would be really helpful.
Thanks
The noise is definately coming from the speaker, and is a "buzz" like a very low volume distortion that kinda peaks as the note is fading. This will happen on only certain notes. I did replace the power tubes with some Groove Tubes EL84-S with a 6 rating. This stopped the problem for a bit, maybe 2 months, although my son reminds me that the original noise I was hearing was more of a rumbling/wavering noise on some sustained notes... Now this buzz noise is back, prompting me to think that something else is going on. I grabbed a full set of pre-amp tubes from my son's collection and swapped them out, noise is still there.
My son says I'm crazy, but it really sucks to hit a note that you want to sustain, and all I can focus on is that friggin noise that slowly develops, peaks, and fades away.
It reminds me of those cicada bugs you here in the summer months buzzing up in the trees.... Not as loud and under the note, but Really annoying.
Someone mentioned a grid resistor that may be bad. Where can I get a schematic for the board? And I wonder if this is the problem (bad resistor) that it would reappear 2 months after replacing the tubes. I would have expected that the noise would be there all the time, even with new tubes....
Any help would be really helpful.
Thanks