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Another Problem with another Peavey Classic VTX 212 65 Watts
Hello people! I am new here, and on forums in general, so apologize if I do something incorrectly. (Any and all comments are welcome). Same goes for questions.
A short preamble:
I just bought an old Peavey Classic VTX combo built, I suppose, in the early '80s. (Am trying to find that out from Peavey, but they didn't reply to my e-mail yet in 4 days). The combo is in pretty good shape, all working, the lamps were not changed in about a dozen years (according to the previous owner), if ever (they are original Peavey). Allegedly never gigged, originally used at a guitar playing school, and then at home. Was just sitting collecting dust the past number of years.
I've searched and read about others on this forum having problems with the same gear, and my problem seems to be different.
The problem:
The Combo hums (like AC humming) quite strongly (loudly) in certain modes.
With guitar disconnected, and if all the effects are off, the humming is quite quiet, not disturbing at all. I'd say even natural, the kind one'd expect. In fact, if you turn up the Post Lead Gain, which, as I understand, acts as sort of Master volume on the High Gain channel, beyond 50%, the humming decreases significantly, almost to none.
However, if you switch on the Reverb (which itself works quite nicely), the humming increases significantly even on low reverb settings, (and low Pre and Post and Saturation) and increases drastically as you increase the reverb level, to levels which become very unpleasant. Increasing the EQ also adds to it -- i.e. increases the loudness of the humming. Increasing Phase also adds, but not as much.
With the guitar (early '80s Korean modified Squier Strat with 2 S & 1 HB) connected, all is the same, maybe a bit louder, as the guitar itself adds a bit, depending on how close it is to the amp.
Possible EMI:
I live in the country. The house is the last in a row of sort of townhouses, 5 in total, a converted cow barn.
)) No more houses around within 100 yeads/meters, just grass and trees. The nearest high voltage line is at least 200 yards/meters away. When checking, I unplugged all the appliances, the TV, stereo, PCs, etc.
Attempts to fix:
I've did some googling and reading also, and decided to start with changing the caps in the power supply circuitry. Found and downloaded the schematic, thanks to Enzo, and this web site.
This I did, with no effect -- the humming is the same with the new caps, as it was with old ones.
Question:
Can anyone help with fixing this problem? I have some basic, amateur skills in radio electronics, which are quite rusty, can more or less read the schematics. But, this is not enough. Do have a multimeter, but no access to an oscilloscope.
Looking forward to your kind advices.
Igor
A short preamble:
I just bought an old Peavey Classic VTX combo built, I suppose, in the early '80s. (Am trying to find that out from Peavey, but they didn't reply to my e-mail yet in 4 days). The combo is in pretty good shape, all working, the lamps were not changed in about a dozen years (according to the previous owner), if ever (they are original Peavey). Allegedly never gigged, originally used at a guitar playing school, and then at home. Was just sitting collecting dust the past number of years.
I've searched and read about others on this forum having problems with the same gear, and my problem seems to be different.
The problem:
The Combo hums (like AC humming) quite strongly (loudly) in certain modes.
With guitar disconnected, and if all the effects are off, the humming is quite quiet, not disturbing at all. I'd say even natural, the kind one'd expect. In fact, if you turn up the Post Lead Gain, which, as I understand, acts as sort of Master volume on the High Gain channel, beyond 50%, the humming decreases significantly, almost to none.
However, if you switch on the Reverb (which itself works quite nicely), the humming increases significantly even on low reverb settings, (and low Pre and Post and Saturation) and increases drastically as you increase the reverb level, to levels which become very unpleasant. Increasing the EQ also adds to it -- i.e. increases the loudness of the humming. Increasing Phase also adds, but not as much.
With the guitar (early '80s Korean modified Squier Strat with 2 S & 1 HB) connected, all is the same, maybe a bit louder, as the guitar itself adds a bit, depending on how close it is to the amp.
Possible EMI:
I live in the country. The house is the last in a row of sort of townhouses, 5 in total, a converted cow barn.
)) No more houses around within 100 yeads/meters, just grass and trees. The nearest high voltage line is at least 200 yards/meters away. When checking, I unplugged all the appliances, the TV, stereo, PCs, etc.Attempts to fix:
I've did some googling and reading also, and decided to start with changing the caps in the power supply circuitry. Found and downloaded the schematic, thanks to Enzo, and this web site.
This I did, with no effect -- the humming is the same with the new caps, as it was with old ones.
Question:
Can anyone help with fixing this problem? I have some basic, amateur skills in radio electronics, which are quite rusty, can more or less read the schematics. But, this is not enough. Do have a multimeter, but no access to an oscilloscope.
Looking forward to your kind advices.
Igor
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