I have (hopefully) wrapped up my repairs on this amp. Back two or three months ago, there were several folks posting with problems on theirs, which were kinda similar to what I found. So here's a summary of what I did...hopefully this will help somebody out in the future.
First, about the amp. This amp is all-tube, with a pair of 6L6GC's for output. There's a 12AX7 for the PI, a 12AT7 for the reverb driver, and another 3 12AX7's for various gain stages. It's listed as 3 channel (clean, crunch, ultra gain) though the 3rd channel is merely a different gain setting on the crunch side. It dates back to the late 80's and apparently it got quite favorable reviews back then. Mine's a combo with a 12 inch Scorpion speaker, and like all older Peavey amps, it weighs a ton. There's diode rectifiers and one transistor--it drives the standby LED. Channel switching uses relays.
My amp already had the crunch channel diodes-bypass mod and the EQ-enable mod. (These are detailed in the Harmony Central reviews).
The symptoms: Fluctuating power/gain outputs. Gain was sometimes nonexistant, other times deafening. Reverb cut out. And the hiss, even at idle, was quite unbearable.
My goals: first, repair the problem areas. Second, make it reliable. Third, remove the hiss if possible. I was generally pleased with the tone when the amp seemed to work right, so after thinking about it a while, I didn't see a need for any "tone" mods. I gave up on the idea of adding a choke on the PS or adding screen resistors.
...more in my next posting...
First, about the amp. This amp is all-tube, with a pair of 6L6GC's for output. There's a 12AX7 for the PI, a 12AT7 for the reverb driver, and another 3 12AX7's for various gain stages. It's listed as 3 channel (clean, crunch, ultra gain) though the 3rd channel is merely a different gain setting on the crunch side. It dates back to the late 80's and apparently it got quite favorable reviews back then. Mine's a combo with a 12 inch Scorpion speaker, and like all older Peavey amps, it weighs a ton. There's diode rectifiers and one transistor--it drives the standby LED. Channel switching uses relays.
My amp already had the crunch channel diodes-bypass mod and the EQ-enable mod. (These are detailed in the Harmony Central reviews).
The symptoms: Fluctuating power/gain outputs. Gain was sometimes nonexistant, other times deafening. Reverb cut out. And the hiss, even at idle, was quite unbearable.
My goals: first, repair the problem areas. Second, make it reliable. Third, remove the hiss if possible. I was generally pleased with the tone when the amp seemed to work right, so after thinking about it a while, I didn't see a need for any "tone" mods. I gave up on the idea of adding a choke on the PS or adding screen resistors.
...more in my next posting...
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