Peavey Butcher Repair

[martin manning]

Looks like R13 is all but open. Try measuring the resistance across it with the power off, and measure R10 while you're at it.

Maybe 500V is the limit of your meter.

[BenSC]

yeah, the manual says 500v is the max.

neither of those resistors give a reading. i'll see if i have any 100k resistors in my backstock or i'll pick some up tomorrow.

[BenSC]

ok. i changed those 2 resistors and it now passes a signal!

BUT, the output is very low. like, really low, and no overdrive crunch like it had previously.

anything else i should measure?

[martin manning]

OK, cool. Let's see where you are now- check voltages to ground on pins 1, 2, 3, and 6, 7, 8 on all the preamp tubes.

[BenSC]

ok, retested them:

V5
pin1: .0F
Pin2: .36
Pin3: tested it several times and got reading of both 0 and 2.07 VDC
Pin6: .0F
Pin7: .015
Pin8: .001

V6
Pin1: .0F
Pin2: .01
Pin3: .7
Pin6: .0F
Pin7: .0F
Pin8: .0F

V7: all pins gave .0F reading

[martin manning]

I can't help but think your meter is going south. I couldn't understand the 0VAC reading for the filament voltage earlier, given that the filaments are obviously on. Do I understand correctly that you measured across pins 9 and 4 (or 5) on the preamp tubes and got zero? Try measuring some known quantities like the line voltage coming in to the chassis as suggested earlier (measure across the hot and neutral, not to ground), and see what you get there. For DC, measure some batteries like a 9V and a 1.5V AA cell. Diagnosing problems will be very difficult with a flaky mater!

[BenSC]

i tested the line voltage: 122 VAC
tested some batteries and everything checked out.

i needed a better multimeter, one for measuring capacitance, so i bought this one about 3 weeks ago, wasn't cheap either. it's not impossibly, but i don't think it is the multimeter.

when i test the AC voltages (Pins 4,5 and 9) what typically happens is the numbers jump around, the sequence usually goes something like 9.9 VAC > .0F > 0.0

and some pins give 3.2 VAC > .0F > 0.0

[martin manning]

Measuring across pins 9 and 4/5 I would expect ~6.3 VAC, and from 9 or 4/5 to ground, half of that, ~3.2 VAC. Your meter gets something close and then shows out of range and then zero. Pins 7 and 8 on V6 should be around 200V, and pin 6 should be the same as the voltage at the positive end of C7 and C8, and your meter is showing out of range on all of these. Same with pin 1, and pins 1 and 6 on V5. All of this plus jumpy readings or various readings from the same pin would seem to indicate the meter is malfunctioning. Do you have access to another one?

[BenSC]

measuring across 9 and 4/5 i get 5.7 VAC