Tube Amp Archive

measuring across 9 and 4/5 i get 5.7 VAC

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 (Pin...

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

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?

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.

ok, i replaced the batteries and retested all of them, let me know if these look more reasonable: R10- end connected with C2: 338 VDC R10- end connected with Pin1: 141 VDC R13 end connected with C2: 338 VDC R13- end connected with Pin6: 5.4 VDC C8+: 332 VDC C13: tested several times and it switches ...

R10- end connected with C2: .0F (this means out of range on my multimeter) R10- end connected with Pin1: .17VDC R13: both ends read .0F C8+: 336 VDC C13: multimeter goes crazy then gives me a reading of 474.4 VDC R29: both ends read .0F All the AC voltages from V5,6,7 read 0.0 all preamp tubes are g...

martin manning wrote:Measure the DC voltage at the positive end of C2 and C7 and see what you get.

they both read 340 VDC.

the readings i got from V5 are way off from those:

Pin1: .14 VDC
Pin2: .57 VDC
Pin3: .002 VDC
Pin4: 0
Pin5: 0
Pin6: 2.7 VDC
Pin7: .02 VDC
Pin8: .001 VDC
Pin9: 0

and like i said before, the rest of my DC voltages are either low or unreadable, and all my AC voltages are coming back 0

i'm not sure what to make of the voltage readings i got (and there is a distinct possibility that i fucked up, never having done it before). But the DC voltages in V5 were extremely low, and the the DC voltages in V7 were so high they were unreadable by my multimeter. and V6 gace a mixture of low an...

What about on the board? Did you notice any place on the signal path where something changed? The signal near the input should be louder when probed because there is amplification of that signal downline. What about the grids? pins 2 and 7. . Places on the signal path where something take place whe...

while probing around and listening to ticks and pops i found several instances. a few pins on the PI gave light pops and noises when touched. but the most response i got was from pin 6 on the first preamp tube (V5 on the schematic). it gave off a fairly loud scratch/pop sound. does this sound like i...

No loop on the Butcher. The most common problem with those is the ribbon cable connecting the power tube board to the main board burns up. Look for burn spots on the cable connectors. Do the power tubes heat up? If the cable is bad they usually don't. Check all the fuses on the power supply board t...

Reeltarded wrote:Pull the PI and turn it on. Is the output still hummin a tune?

What the heck is a booster output?

Booster output goes out to another power amp to use as a slave.

pulled the PI. it still has a faint hum, but it was no longer affected by the post-gain pot. but i'm not sure what this tells me...?

yeah, i've tried a whole different set of pre-amp tubes.

good idea about about the PI, though. i'll check out the PCB again and look for components around the PI.

any other suggestions appreciated