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06-13-2023, 11:26 PM
(This post was last modified: 06-14-2023, 12:01 AM by talking_glowstick.)
Hi, I've recently built up a PSU-PRE and an M-Pre. I have partial success, but I'm having two issues and I've run out of things to check/know to troubleshoot.
1) In each channel, I get a good quality sound (clean in one, distortion in the other). However, the EQ doesn't work in either channel. The knobs make no difference as if the tone stack is completely defeated.
2) Also in each channel if I turn the volume up above 1 o'clock then it goes from normal-sounding to suddenly heavily clipped, fuzzy, lower volume. Playing harder makes it worse and tends to make it cut out entirely.
Of note:
This is a fully 'stock' 800 build, 12V heaters.
I've carefully triple-checked all my wiring.
I gently scratched between all joints, and then used alcohol and a plastic brush to clear any possible solder bridges.
I can power it up without tubes, through a PLSS with a 60W lamp and read 371 at the plate input, -12 at the heater input.
Changing tubes does not affect anything.
Does anyone with more experience have any suggestions about what else to check?
1) In each channel, I get a good quality sound (clean in one, distortion in the other). However, the EQ doesn't work in either channel. The knobs make no difference as if the tone stack is completely defeated.
2) Also in each channel if I turn the volume up above 1 o'clock then it goes from normal-sounding to suddenly heavily clipped, fuzzy, lower volume. Playing harder makes it worse and tends to make it cut out entirely.
Of note:
This is a fully 'stock' 800 build, 12V heaters.
I've carefully triple-checked all my wiring.
I gently scratched between all joints, and then used alcohol and a plastic brush to clear any possible solder bridges.
I can power it up without tubes, through a PLSS with a 60W lamp and read 371 at the plate input, -12 at the heater input.
Changing tubes does not affect anything.
Does anyone with more experience have any suggestions about what else to check?
