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Hey guys,
I'm working on an Ampeg SVT-4 PRO that had a pretty catastrophic meltdown. There was no output and a bunch of bad components. I'm getting output now, but the sound is distorted on Power Amp A out.
I've replaced output ICs Q110, Q112, Q114, Q116, and Q118, as well as the corresponding 47 ohm resistors. Power resistors R139, R146, R152, R158, and R164, as well as the corresponding 1.5k resistors on each. Q102 and Q105 have been replaced. Q103 and Q104 have been replaced. R118 was burned and replaced.
My issue now is that i'm getting 0vdc at A_HI and A_LO, and 3.9vdc, + and -, at B_HI and B_LO. Am i right in thinking it's missing the bias voltage? What could be the likely culprit?
http://bmamps.com/Schematics/ampeg/A...t_4pro_sch.pdf
I'm working on an Ampeg SVT-4 PRO that had a pretty catastrophic meltdown. There was no output and a bunch of bad components. I'm getting output now, but the sound is distorted on Power Amp A out.
I've replaced output ICs Q110, Q112, Q114, Q116, and Q118, as well as the corresponding 47 ohm resistors. Power resistors R139, R146, R152, R158, and R164, as well as the corresponding 1.5k resistors on each. Q102 and Q105 have been replaced. Q103 and Q104 have been replaced. R118 was burned and replaced.
My issue now is that i'm getting 0vdc at A_HI and A_LO, and 3.9vdc, + and -, at B_HI and B_LO. Am i right in thinking it's missing the bias voltage? What could be the likely culprit?
http://bmamps.com/Schematics/ampeg/A...t_4pro_sch.pdf
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