Re: Need help on Peavey Standard 130 watt Power Module

Load the amp with an 8-ohm resistor. Input 1 KHz sine.
What does the trace look like? Any DC on the output?
Any crackling or spitting noises? Hum? Excessive
AC line current draw?

LV




Dr RaTsTaR wrote:

Hello,

I am attempting to repair a Peavey Standard 130 watt power module and
would appreciate some advice. I am not experienced in amplifier or
electronics repair but I have taken all the electronics courses that
the local Jr College (Mesa Jr. College, San Diego) had to offer. I
have a lot of theory but not any practical experience.

The amplifier will pass a music signal to the speaker when I patch an
audio signal directly into it, but the music is cracked and fuzzy,
very distorted. Here we have bypassed the pre-amp front end
completely. This unit is in a Standard Power Pak, which is a guitar
setup.

I have the schematics and have been poking around with a computer
sound card oscilloscope. I have also constructed a simple tone
generator so that I can use a stable signal to trace.

What would allow a simple amplifier like this to pass a signal, one
that is distorted? I have checked the main power transistors in
circuit using a diode checker on my Beckman DMM.

I recently successfully repaired a Peavey XR600E using this same diode
checker to identify the 3 blown transistors in the left side. I also
had the right channel to compare readings to, so that was a great
help.

Any help you can provide would be greatly appreciated.

Thank you.

d0ct0r RaTsTaR



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