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So I have a Peavey Classic "B", ss preamp, 2 6L6 output section, alot like the Music man amps.
The PI driver section is acting odd, not amplifying properly, just kind of spitting out pulses to the output tubes that come and go.
Drivers are good, all componenets in the PI circuit test good.
I remembered seeing the same problem with a Music Man amp that had a bad 24v supply to the PI driver transistors.
Sure enough, lowering the voltage input with a variac brought the voltages where they were supposed to be and it's amplifying beautifully. Jumpered in a Zener to hold it's 24v supply steady and it's fine with proper line voltage.
The PI driver section is acting odd, not amplifying properly, just kind of spitting out pulses to the output tubes that come and go.
Drivers are good, all componenets in the PI circuit test good.
I remembered seeing the same problem with a Music Man amp that had a bad 24v supply to the PI driver transistors.
Sure enough, lowering the voltage input with a variac brought the voltages where they were supposed to be and it's amplifying beautifully. Jumpered in a Zener to hold it's 24v supply steady and it's fine with proper line voltage.