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previous: Spencer Hi everyone, just finished my first... -- 8/27/2000 2:30 AM

Re: 1st amp power amp problems...

8/27/2000 3:20 AM
Tracy	Re: 1st amp power amp problems... Hi Spencer I think when your using negative feedback around the power tubes you have to ground the output trans through the chassis. I believe this should not be the star ground where the first input filter is. Your problem number three: the presence and resonance controls decouple the feedback loop, each in the high or low frequencies. you might try different values of feedback resistors or temporarily wire a one meg pot. find a good value and substitute a resistor. you do have a feedback resistor hooked to the phase inverter driver tube? Tracy

8/27/2000 3:20 AM

Tracy

Re: 1st amp power amp problems...

Hi Spencer

I think when your using negative feedback around the power tubes you have to ground the output trans through the chassis. I believe this should not be the star ground where the first input filter is.

Your problem number three: the presence and resonance controls decouple the feedback loop, each in the high or low frequencies. you might try different values of feedback resistors or temporarily wire a one meg pot. find a good value and substitute a resistor.

you do have a feedback resistor hooked to the phase inverter driver tube?

Tracy