Quote:
Originally Posted by RichardGM
Quote:
Originally Posted by etherman
Despite some health issues, my attention is back to the amplifier. On listening, the first (built) channel is louder than the newer one. This is easy to confirm by ear.
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When you say louder, do you mean greater maximum loudness (which could indeed be affected by the DC operating conditions) or louder output for the same input? The latter would imply different gain, suggesting some inadvertently different component values in the feedback system. |
I meant louder output for the same input. I swapped input cables (to rule out signal level), then I swapped speakers, and the result was the same. I guess the different brand tubes need to be biased differently or one tube is grossly off spec, based on a quick observation, that one pentode is drawing more current than the other. I hope I will be able to make further tests soon and may be use a different pair of PCL86s from my stock.