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Dear Shannon, The Poseidons are up and running well. I noticed on the board a feature allowing the bypassing of the 12AX7 resistor. If done, this should decrease local feedback and raise the open loop gain some, giving greater overall feedback, yes? I wonder what the results might be and if any change in feedback resistors and compensation capacitors would be needed. I am seeking to maximize detail. (No tube rolling yet). Can you help here? thanks again for a great product! Bob

Hi Bob,

Without me popping a bypass cap in there to tune it up, I'm not sure how much things would change stability-wise. These tube amps with >15dB negative feedback are finely tuned beasts, and a little change could cause instability. That said, experimentation is part of the hobby, so give it a shot! Maybe square wave it if you can. For those that may have not noticed, the footprint is a small axial pad on the opposite side of the 1k resistor.

The reason I went without a bypass cap in this design was three-fold: 1) higher input Z, 2) lower output Z not necessary due to the driver input Z, and 3) more linear due to the local/regenerative feedback.

Thanks, Shannon. It looks like I'll leave it where it is and let the tube rollin' begin! Bob (smillin' big)