Tube Amp connections : 0V vs EARTH vs HEAT vs CURRENT

[ccaudle]

The addition of the 1M to the PI did nothing at all to the sound. Same distortion.

Have you tried disconnecting the phase inverter from the power stage to see if the power stage is loading the PI in an asymmetrical way to cause early clipping?

 

[systemtruck]

Have you tried disconnecting the phase inverter from the power stage to see if the power stage is loading the PI in an asymmetrical way to cause early clipping?

I suppose just kill the connections after the C39 and C40 bypass caps and monitor the audio of either one of those leads? Do both those leads need to be dummy loaded down with some specific value so that the PI performs as it should? Or will the PI outputs perform just fine without any load other than an audio connection? And if so, what input impedance will i need for the audio input? My interface has 15k by default, but maybe i can add something more substantial like a series 200k so that I’m not loading down the PI output. It’ll create a voltage divider but it’s probably still plenty loud.