Hi Charles, Much appreciated on the kind words and I hope you are doing well! I went for the power supply having almost zero audible impact on the sound of the amplifier. Tube rectification, the 10H choke, film caps and Western Electric style noise cancelling on the cathodes of the 2A3, plus additional choke and Pi filter for the SRPP driver stage does a great job of isolating the signal from the power supply. I use DC filaments on the 2A3s with Schottky fast recovery diodes and vishay wire-wound resistors as a buffer before the first filter caps and between subsequent capacitor stages. All capacitors are very low ESR as well. In my experience this approach mutes the switching noise from the diodes, and the charging pulses the first capacitor has to absorb. Additionally the toroids provide excellent regulation and very low noise (plus zero magnetic field due to their construction). The reason I don't use AC is that the 60Hz hash from the wall still ends up across the audio signal and modulates at that frequency plus several octaves above and below and is audible. Many state that AC heaters provide a "lively" sound, or that DC "sucks the life" out of the sound, which may be true in each person's specific experience, however the modulation with AC is there and measurable and does introduce itself into the audio signal. With DC, if the charging spikes are minimized, and the cathode is decently isolated then you get a very quiet amplifier that does not have that AC modulation riding on the audio signal. Again, thank you very much for the kind words and noticing the various aspect of the build of this amplifier! Best regards, Aric