The sound: it’s spectacular! Compared to a Stax SRM-007tii with 60’s Mazda Brimar 6CG7’s or 50’s RCA long black plates with D getters, the sound is far more relaxed, analog, detailed, expansive, dynamic and musically involving. I can’t wait to get some NOS EL34’s in here. The Berkeley Reference DAC shows off the Megatron’s speed and transparency; the DAC and Megatron are both detail monsters. The Megatron is a far more capable amp when connected to the Berkeley Reference DAC than a current low-noise, low-distortion reference amp, such as the Topping A90, which I also have.
The balanced inputs: dead quiet - perfect with the Wireworld Platinum 8 series XLR interconnects.
The voltage gain: I can’t imagine needing any more gain than I’m getting with the 1958 Holland D foil getter E180CC’s (thanks to the community for the tip on these) and the 1948 RCA 5751 triple mica black plates. I will say that this amp takes a solid hour to warm up, however.
Temperature: just touched 126F on the exterior of the right transformer case after a couple of hours - the internal temperature was typically within a couple of degrees when previously measured, likely due to the machined vents around the tubes. SMALL UPDATE: Kevin suggested some whisper fans to deal with the heat buildup; this is an excellent idea.
Hum: there is none whatsoever, there is only dead silence, irrespective of where the pot is positioned - it’s absolutely impossible to tell whether the Megatron is on, when powered from a current-gen PS Audio regenerator set to 120V.
Definitely T2 level stuff!
I CANNOT THANK KEVIN ENOUGH