Hi Ron,
I am SO glad to hear that you're really enjoying your new Yamamoto A-08 amplifier! I, too, think that this unit is rather special.
And yes, it is rather surprising how much more powerful it sounds than most 2A3 SETs - and even some 300B SETs - even though the A-08 does not drive the 45 output tubes all that hard or rely on some of the new "turbo-charged" 45 designs that have recently hit the market.
Speaking of which, what brand of NOS 45s did Yamamoto supply with your A-08?
As far as my new A-09 amplifier goes, I am REALLY looking forward to listening to it in combination with Yamamoto's new CA-04 tube preamplifier, along with some of my more efficient loudspeakers (perhaps the Audio Note AN-J ... or the DeVore Fidelity Gibbon 8, which was voiced using the designer's own 300B SETs). More often than not, I prefer the sound of 45s to 300Bs, but the Japanese DO seem to have a way with 300Bs, and Mr. Yamamoto considers the new A-09 to be his flagship amp, so it will be very interesting to compare the A-09 to the A-08...
Cheers,
Brian
Venus Hi-Fi