That’s an interesting question. You probably will get a different perspective if you ask this on ASR website where people are more attuned to measurement than here on Audiogon. I certainly don’t have the answer. I usually use both my ears and measurements to differentiate between gears. My ears being the ultimate arbiter. I too believe in science by trade.
Tube vs Solid State Amp measured with REW
I have both a tube amp (Masterworks SET 300b) and a solid state amp (Arcam A32), with Klipsch Forte 4 speakers. The Masterworks sounds much better; more clear, very lifelike. But when I measure with REW the frequency response and THD are about the same (albeit with some variations over the range). Is there any other parameter that causes one amp to sound better than the other, that doesn't show up on the measurements?