Is anyone aware of an objective and repeatable comparison between a
valve amplifier and a reasonable transitor amplifier, operating well
away from clipping, where the difference was significant and
overwhelmingly in favour of the valve amplifier. To be useful the valve
amplifier would need to be relatively cheap and use currently
manufactured parts. The speakers would need to be fairly common and not
present a difficult load. The source would need to be accurate and
repeatable.