Chris, you are quite right, those " minute irregularities " and some dirt and noise belong to live music and neccessarily have to be reproduced if the facsimile of the thing is to be believable. Only, you find a lack of that both in SS as well as tube gear, as was quite rightly pointed out above. Look up the concept of PRAT in these pages if you like and you'll see that this is an old topic, which has been discussed many times.
Cheers,
Detlof
Cheers,
Detlof