Using cheap, modern tubes (especially Russian) in very expensive amps does not make sense to me.
Worst offender? SOLDANO! That brittle, harsh Sovtek high end with an amp using NASA spec tolerances???
5881's instead of the nearly endless supply of 6P3S-E genuine military power tubes that sound night and day better?
Much of the dreaded ice-pick is no speaker break in, cheap tubes, and low bias. Fight me!