@knighttodd "With the right music and recording they sound fantastic.".
You may have answered your own question. Nice amps, nice Preamp. Decent tubes in stock form. Your PL EVO400s with EL34s are fairly smooth. EL34s, no?
Some early Aerosmith Columbia recordings were known to be "too bright". A common complaint. Try a Remastered version, same tracks, does it get any better?