Most AB blind tests that I've ever read about resulted in the test group not being able to distinguish between expensive tube amps down to moderately priced integrated AVR's. Even the diehard expensive group picked the cheap AVR when blind folded.

M80s VP180 4xM22ow 4xM3ic EP600 2xEP350
AnthemAVM60 Outlaw7700 EmoA500 Epson5040UB FluanceRT85