The HD650 sound beautiful with the RCA monoplates, though. It's close. The RCA's have an awesome low end. Almost three-dimensional like in its impact. While the "mystery" tube opens up the HD650 at the top quite a bit. Like the "veil" never existed. Two extremely smooth tubes yet with different focuses in the tonal spectrum.
Lovin' the RCA monoplates with the W3000ANV, LCD2.1 and HE500. Surprisingly, the LCD3 and HD800 don't sound as special. Maybe it has something to do with their slightly recessed midrange that the RCA's are emphasizing even more. Or it could be my ears.
Is it worth getting the HD650 if I already have the HD800? I could use a more relaxed change up at times, the HD800 commands my attention when I listen to it.