@shadorne , @transience, I too expected my very mellow balanced tube preamp to tame the highly analytical M6S for a perfect match. On SOME recordings -- notably those originally analog mastered -- it works splendidly despite subsequent remastering. (Example: Keith Olson's 1975 "Fleetwood Mac" eponymous album remastered in 2017). But on more recent, digitally mastered material with substantial high-frequency content, the M6S's 768 upsampling screams like a banshee, cackling right past the tubes when coupled with RCA-terminal coax. Have not yet tried using USB or optical (M6S has no AES input), but if those don't tame it, I've got serious trouble.
Any hints? Maybe I will start a new thread if a different coupling doesn't help.
