I need some help with the hum that is coming through my speakers. I original setup: PC (Phantom Canyon NUC) -> USB (Supra Excaliber) -> DAC (Chord Qutest) -> RCA (Chord Clearway) -> HP amp (ifi Zen Can Signature 6XX) -> Balanced cable (custom 4.4mm to two 6.35mm jacks) -> Powered monitors...

I've recently purchased the Fostex TH900 Sapphire Blue headphones and am looking to get a dac and amp or dac/amp to compliment them. I've used the TH900's on my K5 dock with a Fiio X5iii in it and they sound fantastic, and they sound great through my Fiio E18 as well. I don't seem to notice...