Equipment used: Headphones: RHA T20, AKG K7XX, LCD-2f, RE-400, HD-650, HE-560 Firmware: 2.003 Amp Cards used: Minibox Gold, Elfidelity Balanced Music used: From Röyksopp to Amber Rubarth, Diana Krall to Apoptygma Berzerk, Tom Jones to Sphongle, Yello to Camouflage, mostly FLACs 24/96 or 16/44.1 – some mp3 320kbps, some AAC 256kbps Depending on headphone high … Continue reading HIFIMAN HM901s Portable Music Player Review