Originally Posted by fermelom
I think that the HM901 is a more versatile player than the Tera. If you want to compare SQ you should consider the Tera only plays wav files and it's output is intended for iems
. Meanwhile the HM901 plays most audio formats and has swappable amp section (in general has a more powerful output) that can run full size cans. I haven't hear a Tera but think of it like the "nano" version of a high end portable player.
Tera has advantages (size, battery life, easiness of use, stability, signature sound) but 901 is indeed more versatile. The output is actually intended for portable headphones such as the Porta Pro, and it works also with iems, but ONLY high impedance iems and certain dynamics / hybrids. Otherwise capacitators in the output stage causes MASSIVE bass roll off with most low impedance BA.