I'm planning to upgrade my current PC to a new and more silent one. Currently I have an Asus Xonar Essence STX installed to power my Sennheiser HD650 phones. But I'm thinking about selling the STX and buy the Essence One, as it would make it easier to find space in the chassis of the new pc when two (passive) gpu's are installed.
How is the sound-quality of the One vs STX? Does it sound much different, and would it be able to amp the HD650?