Hello, the sound of my Asus Xonar Essence STX, connected to an Edifier 2.1 Box Set, has once been brilliant. Recently, the sound has increasingly lost dynamics and turned more and more "flat" and lifeless. Is it possible, that this caused by an unstable power supply unit (since other things, that may point to this, such as temporarily irresponsive or "disappearing" HDs, happened in the same time)? Or could power supply problems only lead to the card not working at all? Thanks