The soundcard has really good sound that is not an issue at all. However even though I am using the optical cable it "beeps and squeaks" really bad once the volume is increased above circa 40%. And yes, it is the SMSL not the headphones. I've tried multiple headphones and speakers which are fine elsewhere. I thought that SMSL should have imbedded circuit cleaners for preventing this exact thing to happen.
Great quality for that price