The product is not expensive, the headphones seem to work properly. As I bought it to use the optical output, I'm a little disappointed. Sampling is announced 48khz or 44.1 but it is in fact not supported. The sound of the optical output (I could compare with the optical output of my desktop PC) is deaf, treble not apparent, really inaudible. I thought digital would be good, or it is unusable. The only reason I have not returned is that it would be annoying (or expensive) to return the as keep the .....