SlumberjackThanks for your answer! ...I read about some audio output pins (cheaper dock connectors make use of them) and some digital pins for the usb connection - DAC connector docks, like the onkyo ND-S1, make use of the "bits and bytes" to create a digital (some even an optical) signal. So i hoped to get rid of the intern ipod DAC, connecting the iPod via USB to some "smart" nicesounding device. The combination "iPod-Onkyo-xDuoo-Headphones" don't sound that smart to me... so I still be searching!