Update   I did a diy USB cable made of 99.9% silver core and teflon sleeve. (0.50" diameter)  from left over DIY interconnect project (which I can't recommend enough).   feeding my dac, my silver usb sound way better than my audioquest cable      Then being left with the...

Thanks you Steeve   You just saved me $100...   Martin  

HI all   I recently bought a audiophile usb cable (audioquest coffee) to plug between my laptop and my soundcard. (modified D100 and HE-6 can)   the improvement is substansial. I only had the cheap generic usb cable before.   Since my songs are all loaded on a USB external hard...

Got mine yesterday. I analysed the circuit and can say that the output impedance is very low.   When you leave the DAC section, you pass a signal cap (wima), go thru a potentiometer and reach an op amp that feed a push pull emitter follower. Transistor stage are included in feedback loop...