Unfortunately, I've sold off most of my gear since I decided to get a one-box solution. So far I've tried them through my iphone 5, Macbook Pro, iphone -> Arrow 3G and B&W MM-1 which has an built-in DAC. Haven't noticed any hiss or anything. I'll go to my local shop tomorrow and see how they pair with the AK120 and ZX1. Also, I'll be attending the Highend show in Munich next week where they'll have the AK240 and HUGO. So definitely looking forward to that. What is your setup?