Its probably not still under warranty, i've had this system for about 4 years. But I will check the amp, but I'm pretty sure it's the dac, sometimes it works, sometimes it doesn't. I think it's got faulty wiring or something. 

Hello,   I have a shanling PH1000  and a hi-fi digital audio Super Pro Dac. It is connected with tributary interconnects and they power my HD 600's. It has all been working just fine until about a month ago. The dac has two lights on them called Power on which lights up, and a light above...