I've bought them a headphone amp, the HPA-100, a few moths ago and unfortunately due to health problems only took enough time to test it now.. I can clearly hear hum without any source. I tried to lift ground from mains with the same result. My cans are Sony MDR-7506. Initially I thought it was the high sensitivity of the Sony's but already tried with a friends old Onkyo's, much worse!
They still haven't replied my email about it, but I'm letting them have more time to do it cause it was sent only 2 days ago.
However I've had problems with repair of a DacMagic which was originally modded by them too. They sent the unit exactly like it was and charged a small price, probably because I asked if they could do a discount if I bought the headphone amp. It's hard to belive they don't have measurement tools to check a problem that was clearly visible on a frequency plot...
Edited by JhFi - 2/19/14 at 8:25am