Used is OK. I would prefer to get something higher end in the used market, rather than paying full retail for a lesser quality amp.
I have posted that I am also trying to use my Onkyo HT520 AVR for a headphone amp. This isn't a double post. I want to find out what my options are, so I am gathering information on different methods of powering my cans, so that I can make a better informed decision.
Right now I have Sennheiser PC 350 Gaming Headset. However, my plans are either Grado SR60i, or perhaps Senn. 650, if I can swing the $.
So, while these are gaming headsets, they suffice for music for now. I am looking for an above average sounding headphone set up. I am not an audiophile, as I don't have that kind of cash, but I do like good sound. Music will be my primary use for the future cans.