I am awaiting the arrival of my second child and have decided that now is the time to invest in a decent headphone amplifier rather than having ongoing battles with SWMBO. I have been toying with the idea of valves and am quite interested in the stuff available from China which looks pretty good. Does anyone have any experience with any of the chinese stuff (If not headphone amps just general stuff)? I have a few concerns about voltage/safety but mostly sound quality. I use HD580s and they could do with warming up a bit. Any thoughts?