I'd also recommend the Quicksilver if you're looking for a tube headphone amp at a great price - I think it's just about $1000, and sounds like it should cost a lot more than that - hand-built in the US, too. Upgrade tubes for it are relatively inexpensive, and you could use some of what you saved from that $2500 to invest in an upgraded headphone cable...
@pastorbob - yeah, DAC burn-in is ridiculous, isn't it? When I got my Holo May DAC, I just turned it on and left it for about 3 weeks before I put it into my system - sounded awesome by then!!