Oh. I thought that maybe you were trying to power it off USB.
Assuming the drive works elsewhere, I have no idea why it wouldn't work with the adapter.
My guess is that it's one of those with the metal rod jumpers inside. It should be pretty easy if somebody can tell you where the jumpers should go.
I'm not really an expert though, so don't trust what I said.
QFT.
I'm waiting for comparisons against the SR-007. Since the HD800 looks to be a poor choice for summer headphones, I'll only be buying a pair if I like them more than the SR-007 overall.
Thanks for the info. I guess the Grados, K501, or DT880 would make better summer headphones then. Too bad I prefer the sound of the O2, K701, and HD650.