Buy 2x USB extension cables, cut both in half, and connect female port's green/white wires to male plug's ones that goes into stereo and black/red ones to the plug that goes into your 1A USB adapter.
It doesn't sounds nice, tho (At least compared to ASUS Xonar Essence STX or it's closest competitor Creative SoundBlaster X-Fi Titanium HD). :3
(at least that's what theory says)
If you shit money - something based on SeaSonic's X-platform (for example, Corsair AX750/AX850)
If you don't - something based on any recent Great Wall's platform (for example, OCZ ZT 750W).