The usb's 16bit/48kHz limit can be overcome by using a digital coaxial cable (toslink cable), paired to a 3.5 mm adapter I've read. That'll give you 24 bit/96kHz. The cable and adapter cost about 10 USD.
EDIT: This only works mostly on MACs. Also don't buy a toslink and adapter, buy a toslink to toslink mini cable if you're on a mac, as Joementor, another user pointed out
EDIT: This only works mostly on MACs. Also don't buy a toslink and adapter, buy a toslink to toslink mini cable if you're on a mac, as Joementor, another user pointed out