Bought a new DAC (DSPeaker Anti-Mode 2.0 Dual Core) that has a mini B female input (in a very tight space). Was worried that any adapter wouldn't fit, but it works perfectly, allowing me to continue using my type A male to type B male (standard) USB cable, the combination sounding much better than the cheap USB cable that came with the DAC.
PROS: Inexpensive, cheap shipping, provides a solid grip, does not seem to limit sound quality.
CONS: Small enough to easily get lost (but it had to be to fit).
Works. Looks decently made--the plastic overmold fits tightly around the connectors, nothing is loose or bent. If you have a USB cable with standard B male end and you need it to have a mini-B male end, this will do the job.