^ Thank you!
I found some US buying options at eBay by searching "USB Type A Female to Micro USB Male Host OTG Micro USB Female Y":
It would be even better, if the host OTG plug is angled (I searched but could not find any).
All of those look to be suitable to me.
The only thing I've noticed after a test last night is that i suffered some level of 'buffering' as the HD seemed to struggle to keep up with the DAP.
I was using a Kindle charger last night so assumed (probably incorrectly) that it was relatively low powered. I'm hoping that when i retest today with a samsung charger i'll have a better experience.
Its a power issue, or a scanning issue.