A728 - an MTP or a UMS device?

[Uxbridgebob]

I'm new to the MP3 "world", so please excuse what might be a daft question! We have an A728, and have tried connecting it via the USB port into our Samsung Home Cinema system, but it's not recognised at all.

We phoned Samsung, who asked if the Sony was an MTP device (won't work apparently!) or a UMS device (should work apparently!), and I'm not sure how to find out. If it is an MTP, can I change it to a UMS without losing the music on there?

Thanks!