Just acquired an azatom Tune-Stream Bluetooth dongle which turns 30-pin iPod docking stations into Bluetooth devices. However, it doesn't work when I insert it in an Apple Universal Dock (connected to a TEAC micro hi-fi system via a small jack). My iPod Touch works in the Dock, and it pairs with the Tune-Stream remotely when that is in place, but no sound. Azatom instructions say doesn't work with speakers with "digital signal interface", but why would Universal Dock have a different interface from usual iPod docking station?
iOS devices can output either digital or analog audio through their dock connectors. Your hi-fi is only compatible with digital audio. But your Bluetooth dongle outputs analog audio to the hi-fi, which it can’t play.