What I meant was, use the config to tell it you have a G68, HD621 and a pair of 5000's and set the 5000 as the controller, then see if the remote works via the HD621.
In other words try an trick it.
so config it with a G68, HD621 and DSP5000 but have it physically configured with the 512 plugged into the HD621 plugged into the DSP33's? I'll give it a go tomorrow, but I'm not sure I can see why it would work.
I feel like it might work if I can set the HD621 as a controller... maybe.
of course, if we knew how to wire a D5 cable, then I could let the DSP33's be the controller...