Ah, so I realise there are lots of variables here but initial pointers are (if/when the Rotel gets up and running again on the DB25 connector) I'm better putting the main five channels out to the 96,000µF Rotel instead of the 24,000µF Denon!
Although just edited as the Rotel's caps are a lot older than the Denons - try factoring that one in!
For any fellow geeks µ is ALT 230
@Mr Wolf @Conrad @AndreNewman I have some good news... my Rotel with the faulty RCA inputs, the £60 for the custom made DB25 was worth it, works faultlessly!
Picture in test rig, five channels connected, swap around speaker connections and prod, poke and shake