I use my 755 to run four channels of a 4-ch inline system, powering four CROWN ES 224. Each speaker has two 10 in. woofers and 24 electrostatic panels. These are known to soak up power and originally were "mated" to CROWN DC300s....and I was biamping. I had therefore four DC300a's. The improvement in sound quality when I removed the CROWNS and replaced them with the 755 was remarkable. So much cleaner. I think in part (and according to Scott & Steve) it is due to (1) more headroom; (2) more reserve power...unused but there. The 7500 will be even better. I bought the 7700 for my other system and it improved it as well. Hope this helps