Anyone have the service manual/schematic for this thing? It would be interesting to see if there are bias trim pots, and then push the bias up to see if the distortion reduces..
As an aside, it seems at least one AVR manufacturer, Onkyo, is removing bias pots from current AB products, though they are in earlier year models. The Onkyo tx-rz720, which I have, shows the trim pots in the scheme, but as 'NM' (Not Mounted, I assume). They also are missing from the parts list. 'Interesting' solution to their earlier heat problems - under-bias and don't let anyone change it. Great engineering - reminds me of Honda's VCM - Variable Cylinder Management - garbage engineering...