I'm in agreement with the others. Start with 80 and try different combos to get the best sound. My thought also-if you can't tell any difference at different settings, then stay with 80.

I'm also very interested in your thoughts on the 7125. I've been looking and thinking about that amp but I'm concerned about whether it will make any difference from my Yamaha 657. $900 is alot for me to spend unless I'm going to notice a significant difference in sound quality or levels.