Well, I received my Crown XLI 1502 a day early. I bought the Class A/B amp (less expensive) as I knew it would have very good performance with high slew rate devices, unlimited power and headroom for my use and it didn't need any space for cooling. I will most likely never have the fan turn on as most others who have used this unit never got the fans on either. It is like the amps you guys have in your two channel setups, very heavy to me after dealing with light receivers! It is about a 30 pound monster and all it does is amplify. The transformer is massive. You can get the same power level in a Class D amp for a few hundred more dollars and about half the weight. I just have never played with a Class D amp and didn't want to risk not getting the best audio performance I could. I plugged it in and did my normal 30 minutes of troubleshooting getting the gains set right and all. Also, the input switch is set at .775 volts for consumer gear and not the 1.2 something for pro-audio. I had to manhandle the amp into my totally cost free rack. It sits on the carpet with my Yamaha receiver on top of it and my CD player on top of that. Not pretty but it gets the job done.
I have the amp gains at 100% and it mates perfectly with the Yamaha. I did a lot of work on getting the Yamaha sorted out the last week and I found the amazing "Pure Direct" button has a HUGE and I mean HUGE effect on the 2 channel music listening. It's like going from a hand held transistor radio from 30 years ago to WHAM! a real live honest to goodness freaking awesome studio live sound. It bypasses all of the Yamaha internal pre-amp sound shaping crap, I mean stuff and gives you your source info with zero adds or subtracts. It really works. So, I first noticed right off the bat that the volume level that I was using for 2 channel was now much less. I have the volume control set for 0-99 for the range and normally on two channel I'm up around 50. That dropped about 15 points. So I will have to go through the entire surround side of my Yamaha and fix the levels for movies. But on the 2 channel Pure Direct it is all set and works very, very well.
I knew that a lot of people would want to know if there is any hiss or other noise in the speakers from the new amp. I turned the receiver up to 50 which is around 90 db (very loud) and cut the bluetooth signal. Dead silent. There is no audible hiss or any other noise come from the ESL speakers, it is as if I turned everything off. Also people worry about the strong magnetic field that may affect the Yamaha from the Crown as it can supposedly cause ground loops hum and other issues. There is nothing at all. Just pure clean music. This is with it set up in the worst possible way. My Yamaha sitting right on top of the Crown with about a 1/8th of an inch gap. I'm using cheap Chinese $2.00 RCA connections for my interconnects. Everything should scream "problems". But luckily there is no problems and no noise/no issues.
So, I have to say it works fantastic and with my ultra cheap setup, there are no issues at all. I can easily recommend this for any need where someone wants unlimited power and unlimited headroom. My Yamaha now has unlimited power for my center and two surrounds (5.1). But, I don't listen at super loud levels as I like my hearing! I have nothing negative to say about this experiment. It was 100% successful and seems like an inexpensive way to get more power for those who need it.
Oh and I now have the power to safely push my ESL speakers to ridiculous levels on Edgar Winters Frankenstein music. I really pushed those panels fairly hard and it said, "hey! No problem, do you want more?" I then said "Heck NO I can't take it any louder without busting an eardrum!" I gave up before the speakers did. I would never push that hard with just the Yamaha as I would be afraid of clipping the hell out of it. I am not into having to repair my ESL's! Well, I hope I answered many of the questions that any of you may have had.