Summary: I have owned the HK AVR-7200, AVR-8000 and both of them, especially the 8000 blew the 7550 away. It has enough power but the sound quality is not all that. Also the one I had was buggy with a intermittent problem with one channel suddenly getting louder then it should.
Summary: The sound from this unit is delightful; warm, full, and LOUD if you want it. HOWEVER, unless you are a seriously dedicated digital user, this unit will seem nearly impossible to use. If you are over 40 years old, and think this will be like setting up an ordinary stereo, then get something else! This puppy is a powerful computer with a boatload of power, and if you can't figure out how to tune the speakers (9 of them) it can be terribly frustrating.
Summary: The sound quality of this HK avr7550hd is excellent--very pleasant and listenable. I have used processor out to my HK990 integrated, and the preamp and DAC are impressive. The only outboard DAC I have is a MF V-DAC but the avr7750hd's DAC is clearly superior. I have used this avr to biamp my vintage AR9's as well. It is rated 110w x 2 and 100w x 7--very beefy amp. Network connectivity is my favorite feature.
Summary: A wonderful design possesing supersymetry like sphere or space. Definitely wondering the modulations of amplitudes (current) AM and frequencies (voltage) FM. Wish to had some more ears! Yet I believe it will sound rather different at each seat of the room or saloon for both tastes: Digital (split constant current) and analog (split constant frequency). In both cases AM and FM will take place simultanously yet sounding rather different at each part of the room or saloon.
Summary: I had an AVR-7550 for about 10 months and it was great. But, all good things must come to an end and it stopped working. First the rear channels went, then no sound at all. The warranty was still in effect. I brought it to the HK repair centre myslef. Once fixed, HK called and I asked that it be shipped. Well, UPS lost the receiver, I finally got their cheque and bought an ONKYO TX-NR-1009, a nine-channel 110 watts/channel receiver. Sounds a lot better!!