Love this app on the phone sometimes...restarting reply....The LX57 is our 1523/SC75.One member here just bought the 1523 while it was $1000(would assume somebody else did as well).His only nit-pick is it looses a lot of power 5.1 to 5.1 + zone 2 use.(and not that it is underpowered, just requires it to be turned up quite a bit further than expected).I would be willing to bet the LX77 has a more robust power supply, more like the LX97(right model number?).Our SC79 had no issues running 7 channels(I never ran it on 9, when I connected the Thiele, it was as a 2nd zone. But I wasn't going to try a 7 channel soundtrack at the same time I was asking it to pound out some Felix Hell on a 4ohm load. I wouldn't task any AVR with that).