Happy Holidays! If I get the Sony repaired, it definitely won't replace the Marantz as it has the inputs and outputs I need, and supports HD digital audio and lossless surround formats. I might continue to use the Sony for amplification (would have to for a while to test the repair), but since 5.1 or 7.1 is off in the future and the units are still in demand, I'd probably sell it. They do seem to have decent resale value ($1k in the blue book here) which I can only attribute to using it as a 5 or 7 channel surround amp since the decoding is out-of-date, no HDMI inputs (only dual DVI), etc. Plus it looks impressive. :-)
I read that Sony developed these "S-master" digital amps using B&W 801s as their reference speakers and the sound is fine and hasn't tempted me to replace it so far. The Nakamichi PA-7 sounds great as well. They do sound subtly different -- the Nak sounds warmer and the bass is a little more pronounced which I actually like (that's the only way I can describe it -- both rattle the house with an action movie or the organ symphony) but the Sony's imaging is slightly better -- the Nak sometimes makes me wish for a center speaker. Also, the Sony runs a lot cooler (the Nak gets very warm just idling). But it's a waste using only 2 of the 7 Sony amps and I worry about the low speaker impedance which dips well below 4 ohms. I do bi-wire and considered using 4 of the Sony's amps but couldn't figure out a setting to do that. Then after it broke, I realized I can just split the input signal since all the amps are supposedly the same. Duh. I'd like to try that but then I suspect the power supply might be the limiting factor.
At this point, I'm thinking I will send it off for service. I guess I'll be out $100 if it can't be fixed but broken ones seem to sell, so I can probably get that back.
Thanks for taking the time to reply.Much appreciated.