Gene, excellent description, thanks!
It really is a wonderful device, isn't it. It gets really fun when you connect it to front end components that have switching capability as well. Time to play find the signal (the 2 output options make it even more fun).
I did have some minor problems, but they can be attributed to a convoluted setup, for the most part. Here details:
Initial setup was preamp duty. Source was a Ti-book > usb > Yamaha DP-u50 > glass > Behringer DEQ2496 > 30' AES cable > Grace M902 > 10" interconnects > active x-over > Carver amps (bi-block config) >< subs and sats. The Yamaha was only in there to get me from the laptop to the DEQ, which is a required component. It has room corrections, as well as the correction curves for all of my headphones. Results were disappointing. The s-lock would cycle every 2 seconds, and generate huge distortion each time. Isolating components traced the problem to the Yamaha. It must be re-clocking the signal enough that the Grace has a problem with it. Using the 901 as a preamp I never ran into trouble. I would guess that it is possible to bypass the s-lock for such situations, but I skipped the manual and went for the hardware.
Next setup, after various experimental configurations (still preamp): yanked the DP-u50 and Mac. Fed the Sony S9000 straight to the DEQ via optical. Gorgeous! Image is precise, instrument placement is very stable, and dynamics are second to only one system that I have ever heard (Pipedreams with gazillion dollar amps and 4x18 subs). Attack and decay are incredibly fast. Analytical, but without harshness. I like!
Other listens: I did connect the Ti-book straight into the 902 via usb. Very nice, but since I lost the room correction, it was a step backward for me. Anybody know how to route itunes output through pro-grade eq software?
Current setup: I had planned on getting a remote, but the 902 was just too inviting to leave with the power gear at the front of the room, or the source gear at the back of the room. It now resides next to my chair, with a somewhat shorter AES cable as feed, and a longer RCA cable to the x-over. Now I have the volume KNOB within reach for either speakers or headphones. The rubber o-ring on the volume control makes it nice for one finger (or thumb) operation. btw the volume knob has a nice feel to it, with positive click detents. The range is HUGE. I don't need this kind of resolution, but better too fine than too course.
My only remaining issue is a mild ground loop buzz between the 902 and my crossover. I had it with the 901 as well. I run into this occasionally, and I will sort it out.
Bottom line: sweeeet!
I still want a 904 though. otoh, if we can talk Michael into a portable Grace, it would have priority
gerG