I had the earlier version of this preamp av7701 so I knew very much what to expect and have been very pleased with this new version even if its not the lastest Marantz. Naturally there is a figuring out, making adjustments period with any new piece of equipment, but it has been fun, not torturous. The sound is as I hoped for richer, great detail. I could never get the old device to connect to my new computer, windows would not recognize it as sound device. During setup the 7706 was immediately recognized. I like the phone app with one caveat - it is difficult to adjust volume on the app. The slide bar is very small so is the positional indicator. I also found the Audyssey settings not to be what I wanted at all. That was easily correctable. All in all I find the 7706 an improvement and as objectively as I can be great sounding device.
I packed the old av 7701 in the shipping box that you sent the new one in. If you guys would like to refurbish it or know someone who would, I'd like to send it on. The problems it has are control issues not sound quality issues.
Thanks Bill Wears