[GtiGyver]

This thread was a godsend.
Thank you.

Just finished upgrading my 2008 E90 M3's Logic7 sound system to the Dirac individual audio system.
I can confirm that this works even if you don't have iDrive with one caviat. It seems I lost the ability to enable any kind of surround sound mode, I do have the choice of Music and Cinema modes on the OEM head unit but they have no effect.

Regardless of this, the sound seems better/fuller than the Logic7 system as far as I can tell. I only just tested it for 10 minutes.

Also, the OP is correct. The AMP worked with the original VO $677 just as well as $752. There were no audible differences or functional differences I was able to dicern.