Tube pre-amp upgrade from Mcintosh C2300

I've found C2300 is very responsive to tube rolling. So like Tls49 suggests, that would be a good first step. Still, every poster I've read who has moved to the C500T from the C2300 has reported substantial improvement. Most reports, though, specify using balanced outputs. If you're all SE, the improvement might not be so great, I don't know. In my system, RCA out sounds more liquid than XLR from the C2300.

You'll have to roll the C500T if you want the best out it. If you don't want to tube roll, and ARC and Shindo don't need it, audition those two brands, choose one, and be done. Sounds like you've pretty much answered your own question.