@robshaw I can verify the good synergy between a Coda amp (the S12.5 in my case) and a tube preamp (Herron Audio VTSP - 3A).
I knew that I had a good amp; but, I didn't realize just how good it was until I swapped in a different power cable (Zavfino Silver Dart). So, don't be afraid to experiment with some different power cables with that amp.