Preramp for Adcom GFA 565's

That's the combo I had about 17 years ago, running into Martin Logan Aerius speakers. It was pretty good. If you are looking for another option and products based on the same time frame, you could also consider a Melos preamp (SHA 1 or Gold). These are really nice preamps for the price you can get them for and make wonderful headphone amps to boot. I think the Adcom/Adcom combo can get a little bit brite (depending on your speakers). But overall, I think that (Noble100s) approach is worth trying for you.

The VTL is a good recommendation. Other tube preamps that you should be able to get for a good price (and with good reputations for performance) that you might also consider would be any of the following:
ARC (Audio Research) LS7 (and others I am sure, but I once owned the LS7 and as a result I know that would work well).
Golden Tube audio SEP 1 (I think that's the model number. I never owned one, but did own a couple of their amps SE-40s running in mono. Good equipment).
Sonic Frontiers Line 1,2, or 3 (depending on budget)