I used a carver TFM-45 amp with a CT-17 preamp for years, but recently went on an upgrade/revision binge. I started with a Denon receiver in hopes of simplifying things. I sold the Carver gear to pay for the Denon receiver. Very bad move. Sounded like crap compared to the Carver. Moved to an Adcom GFA 555 amp with Adcom GFP 750. Still not as good as the Carver. Moved to a Sunfire 300 watt/channel amp with a Bat VK-40 preamp. NOW we're talking! Swapped out the Sunfire in favor of a Bat VK-60 tube amp. Oh my!! Sounds great, but what a beast. Big, heavy, sucks power like there is no tomorrow (500watts!! at idle) and generates more heat than my furnace. Not really suitable for all day background music. VK-60 is currently in the garage with the Sunfire back in the system. I'm very happy with the sunfire and only miss the VK-60 on rare occasions during critical listening sessions.
Overall I don't plan to ever part with the Kef speakers. I may swap the VK-60 in (during the winter! ), but the Sunfire is an outstanding match with these speakers. I use the "current source" outputs of the amp and the balance inputs from the VK-40.
Anybody want to buy a nice VK-60?