Amp upgrade suggestions for a $2K budget

While you can certainly make some marginal improvement with you amp/preamps, nothing will make close to as much difference as changing your speakers. I would find the speaker you most love for $2,000 and keep your electronics for a while. When you find the speaker you love, then I would tweak it a bit with the amp/preamps - it all mostly depends on the recording, the speaker, and the room. Which doesn't mean I would not recommend the VAC Avatar, it is a very good integrated amp, but if you really want a significant change for the better, start with the speakers - my 2cents.

Sorry Herbet, I did not mean to suggest that they are the weak link, you may love them and are the speakers you want to build a system around - if that is the case, then looking at your pre/amp makes sense. What I am saying is that if you are looking to make a change, changing speakers will make a much bigger difference (for better or worse) than making changes in your electronics, assuming you already have enough power and current to drive your speakers, which I think you do. So, I'm not commenting on the quality of your speakers at all, I'm simply suggesting that speakers (and your room) are far more important than any changes you can make with the pre/amp. If you love your speakers, the VAC Avatar is certainly one of the finest integrated tube amps you can find, made by a great company, providing great service and support.