Recommendations for a new integrated amp for Vandersteen 3a speakers

I’ve used Belles amps with Vandy 1s through quatros, including 3a sigs and think they are a great match as others have stated. I have not heard the aria integrated but have read it is special with Vandersteens. They show up used in your price range. Belles are not flashy, but they sound right. I’ve also tried a number of preamps and they make a huge difference to the sound. I have not heard your adcom, but imagine a newer high quality integrated would outperform an amp mated with your preamp. Ayre and Aesthetix are the other matches you’ve likely read about, but they will be at a higher price point than you are targeting.

I've owned 2 of the integrateds you are looking at.  First was the Vincent.  I liked it but it had problems with the tubes.  German design, chinese build.  Sound was very pleasing.  Laid back presentation.  The music traveled to you it didn't attack. Had tone controls which is rare. So after that I traded to the MF 6si....not 6i.  Overall I like the MF better.  This thing is a beast and will handle anything you throw at it.  As you raise the volume you feel it building power without loss off nuance.  You can play a great classical piece and let flow and right after that smack on some hard rock and it will give you the meat and potatoes without sacrificing detail.  Lastly, I've heard the rogue as well that is a fine choice too.  good luck.

...sell the preamp - go integrated or a power amp that you can play directly. Save money on interconnects - and simply your system...

Try a Schiit Vidar: class AB, 100wpc/8ohms, 200wpc/4ohms. $699.

One reason the Belles matches up well with Vandersteens is because of the complementary “voicing” of the amp and speakers. It’s one key to any system’s success. Obviously this “match” is well known and well regarded in audio circles and should be at the top of your list. Used Arias go for around $1500 so be patient and pick one up when available. Good luck!