Amplifier for Vandersteen 5A' s ?

I recently had an opportunity to listen to the Vandy 5a's and was really impressed. I currently own the Pass X-600's and think they do a remarkable job with my Magnepans, but if I buy the Vandys I would like suggestions on other amps that mate well with the speakers. Tube or SS, and preferably mono's. The budget for the amps should not exceed $6500 used. Thank you much for your suggestions.
Should you purchase the speakers, why not first try them with the amp you have? That way as you audition other amps you have a baseline as a comparison.
I did that when I moved up from the 3A sigs. to the 5As. I kept the Dreadnaught amp that I had been using while trying others. I reluctantly let go of the SS Dreadnaught after using a ARC tube amp in my system. I really wanted the Dreadnaught to better the tubed amp for two reasons. One, I had bought into the idea that SS was better when it came to amps and didn't want to admit that I was wrong and, two, I didn't want to spend the money.
I'm sure that there are many amps that work well with the 5A's but, I know for sure that Audio Research amps match very well with them, assuming that they also match well with your pre amp.
Quicksilver V4, Atma-Sphere MA-1 mkII.3, Theta Enterprise...
Those are the only mono's in that price range that pop into my head right now.

I have the 5A's and I think the best bang for the buck that match that speaker perfect is the amp that Richard vandersteen and I use the Quicksilver v4. I had rca switched to balanced and think it is woth the upgrade. They are very low maintance take a varity of tubes and sound grate. Also 120 Whatts...

I have also herd the Cary on them the 308 siginature edition and think they sound a bit more open but they are of course twice the money.
You can add used VTL sig450 to the list.

I have 5As and have been looking around too. Unless you are in hurry your Pass W-600s should work well.

I called Richard Vandersteen a while ago. After he realized I was serious, I told him that I had Pass Aleph 2s and that I was considering Theta monos. To my surprise he called that largely a latteral move (though he said the Thetas were really good) and that I should consider tubes. He thought tubes had the advantage of better image body (I forget the exact term used) over the best solid state.

Our conversation was cut short so I hate to say too much with out a more extensive talk.

But Vandersteens are tube friendly designs if you want to deal with tubes.

FWIW I have on my list at this time Quicksilvers (max value), VTL sig450 (used), ARC VTM200 (use, more $) and if I really go wild ARC ref 210s or VAC Phi 220s(if I can find a deal). If I stay solid state the Theta monos. Still looking, got a few months yet.
Several 'goners use SMc modified McCormack DNA amps with the Vandy 5's with excellent results. I believe Steve uses Vandersteen speakers to voice his amp mods, although I'm not positive about that. There is some serious synergistic mojo happnin' with those amps and speakers. The dealer that sold me the Vandy 5's also sells ARC and he agreed that the moded DNA-225 outperformed a freshly retubed VT100MkII amp with those speakers. I think you'll hear from others here about their experience with Vandy & McCormack mods. The Quicksilver tubed amps also get high marks with the 5's, but I suggest you follow Agaffer's advice and try your Pass amp before considering changing amps.
The top two choices have to be a pair of Quicksilver V-4 Monoblocks or a stereo/mono pair of BEL 1001 Mk Vs. The BELs will outperform the V-4s. Try them and see!
Thank you for all the suggestions. I fully intended on trying the Pass amps first, however those 5's really don't need the power the pass amps have and in the process I could pocket a little change. I did consider the Mccormack. I used to own the DNA-2 Anniversary edition w/ an SMC gold revision. It was probably my favorite SS amp I've owned. I'm still calling myself a moron for selling it. I really need mono's, so the DNA-2 is out. I'm still looking forward to hearing from more members. Thank you again
I'm using an Ayre V1xe with terrific results. I understand the monoblox are also good..
You should consider the Sanders ESL Monos, terrific sound. I just auditioned the Quattros with this amp, and it far outperforms anything I've heard out there. The imaging is first rate and the detail retrieval is nothing short of amazing.

The rest of the system comprised :
Accuphase TPT, Benchmark DAC1, Slinkylinks ICs, ModWright Pre, Sanders ESL Monoblocks, and the Quattros.
Richard was at the NYC show this past week and his 5A was powered with Accoustic Research with great results. I think your current amps are atleast worth a lengthy trial.
My dad is running Classe monoblocked amps with his wood Quatro and they sound close you have a very high class dillema on your hands, lucky man!
A friend of mine uses Parasound JC-1 monoblocks and they sound fabulous with the 5As.