I have Vandersteen model 3's (not 3a sigs)and ran them with a naim supernait 2, and after a long time of messing with placement I got them to sound fantastic. Naim does have a "gainy" lively sound which I believe woke up the Model 3's to a point. Curiosity got to me and I purchased a pair of brand new model 2 signature 3's, to try. Still have the 2's(almost a year) but the naim is gone. The model 2 sig 3's are more refined in the mids and highs than the 3's with very slightly less but better bass. The naim was too much for the 2's in my setup. I now use an audio research integrated(dsi200) and it sounds fantastic. I believe its largely bc of the passive preamp. I have great results with the model 2 sig 3's but im under the impression right now that the integrated should have a passive preamp to compliment the time aligned design of vandersteen.(at least it worked for me) Really smoothened out the sound in a big way. All other integrateds I tried were active pre's and sounded similar to each other and missing something. probably due to room size? I tried an Ayre ax7 which was good(passive pre)but lacked power for louder volumes. In looking for a "powerful" passive amp, I ended up with the ARC. The passive pre is very engaging even at a low volume. That's my outcome after many amps with these speakers...so far lol. Hope it helps you!
Amps I "tried" with Vandersteen
Naim Supernait 2
Supernait 2 with high cap
Mcintosh ma 6900
Krell 400xi
Krell Vanguard
Musical Fidelity A308
Ayre Ax7
Audio Research dsi200
Amps I "tried" with Vandersteen
Naim Supernait 2
Supernait 2 with high cap
Mcintosh ma 6900
Krell 400xi
Krell Vanguard
Musical Fidelity A308
Ayre Ax7
Audio Research dsi200