I'm using a Musical Fidelity Nuvista M3 with the VSM mmi. The sound is very good, but then I don't have a lot to compare it with. I have a pair of atma-sphere M60s but I don't have a pre-amp to go with it yet. I have tried taking the pre-out from the M3 into the M60s. The M60s clearly work better with the VSM's then the power amp in the M3 does, but for the most part it isn't a huge difference. That could also be because that pre isn't the best match with the M60s either. Biggest difference is in the bass which is fuller with the M60s then the M3. That surprised me because I always thought bass was the more the forte of ss vs tube amps and the M3 really does a great job with dynaudio speaker. I think it has to do with the higher damping factor of the M3 vs M60s which doesn't agree as well with the merlins.