I was looking for a similar big tube amp as what you are looking for. I was able to get a very good price on a demo pair of VTL MB750 ref's and had them in house for about 3 weeks. I also have VTL 7.5 pre , alas in my system I could not get them to boogie or come to life. My speakers are Vienna Mahlers which are below 3 ohms for most of the bass, however amps costing 20k should have dome a better job - I guess synergy is everything. BTW VTL's should work well with vandy's as they are consistent as far as impedance goes.
To cut a long story short, I tried out SS amps like Pass X350.5, JC-1's, Mac 501's, Bryston 7B-SST and ended up with cj prem 350. The cj prem 350 sounded closer to my old tube monoblocks in the upper mids and treble, are nice and controlled in the bass and dynamically and harmonically lust are fun to listen to. They are less then VTL 450's, so if SS can co-exist in your system try to demo them. I think you maybe suprised.
cheers
To cut a long story short, I tried out SS amps like Pass X350.5, JC-1's, Mac 501's, Bryston 7B-SST and ended up with cj prem 350. The cj prem 350 sounded closer to my old tube monoblocks in the upper mids and treble, are nice and controlled in the bass and dynamically and harmonically lust are fun to listen to. They are less then VTL 450's, so if SS can co-exist in your system try to demo them. I think you maybe suprised.
cheers