Hi George, I am not familiar with the VAC. If it is a push/pull configuration though, chances are that it will not sound the same as a true SET. All of the SET's that I have auditioned sound quite different from one another (everyone needs to audition them individually), but the better ones all do have one thing in common, which is a depth and 3D effect that I have never heard with push/pull tube designs. This is what it's really all about. The problem that I had was deciding whether to work with the lower SET power, or to make a compromise and go for something push/pull (though with fat sounding tubes, such as EL34's or 300B's) and make it easier on myself by adding the extra power. There are also some hybrid designs I believe that somehow switch to push/pull when more power is needed for musical peaks. Having owned quite a few push/pull tube amps in the past, I decided to go full SET to try something new. The amp was referred to as the "new toy" for many months until I was able to get the system properly matched, because that is what the amps will sound like until you get the right combination going. Other than speaker sensitivity and impedance there are other factors (just like in any system) to consider such as the output of you preamp (or source/DAC in my case), the cabling and how it interacts, the tubes used and the room size. My particular amp is somewhere between (sound wise) that of typical 2A3 and 300B amps in that it is quite linear and detailed and it has very fast transient response. The 300B tube, itself, can actually be linear, but how it will sound depends on the design of the amp. Many designs roll off the bottom and top and let distortion run wild and this sound is generally not to my liking, but on the other hand it (this type of sound) is favored by the majority of users. The epiphany for me was when I went to audition a well setup system consisting of AR 300 mono blocks, Vandersteen 5's and top of the line AR and BAT preamps. Sources were BAT and Oracle CD players and an Oracle turntable. This was a great sounding system, but as far as the reality factor of the music went, my little budget setup crushed this system (it was no contest). The little system did not have the bass or dynamics of the big rig, but I discovered at that point (or proved to myself) that there is a lot more involved in total sound reproduction than bigger than life dynamics and bass slam. The only "major" obstacle that I see with SET's is for people who have large listening rooms and who do not like the sound of or who cannot afford the more expensive (highly rated) horn systems that are available today. There seems to be a shortage of high quality and affordable speakers that will work in this type of application. I urge anyone interested in SET's and who is willing to do the work to start by auditioning as many of them as you can, but I do not suggest purchasing one blindly (without hearing it first) due to the diversity of their sound which is dependent on both the design of the amp itself and proper system matching.
