What the VFETs have going for them is two things.
The first is that its possible using them to design an amplifier that will make the lower ordered harmonics (2nd or 3rd) as the primary distortion component, in enough amplitude to mask the higher orders. This results in a smooth sound and might be an order of magnitude lower than a tube amp of the same power (and lower output impedance too).
The 2nd advantage is that of soft clipping, but this is somewhat ameliorated by the fact that nearly all the designs *manufactured* employ feedback, and when you do that soft clipping isn't a thing so much.
You can build other kinds of amps that can get the same distortion signature. One key element is to insure that whatever the distortion signature is, its consistent at 100Hz, 1KHz and 10KHz. Some of the VFET designs seem to do this (so do zero feedback designs regardless of tube, traditional solid state or class D, so long as the bandwidth is wide enough).
It is nice when you get get an amp to perform that way as the improvement is easily heard and the system sound is all about the music- you can forget about the system making it.
The first is that its possible using them to design an amplifier that will make the lower ordered harmonics (2nd or 3rd) as the primary distortion component, in enough amplitude to mask the higher orders. This results in a smooth sound and might be an order of magnitude lower than a tube amp of the same power (and lower output impedance too).
The 2nd advantage is that of soft clipping, but this is somewhat ameliorated by the fact that nearly all the designs *manufactured* employ feedback, and when you do that soft clipping isn't a thing so much.
You can build other kinds of amps that can get the same distortion signature. One key element is to insure that whatever the distortion signature is, its consistent at 100Hz, 1KHz and 10KHz. Some of the VFET designs seem to do this (so do zero feedback designs regardless of tube, traditional solid state or class D, so long as the bandwidth is wide enough).
It is nice when you get get an amp to perform that way as the improvement is easily heard and the system sound is all about the music- you can forget about the system making it.