if I wanted the svt sound in a small/DI package, id go with the guys that invented that sound, I think ampeg is seeing how well tech21 us doing copying their sound....
plus the ampeg scr has ultra hi and ultra low switches, something the tech21 pedals don't...
the VT pedals seem cool, but id rather go to the source IF I wanted that tone!!
the only thing that tech21 has on either the ampeg or Darkglass preamp/DI's is the VT deluxe, only for the fact that it has 4 channels(which I really dig!) but I much prefer the dark glass b7k over the ampeg sound
The darkglass pedals is different. they have tube-emulated distortion sounds. it doesn't have that beefy sound the ampeg scr and tech 21 vt bass provides. if you wanted something that has an svt type sound, you're better off with either the ampeg scr or the tech 21 vt bass.