Harder to get the Mesa amp to break up than an SVT.I would replace SVT by being more specific: the rackmount Ampeg stuff. I suppose it's branded "SVT" as well, but you know what I mean. I don't recall seeing too many Mesa 400s around. Seems like the road ready Mesa cabs were 10x more common than the amps were. A lot of guys used the GK 800rb with Mesa, Hartke, or Ampeg cabs.