For a while, I assumed that the VST Amp effect used different algorithms from Cubase’s VST Amp Rack, because the amps didn’t sound as distorted.
It turns out that the knob behavior is misleading. See video:
The drive knob is set to 10, but when you switch amps, that setting isn’t actually applied until you move the knob again. The same goes to all of the tone knobs (bass, treble…).
This can lead to a lot of confusion since each amp uses the last used settings, but the knobs don’t reflect that at all. If you’re experimenting with different amps, it’s very hard to keep track of what settings are actually being used without moving all of the 5 knobs.