Boss VF-1 Effect Processor

Hi Bert:

It's true that there's only 3 intensity levels in the VF-1 but each
level can be adjust from 0 - 100 of gain... you only need to set one
of those 3 intensity levels of overdrive and saturate or desaturate
them with the volume parameter of the pre-amp that you choose... (the
volume is the second parameter of the preamp algorithm).

I hope you can get the sound that you like

greetings

Martin