Why not use both? My feeling the amp alone is probably fine as long as you don't get too heavy with the low end AND the volume.FightingPlankton wrote:you could always just get an extension cab and disconnect the internal speakers when switching to bass vi. probably significantly easier than modding the amp.
You do have a two channel amp to work with, so that could help compensate for volume/tone differences between VI and standard. Add an a/b box at the end of your effects chain and you could use the same pedals for both (run one side to Normal and the other to Vibrato). Or add a pedal (or preset if you already have something that would work) for specific volume/eq/compression tweaks just for the VI.