any body here use the valve junior with a multi-fx?

does the amp color the tone too much for multi-fx?

I basically need just the power-amp stage of it because the gnx3k is my preamp,
is there a mod to pass the pre-amp stage of the VJ?

Ibanez S370 (all custom)
Mesa Boogie Studio Pre
Fender Champ 25se (used to power Mesa pre)
Custom 2x12 cab w/ Eminence Texas Heats