[quote name='mazdah' timestamp='1423177347' post='2681999']
You certainly can! But LB-30 (mine, not sure about newer ones) has effects loop BEFORE preamp, not between preamp and poweramp, so both preamps will work in conjunction, no matter how you plug it in.
[/quote]
Really? What would be the point of having it before the preamp? That wouldn't be a "loop" at all - it's no different to plugging into the front of the amp!