BSIAB II in Effects Loop

[modsquad]

So I was messing around with using my Digitech GSP2101 for the preamp and time effects.   So I put a BSIAB and a 7-band eq in the effects loop.   Turned on the effects loop in the patch on the 2101.   What I got was no effect from the BSIAB or EQ.   Replaced the BSIAB with the Danelectro "Univibe" clone (forgot the name).   It seems to work fine.    Could the problem be the level of output from the effects loop is not enough to drive the BSIAB?

FYI, the way the 2101 effects loop works is:

Guiter ----> Comp -----> Preamp ---->EQ -----> FX Out ------> [external effects] --------> FX Return ------> Digital Effects -----> Amp

I was reading somewhere that the line level of the signal from the FX out could be an issue.   I would really like to use Wah, OD, Distortion effects in the loop and time effects from the processor.