I run mine in from of either a Red Plate CD2 or a Two Rock 22pro. Amps clean all effects including dirt from the FX8.
It sounds great.
If you are interested I can send you links of lousy iPhone videos of my cover band so you get an idea of the variety of tones I get live.
I run mine in front of the amp too. I use a Twin Reverb and it sounds great.
DT