RH 100 and a lead boot pedal?

Hello all. I have a question around using a lead boost pedal and a RH 100 head. I have a Seymour Duncan SFX-01 boost pedal and when I put it in line with my other pedals in the front of the head it does not boost, when I put it in the effects loop in the back of the amp it boosts WAY too much. (even turned all the way down. I know that the pedal is fine because it works great with my Peavey equipment, and I know that the head in OK because my other guitar had the same head (but a G2) and it does the same thing. So, what am I doing wrong? Or is there a limiter in the front of the head that will not allow too much input? The last thing that I want to mention, it will work on the front on the clean channel. Again, any ideas? Thanks in advance.

Where are you putting the pedal in your chain? Try putting it toward the begining of your chain. If that doesn't work, put it at the end of your chain to find out where you can get the boost.
I forgot to ask but does that amp have an fx loop level adjustment?
I don know that particular amp.