I want to use my Sansamp pedal as a preamp, and use my GK 400RBIII as the poweramp. I've heard of people plugging the pedal straight into the effect return of the head, therefore bypassing the preamp on the GK. I tried this once, and it was much much louder than just plugging my bass into the head with the gain at about 10 I believe. I want to do this at gigging volume, but I don't want to blow anything up. My question is, if you have run with this setup before, what volume levels did you use on the pedal (and head) to achieve the best results?