I have read those other threads about using two combos together, but I am not sure about the details. I have Hughes & Kettner Bassforce 100W combo and a Behringer 30W combo. I guess I will be using the H&K as the master, because it is simply the better amp. The H&K has an FX Loop Out as well as a Line Out. The Behringer also has an FX Loop In and Out and seperate instrument inputs (active and passive). 1. Which output should I use on the H&K? The FX Out or the Line Out? 2. Which input should I use on the Behringer? The instrument input gives me volume control, I guess. But it also goes through the preamp. Could this be bad? How do I control the volume if I use the FX In? If I use FX In, could the H&K overpower the small Behringer? 3. Will this whole thing be any louder than the H&K alone? The way I see it the H&K (master) preamp does the whole job for both combos. Thanks you very much in advance for going into every detail.