DAN.2000 ... Imagine 4 Water pipelines going into 1 Main pipeline and that Main pipeline has a valve on it. When you open and close that Main valve you control the water for ALL the pipelines!! With me so far? NOW if you Seperate 1 of the 4 Pipelines and put a valve on IT, THEN, the Main valve will not control the water from that seperated pipeline any more! And, consequently, the valve on the seperated pipeline will control the water from it. It is the same electricly (did I spell that correctly?) ALSO when you send the Bass Drum to a seperate out on the SD1 I found that some Drum sets do not function properly. The Drum set does not sound correct. I do not remember the Styles with this problem but you will hear it when you use one. I do not have an explaination for this. I hope I helped.