Hi there,the amp is a mono amp,all 4 outputs are in parallel.Back in the day it was common for speaker "columns" to be 16 ohms,and a lot of other cabs too,so you could run 4 cabs/columns off of the head which gives you a 4 ohm load.Also the main EQ is a cut only,you can't boost any freq.'s with it.Good luck,Mel.