As you can read in the descriptions, you will have to use the "controller" between mixer and amp. It's obligatory and comes with the 802s. Maybe you could use any other equalizer, because the so called "controller" is nothing else but a fixed equalizer, boosting frequencies around 100 Hz and 15 kHz. However as I stated before, even the "901"-controller sounds a little different. So the original one is to be preferred.