This option provides 2 additional amplifier channels and a separate enclosure with input jacks, output jacks, and level controls. These channels may be used to play other keyboard instruments, rhythm units, etc. through their own amplification system, but under the control of the organ swell pedal. In addition, either input can be routed through the organ sound system by moving a jumper on the SSP-3A circuit board. When configured this way, the AUX-1 input will be expressed, and the AUX-2 input will be un-expressed.