The other 4 jacks could be 3 mono and one stereo. That is 2 mono for the Send and Return, one mono for the Output Jack, and one stereo for the input Jack if you are planning to use a battery snap. Be careful with the wiring of the Insert In and Insert Out jacks because the ones I used the wiring was slightly different than the diagram in the instructions, although I’m not sure if the ones I used were Switchcraft.