Quick rundown of SP404MKII and MC707
using the SP404MKII as a Send and Return effect on the MC707
using the SP404MKII as a MIDI Controller
applying Delay send to an individual instrument on a Drum Track

What's needed:
SP404MKII
MC707
4x TS cables
3.5mm to MIDI DIN cable

How to:
MC707 Send SP404MKII Input
SP404MKII Output MC707 Return

Setting up the MC707 :
Shift + Input Send, MixOut Return, MixOut
Shift + Knob Assign System MIDI Auto Channel = [1]

Setting up SP404MKII:
Shift + Pad [13] System MIDI MIDI Sync Out = ON
EXT SOURCE needs to be on to use MFX