Steve's suggestion of following the schematic worked! Here's how to add an effects loop to a Kustom Kombo organ...The place to tap into the audio output is at the expression pedal. There is a thin single wire (mine is red) going from the expression pedal to the amp. Simply cut the wire and add either a female 1/4" to each wire or, alternatively, a guitar cable, to each end with the ground attaching to the chassis. I don't use the accessory preamp so I'm going to use the holes where the input jacks are now with 1/4 " female jacks going to the loop circuit. This will be a convenient place to plug in the effects without making any new holes. The old jacks will simply be unscrewed and tie wrapped behind the preamp panel. If you don't want to use the loop, remember to jump the jacks with a short cable. I just tried the loop with a digital delay and it's awesome. I can only imagine how this will sound with a Leslie simulator ( I see a Neo Vent in my future) pumping through those JBLs! Kudos to Steve for pointing me in the right direction!