Welcome to this tutorial on how to turn your Channel-Challenged Work Horse into a Multi-Channel Monster!
What you need is an amp with a serial effects loop and a distortion channel you like. You'll also need a multi-effects unit (preferably floor-based) also sporting a serial effects loop. Watch the video for examples of what I've used, a Egnater Rebel 30 head, and a (very) old BOSS ME-5.
Got your amp, FX Unit and the FOUR cables ready? Let's go!