I play in a fusion trio - guitar, keyboard, and drums. I am the guitarist. One of the biggest problems with not having a dedicated bass player is what to do when the keyboardist solos. Originally, I used a Boss octave pedal to play bass lines while the keyboardist improvised. That eventually became a Parker MIDI Fly with the MIDI sent to an Alesis Nano Synth. Then I discovered how badass an analog synth sounds for bass and I got a Moog Slim Phatty. However, as good as the sounds were, getting stuck MIDI notes and not having a free right hand to adjust sounds was a problem. Now I have this beast.
The 2 ADDAC foot controller pedals control the volume of 2 voices - each plugged into a separate channel on the Doepfer A-135-1. The first channel is for the low 2 strings on the guitar for when I want play a bass line and guitar chords simultaneously. The other for the top 4 strings for when I need more complicated bass lines or lead.
Each of my 2 voices is a combination of 3 sound sources. The Moog Mother 32s handle the big deep beefy square wave bottom end. The Roland 512 and the Mutable Instruments Rings add a percussive organ type sound 1 octave higher on top of the bass to give each note some clarity and character.
I have Yarns configured in 2M (2 channel mono) mode - so it outputs 2 separate V/Oct and gate signals. The MIDI coming into the Yarns originates from a Fishman Triple Play MIDI pickup on my guitar - the dongle for which is plugged into a tablet running MIDI Routing software that sends the right notes to the right channels.
I'm just now starting to explore all of the other options this rack gives me, because of the 3 sequencers and multiple clock sources. I'm having a ton of fun with this, and my live rig has never sounded better or more responsive. I firmly believe that every MIDI guitarist needs to look into modular rather than the typical sound modules most guitarists use.