MIDI Guitar can only convert one audio channel to MIDI, but it has a VST version, so I can load 8 instances of it into a DAW like Mainstage and send each one it’s own string. I did a test run by sending my pedal steel to the 5.1 DiatonicShifters algorithm and routing each note of a 7 chord to a different instance of MIDI Guitar https://www.youtube.com/watch?v=IPAsXy2YPOU

For the dimensions, the main concern is height. Ideally I would like to fit the new pickup between the neck and the strings, which is only 13mm. For that I wouldn’t want the pickup to be taller than 10mm. I sent an email to Cycfi to see if that’s possible with some customization of the hardware but I’m not optimistic. My MSA pedal steel does feature a quick change pickup so it’s possible I could get a setup where I remove my normal pickup and slide in the MIDI one, but that would definitely be a downgrade in convenience. If a GK-3B approach could fit under the strings and still output a signal good enough for MIDI Guitar, I’d pick that for sure.

Although for now I am only planning to use MIDI at home, I’m only interested in investing if I know I could later use it at gigs as well. My H9000 lives with an ASP880 in a 3U gig bag which features a decently sized side pocket. The plan (assuming I am taking good advantage of MIDI and want to take it on the road) is to have the H9000 do the A/D conversion, send it to a mac mini that lives in the pocket, then get back a final mono synth signal. I’m open to any approach, but any additional devices need to fit in that side pocket alongside a small computer, and any other MIDI conversion software/hardware needs to support separate string pitch bends (key for pedal steel). Note that I don’t want to use the ASP880 for this project because I am already using the inputs at home for jam sessions.

Your thoughts are much appreciated, I’ve already learned a lot, and am curious if you have any more ideas. The eletro-pedal steel is very cool, curious to see how it develops.