So, the bass goes into a Roland GI20, which provides MIDI notes and audio. Audio goes into an Eden WTDI preamp and then into any decent audio interface. MIDI goes via USB into the computer – which only works on Linux because the G20 needs special drivers and other OSses do not ship them included, and it's and old device… difficult.
I can control parameters (such as volume of the FX returns) via an AKAI LPD8 MIDI controller.
Yet, there's trouble which I often have with this kind of setup: None of the delay plugins I have has a tap control that can be operated via MIDI. Jack/Carla can be sync'ed to MIDI clock, but that doesn't help either with the buttons of the MIDI controller.
Also, my elderly studio PC is a little challenged at 256 samples buffer size (RME Digi PCI sound card… also only Linux drivers available these days).