Can't remember if I already posted but Roland Duo Capture Ex has been solid for me. Paid £60 on eBay. Takes batteries. Pretty small footprint + Midi i/o + stereo in/out or split inputs (I think) + phantom power (I think). The midi i/o has come in handy in a few setup variations. Worth considering for an 'all in one' thing to have laying around.
I wonder if this box could be my answer with the midi issues in getting OP-1 and something like Kordbot working properly? The midi capabilities on this is basically what a Kenton box offers right?
But iirc I had my op1 connected via a cheap usb>din midi cable and all good. Will check when get a minute. Though I might just be thinking about it wrong. It does receive midi via the USB, just not sure you can plug a USB synth in. And send to din midi out… If that’s what you’re looking for? Maybe someone else can clarify if it does what youre after.