https://www.modemachines.com/professor-v2
Discontinued years ago, but I picked one up on Ebay Australia from a reputable company new for £250 inc postage.
Spoke to the tech support guys at Mode Machines who were really helpful and told me:
There is one left in stock if anyone else wants one. I will report back here to confirm it is working well with Repro-5.I'm not sure it will work with the repro-5 but it probably should.
The Professor V2 is a class-compliant USB-MIDI device which SHOULD work out of the box without any drivers with practically every USB host. The USB-MIDI engine inside is a Ploytec GM5 IC: https://www.usb-audio.com/gm5/
(They claim compatibility with Linux and so far I haven't heard anything contrary.)