MIDI DIN to MIDI USB Host Converter
The old way of making an Arduino MIDI USB host to MIDI DIN converter consists of an Uno, a USB host shield, and a MIDI DIN shield.
This project uses an Adafruit Trinket M0 which has USB host capability. The USB Host Library for SAMD and a USB OTG to USB host cable or adapter is required.
[dsp-G1 synth]https://hackaday.io/project/161652-portable-midi-dsp-g1-synth