Korg KPR-77 MIDI Interface
The Korg KPR-77 is a neat little analogue drum machine from 1983. Sound-wise it shares a lot in common with its predecessor, the KR-55. Although intended as somewhat of a budget offering, Korg helpfully included slider controls for each voice level, much like on the Roland TR-707, as well as a dedicated output for the snare / claps. It has got DIN sync on it, but as it runs at twice the PPQN as Roland’s implementation, you have to set the clock pre-scaler on it to 32nd notes for it to play in step when synching it to other gear.
This self-install kit adds MIDI support to it. Firstly, it allows you to trigger all of the KPR-77’s drum voices from MIDI notes, including the two previously user-inaccessible metronome voices. Unlike with the machine's own sequencer, when played from MIDI notes there is no restriction on polyphony - all of the voices can be played at the same time. The MIDI note velocity can also be used to control the accent on individual notes. Additionally, with this new Rev. 3 version of the kit, the KPR-77 can also be synchronized to MIDI clock – just move the SYNC switch on the back to the IN position.
The MIDI board installs neatly in the machine’s battery compartment (note that as it installs here, you do lose the ability to run from battery power). The KPR-77’s existing SYNC socket now also doubles as the MIDI input, although the original DIN sync functionality is unaffected.
There’s also a push button which is used to ‘learn’ the MIDI channel. Simply hold the button down and trigger a MIDI note on the channel you want the KPR-77 to receive on. The note’s velocity will also be taken as the accent threshold velocity.