The Korg monotribe is a desktop analog monophonic synthesizer with an additional three preset drums sounds. Its sound is warm and rich but quite clicky and noisy – although I think I prefer this timbre over the newer volca series. The monotribe was released in 2011 and is now discontinued.
How to Silent the VCO When Processing External Audio
The synth has an audio in port to feed external audio into 12 dB/oct lowpass filter (which uses the same circuit as the classic MS-10/MS-20). The crux is that the synth engine must be triggered to run the filter, meaning it’s not possible to process external audio solo (without being modded). But the LFO can modulate the oscillator so that it becomes nearly inaudible. The workaround below is not exactly neat, but should do the trick. On the monotribe, do as follows:
- Press PLAY button and then REC.
- Set RANGE select switch to WIDE and press the highest key on the RIBBON keyboard during the whole sequence.
- Set EG to GATE.
- Switch TARGET to VCO.
- Set MODE to 1SHOT.
- Set WAVE to SQUARE WAVE.
- Set LFO RATE knob to minimum speed and INT. to maximum depth.
- Select TRIANGLE WAVE on modulation waveform WAVE.
How to CV Control the monotribe with the Analog Keys’ Keyboard
OS version 2.11 allows the SYNC IN connection to be used as a pitch CV/gate input. This makes it possible to control the monotribe with an external keyboard or sequencer (which is great because the ribbon keyboard is almost impossible to play). There are many ways to do this, but the theory is the same: send CV and gate via a TRRS 4-pole mini jack – where gate is tip and CV the second ring.
Now I got an Elektron Analog Keys which can send both tip and ring from the same CV output, but to do that to the monotribe I’d need a special cable (sort of TRS to TRRS) and I haven’t soldered any yet. So until then, I hacked a workable cable with many different pieces I found laying around (e.g. the composite video cable was provided with a TV I acquired last year). Again, you can build this patch cable more streamlined, but here’s my solution:
- Connect a composite video cable to SYNC IN on the monotribe and connect a RCA connector, white male to white female and red male to yellow female. On the other end, connect a pair of adaptors, RCA female to mono 3.5 mm mini jack male and then another pair of adaptors, 3.5 mm mini jack female to 6.3 mm jack male and plug white in CV AB and red/yellow in CV CD on Analog Keys.
- While this setup only uses the tips, and demands both CV ports on Analog Keys, set CV A to Gate, V-Trig, 5.0 V and CV C to Pitch V/oct, C 3, 1.000 V, C 6, 4.000 V. (CV B and D are not used.)
- Download and install System Updater 2.11.
- Prepare the monotribe as described in the documentation that came with the download package. Activate CV/GATE mode, set the Pitch CV curve to V/oct and GATE polarity to high.
P.S. It’s also possible to create a feedback loop by feeding the headphone output back into the monotribe’s audio in. This will render a mild thickening, and if you have some kind of attenuator on the feedback signal path, you can dial in some overdrive too.