Learning Analog Synthesis through the MS20

ROBOTSPEAk is now offering a shorter synthesis class that will teach analog synthesis using the Korg MS 20 as learning device. Back in the hey day of the Korg MS 20, teachers used the manual as an in depth tool for not only learning the instrument (see educators version of the MS 20 pictured above), but for teaching the concepts of analog synthesis and the basics of modular patching. With the recent release of the MS 20 mini, we started up these one session classes with an emphasis on the power of the MS 20 as a tool to teach students Analog Synthesis. Owning an MS 20 is by no means a necessary prerequisite for this class as Kurt will lay out analog synthesis concepts in a way that is universal and applicable to whatever Synthesizer you use. MS 20 minis will be on hand for this class for students to interact with.

Instructor Kurt Larson




VCO [Voltage Controlled Oscillators]:

demonstration of the VCOs pitch range and tones they can produce.

The following waveforms will be demonstrated and possible uses will be explained:




pulse wave [2 settings]

pulse width variable control [VCO2]

Two additional modules are accessed via VCO controls.  these will be demonstrated and explained:

white noise - used for wind and percussion sounds

ring modulator - used for some metallic and distortion effects.

 demonstrate VCO modulation [pitch modulation]:

LFO modulation

Envelope 1 modulation

brief explanation of external modulation input 

demonstrate additional controls:

master tune



demonstrate complex tone shaping possible with 2 VCOs

brief discussion of external signal processing and how external signals are mixed into the ms20's signal flow.

VCF [Voltage Controlled Filters]:

demonstrate cutoff frequency for Low Pass filter

demonstrate cutoff frequency for High Pass filter

Resonance/Peak and how it affects both filters

brief explanation of harmonic series

demonstrate use of filters within context of harmonics

demonstrate Envelope 2 modulation

demonstrate LFO modulation

Brief description of External modulation of cutoff frequency

VCA [Voltage Controlled Amplifier]:

explain how EG2 controls VCA

briefly describe 'VCA2' on patch panel

EG1+2 [Envelope Generators]:

demonstrate time/level controls for both envelopes

demonstrate 'looping' trick for EG1

explain implementation of EG2-VCF hardwired patch

use MG, VCA2 and EG1 to create a 'delayed vibrato' effect.

MG [Modulation Generator or LFO]:

demonstrate frequency range of LFO

demonstrate variabe triangle waveshape

demonstrate variable duty cycle of pulse wave

Additional Modules:

briefly demonstrate Sample/Hold using LFO to clock noise for random effect.

explain unusual 'sample/drift' design of ms-20 S/H

revisit VCA2 and 'vibrato patch' above.  discuss use of VCA to control modulation.

Additional Controls:

demonstrate Control Wheel with VCO and/or VCF 

demonstrate Control Wheel used to lock VCA open.

briefly discuss other uses

demonstrate Momentary Button used to trigger synth

demonstrate Momentary Button used to control vibrato patch

briefly discuss other uses

ESP [External Signal Processor]:

demonstrate ESP controlling ms-20 pitch and envelopes.

demonstrate ESP being used to process drums or full mix.

Remaining class time will be spent doing patching experiments with the ms-20 synths.

Please call 415-554-1977 during business hours to sign up or email info@robotspeak.com with the following information:



Phone #

Best time to call for payment details to lock in your spot.

Space is limited!

Kurt Larson