Korg MS-20 Maintenance

Korg MS-20 PCB Internal

The Korg MS-20 is a staple of semi-modular synthesis, but its aging mechanical components often lead to signal degradation. This project involved a deep dive into the internal hardware to restore the tactile reliability and sonic clarity that these machines are known for.

Restoration Highlights

Over time, the semi-modular patch points and potentiometers on an MS-20 can accumulate oxidation, leading to scratchy audio and unreliable modulation routing. My service focuses on preserving original components wherever possible through advanced cleaning techniques.

Potentiometer Deep Cleaning

Instead of simple spray-cleaning, I perform a thorough chemical restoration of the specialized Korg potentiometers to ensure smooth, noise-free operation across the entire sweep.

Jack-Switch Replacement

The 3.5mm switching jacks are critical for the MS-20's normalled signal path. I replaced oxidized jacks to ensure that internal connections break and make reliably when patching.

Signal Path Audit

In addition to mechanical repairs, the unit underwent a full calibration of the dual VCF (Voltage Controlled Filter) sections. This ensures that the high-pass and low-pass filters respond accurately to control voltages and maintain the iconic MS-20 resonance characteristics.