Korg M1 Serial Number Guide

Debatable. Higher serial numbers (1991/1992) have better output jacks and more reliable tact switches under the buttons. Lower serial numbers (1988) have a thicker, heavier build quality and more "vintage" character in the keybed action. Neither sounds different.

During the COVID-19 pandemic, a hobbyist named Electropict started compiling information on early Korg serial numbers. This project grew into a webpage with approximately two thousand serial number entries , of which about eighteen hundred are sourced from MATRIXSYNTH references. Korg M1 Serial Number

The peak of production. These units usually feature the most stable firmware (Version 1.9 or higher). Debatable

The first batches of the M1 occasionally faced minor issues with the internal power supply heat sinking or the tactile feel of the buttons. The M1R and M1EX: Neither sounds different

Serial numbers from 150000 up to 250000+ . These later units often shipped with the final stable firmware versions and have experienced less overall component aging. Why the Serial Number Matters to Buyers and Collectors

If you encounter a Korg M1 with a missing or scratched-off serial number sticker, you can still estimate its hardware generation through a few physical clues:

The sticker almost always begins with the model identifier “M1” followed by the number. However, there are important variations for different models in the M1 family: