Korg M1 Serial Number Page

Unlike modern synths with complex date codes (YMDD), the M1 uses a relatively simple, albeit inconsistent, system. There are three distinct eras.

| Serial Range (Approx.) | Likely Production Year | Notes | |------------------------|------------------------|-------| | 100000 – 150000 | 1988 – 1989 | Early units; still use original factory presets. | | 150001 – 210000 | 1990 – 1992 | Peak production years. | | 210001 – 260000 | 1993 – 1995 | Later units; may have updated ROM or minor hardware revisions. |

Important: Korg sometimes reused number blocks for different markets, so these ranges are estimated guidelines, not absolute rules. Korg M1 Serial Number

Early M1s had:

Later serial numbers (210k+) tend to have more reliable power supplies and backlights. Unlike modern synths with complex date codes (YMDD),

If you are buying or selling a Korg M1, the serial number can swing the price by $100-$300. Here is why.

Beyond historical curiosity, the M1’s serial number has concrete, practical uses for owners. Important: Korg sometimes reused number blocks for different

1. Hardware Revisions and the "M1 Problem" : Early M1s (serial numbers below approximately 50,000) are notorious for two specific age-related failures. First, the internal CR2032 battery that preserves patch memory—when it dies, the M1 becomes a preset-only brick until replaced. Second, and more critically, the power supply capacitors on the main board of early units are prone to leaking or failing, causing hum, noise, or complete failure. Knowing your serial number is low (e.g., 12xxx) tells you to proactively replace those capacitors. Later units (serial numbers above 150,000) have revised power supplies and are generally more reliable.

2. Operating System Version: The M1’s OS was updated several times. The earliest units had OS version 1.0, which lacked some MIDI implementation features and had minor voice allocation bugs. Later units shipped with OS 1.14 or 1.20. While the OS can be updated via EPROM chip replacement, the serial number gives a strong indication of what OS the synth left the factory with. A high serial number (3xxxxx) almost certainly has the final, most stable OS.

3. Authenticity and Theft Recovery: The M1’s enduring popularity has led to a small but real market for counterfeit parts and "franken-synths"—units assembled from the broken shells of multiple M1s. A missing, damaged, or mismatched serial number sticker (e.g., the sticker says "Made in Japan" but the serial format is Italian) is a major red flag. Moreover, if you are buying a used M1, always record the serial number. If the instrument is ever stolen, that number is your only proof of ownership.