Roland & Korg Service

Japanese Analog Synthesizer Internals

Japanese synthesizer design from the late 70s and 80s combined innovative proprietary integrated circuits with robust mechanical engineering. However, these instruments now face unique "age-related" illnesses—from leaking VCA chips to corrosive battery damage. My workshop is equipped to handle these delicate precision repairs using period-correct components and modern diagnostic techniques.

Roland Restoration

The "Roland Sound" relies heavily on custom IR3109 filters and BA662 VCAs. I provide specialized care for the entire vintage line, including the Juno, Jupiter, and TR series:

  • Juno-106 Voice Restoration: Expert chemical stripping and restoration of the 80017A VCA/VCF modules to permanently fix "hanging notes" and crackling.
  • Jupiter-8/6 Calibration: Deep-level tuning of the discrete voice boards to ensure perfect polyphonic tracking.
  • Power System Recapping: Comprehensive replacement of aging capacitors in internal power supplies to prevent hum and rail instability.

Korg Analog Maintenance

From the MS-20 to the Polysix and Mono/Poly, Korg's analog era produced some of the most aggressive and beloved filters in history. My service addresses their most common failure points:

  • Polysix Battery Damage Repair: Precision trace reconstruction and neutralization of alkaline damage on the KLM-366 programmer board.
  • MS-series Slider & Jack Service: Deep cleaning or replacement of "scratchy" potentiometers and oxidized switching jacks to restore signal integrity.
  • SSM/KORG IC Diagnostics: Identification and replacement of failing proprietary chips using verified NOS (New Old Stock) or modern boutique clones.

Precision Alignment

After any electronic repair, I perform a full factory alignment. This involves using an oscilloscope and high-precision frequency counter to set VCF resonance, DCO scaling, and VCA offsets to the exact millivolt specifications found in the original service manuals.