Jc-120 Schematic May 2026

Inside the "King of Clean": A Look at the Roland JC-120 Schematic First introduced in 1975, the Roland JC-120 Jazz Chorus

8. If You Can’t Find the Exact Version

JC-120 went through revisions:

6. Where to Find High-Quality JC-120 Schematics

Do not trust blurry JPEGs from random forums. A pixelated schematic will lead to misreading a 100k resistor as a 10k, blowing your power transistors. jc-120 schematic

The schematic of a JC-120 typically reveals a complex signal path where the "Effect" channel splits the signal to achieve its iconic stereo field. 1. The Preamplifier Section Inside the "King of Clean": A Look at

Reverb: Generally a mono spring reverb tank, though some schematics show it could be modified for stereo-like separation. Check IC11 (MN3002) pin 7 (output) with scope

5. Common Repairs & Schematic Clues

Symptom: No chorus / weak chorus

• Check IC11 (MN3002) pin 7 (output) with scope.
• Verify clock at pin 6 of MN3101.
• Adjust VR5 (chorus level) and VR6 (BBD bias).

The most critical part of the JC-120 schematic isn't a single circuit, but the fact that it is actually two 60-watt amplifiers in one box True Stereo Output: