Jc-120 Schematic -

For four decades, the Roland JC-120 (Jazz Chorus) has reigned as the benchmark for solid-state clean tone. From its shimmering built-in stereo chorus to its legendary pitch-black noise floor, the amp has graced the stages of everyone from The Cure to Metallica. But unlike its tube-driven counterparts, the JC-120 is a complex beast of op-amps, transistors, and BBD (Bucket Brigade Device) chips.

The JC-120 is a 120-watt, two-channel guitar amplifier head designed by Marshall Amplification. Introduced in the late 1980s, it quickly gained popularity among guitarists for its versatility, reliability, and rich tone. The JC-120 is part of Marshall's JCM800 series, which revolutionized the amplifier market with its master volume control and versatile channel switching. jc-120 schematic

⚠️ Avoid scam “instant download” sites. Stick to known DIY repair forums (Freestompboxes.org, GroupDIY, MusicElectronicsForum). For four decades, the Roland JC-120 (Jazz Chorus)

A key feature in the schematic is the power supply voltage. The JC-120 runs on relatively high rails (often +/- 40V to 50V). This high headroom is why the amp stays clean at high volumes. Lesser solid-state amps clip the power supply early, causing "fizz." The JC-120 has enough voltage reserve to reproduce transients cleanly, giving it the punch and dynamics associated with tube amps. The JC-120 is a 120-watt, two-channel guitar amplifier

Roland JC-120 Go to product viewer dialog for this item. has been in production since 1975, and its internal circuitry has changed significantly over the decades. To find the correct "piece" or component for your repair, you first need to identify which version you have. Identifying Your Version

Roland historically provided service notes. The most reliable free sources: