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 features two independent channels. Channel 1 is a standard "Normal" channel, while Channel 2 includes the effects (Distortion, Reverb, and Chorus/Vibrato). The schematic shows high-impedance FET inputs followed by multiple gain stages using discrete transistors or op-amps (depending on the production year). jc-120 schematic
JC-120 UT / JT (2nd Edition - these are the newest JC-120 amps) - Gain stages are discrete, FETs or combinations of FETs and BJTs. Solid State Guitar Amp Forum JC-120 | Jazz Chorus Guitar Amplifier - Roland For four decades, the Roland JC-120 (Jazz Chorus)