When the chorus is engaged, the schematic shows that the effect circuitry routes the dry signal to one power amp (and subsequently one set of speakers) and the wet, chorused signal
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 jc-120 schematic
The JC-120's primary innovation is its power section. While most guitar amps are mono, the When the chorus is engaged, the schematic shows
If you have a specific problem (like broken chorus or distorted sound), let me know the ! Review: Roland JC-120 Guitar Amp When the chorus is engaged