The Roland JC-120 is a 120-watt stereo amplifier featuring two independent 60-watt power sections. This true stereo design is critical to its signature sound: the dry signal is sent to one speaker while the pitch-modulated signal is sent to the other, creating "Dimensional Space Chorus" through acoustic air mixing. The JC-120 features two channels:
, a benchmark solid-state amplifier first introduced in 1975 and still in production today. 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 The Roland JC-120 is a 120-watt stereo amplifier
: Early versions (pre-1979) often featured different Bucket Brigade Device (BBD) chips, such as the MN3002, while later revisions moved to the MN3004. Discrete vs. Op-Amp JC-120 UT / JT (2nd Edition - these
A straightforward clean channel with a 3-band EQ and a "Bright" switch.
Attempting to repair a JC-120 without its schematic is like navigating a city without a map. Here is why:
has several distinct schematic versions depending on the manufacturing year and serial number. Most technical searches for a "JC-120 schematic" yield the or the 1984 head model (JC-120H) diagram , which varies significantly from combo versions. Available Schematics & Service Manuals