Two separate solid-state power amplifiers driving two independent 12-inch speakers.
: 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
Roland historically provided service notes. The most reliable free sources: jc-120 schematic
Transitioned to the quieter MN3007 BBD chip, updated the distortion circuit from a harsh diode-clipper to a smoother operational amplifier configuration, and standardizing plastic jacks over metal ones.
The pitch-modulated delay signal is sent exclusively to the Right power amplifier. Because the left speaker pumps out pure dry signal and the right speaker pumps out modulated wet signal, the "chorus" effect actually blends acoustically in the air, creating a massive, three-dimensional stereo image. 5. Dual Power Amplifiers Op-Amp Roland historically provided service notes
uses two separate 60-watt power amplifiers to drive two 12-inch speakers independently. 120W total (60W + 60W into 8Ω).
carries the completely dry, unmodulated guitar signal. Because the left speaker pumps out pure dry
A straightforward clean channel with a 3-band EQ and a "Bright" switch.
The Ultimate Guide to the Roland JC-120 Schematic: Understanding the King of Clean The Roland JC-120 Jazz Chorus Go to product viewer dialog for this item.