Jc-120 Schematic May 2026

She found it tucked behind the peeling fiberboard of her late father’s workbench, sandwiched between a dead 9-volt battery and a dog-eared copy of Guitar Player magazine. Her father, Silas, hadn’t spoken to her in eleven years. He hadn’t spoken to anyone, really. He just repaired amplifiers for ghosts—old men with tremors and vintage Les Pauls who wanted to hear their youth one more time before their hearing went.

A memory amplifier.

She started at the input jack—top left. A simple ¼" TS. Then a JFET transistor, 2SK117. She remembered her father’s journals now: “The first gain stage must be silent. No hiss. No prayer. Just the string.” The signal then split. That was the secret of the JC-120. Not one path, but two. The famous stereo chorus was born from a bucket-brigade device (BBD), the MN3002. A chip that literally passed voltage like a line of firefighters passing a bucket of water from input to output. The clock speed of that transfer created the shimmer—the microscopic delay that made the sound wider than a cathedral. jc-120 schematic

Elena turned off the amplifier. The silence was absolute. But the schematic was still on the table. And she understood now what he had been trying to say, not through words, but through voltage, resistors, and the cruel, beautiful architecture of a stereo chorus.

She sat on the garage floor, listening to her own words decay into noise. And then, between the 127th and 128th repeat, she heard something else. She found it tucked behind the peeling fiberboard

The JC-120 had been his obsession. A solid-state behemoth from 1975. Stereo chorus that sounded like angels falling down a staircase. Clean headroom for days. No tubes to replace, no temperamental heat. Just pure, crystalline, unforgiving clarity. Silas used to say, “A tube amp lies to you. It warms up your mistakes. But the Jazz Chorus? The Jazz Chorus tells the truth.”

To Elena, it was a suicide note.

Some delays are not bugs. They are features.