Roland · Amp

Roland Jazz Chorus JC-120 Settings Guide

The Roland JC-120 Jazz Chorus is one of the most influential amplifiers ever made, introduced in 1975 and unchanged in fundamental character since. A solid-state 120-watt stereo amp with built-in stereo chorus, it produces one of the cleanest, most transparent tones available from any amplifier. The JC-120 is the definitive choice for jazz, funk, and clean-tone genres, and has been used by artists across a remarkable range of styles: from Andy Summers and Robert Smith to Albert King and Radiohead.

Used by: Robert Smith, Andy Summers

The best Roland Jazz Chorus JC-120 settings start with: Volume at 6/10, Bass at 5/10, Middle at 5/10, Treble at 6/10, Chorus Rate at 4/10, Chorus Depth at 3/10, Vibrato at 0/10. Adjust from there based on your amp, guitar, and room volume. For Jazz: Volume 6/10, Bass 6/10, Middle 6/10, Treble 4/10, Chorus Rate 0/10, Chorus Depth 0/10, Vibrato 0/10.

What Each Control Does

Volume
Silent
Full
Clean channel output volume. At higher settings, the solid-state preamp produces a subtle, pleasant clipping character distinct from tube breakup.
Bass
Cut
Boost
Low-frequency tone control. The JC-120 bass response is wide and authoritative.
Middle
Cut
Boost
Mid-range tone control — the JC-120's midrange is particularly smooth, lacking the nasal character of many solid-state amps.
Treble
Dark
Bright
High-frequency tone control. At maximum Treble, the JC-120 produces a crystalline sheen that defines its iconic character.
Chorus Rate
Slow
Fast
Chorus LFO speed. The JC-120's analog bucket-brigade chorus is widely considered the finest built-in amp chorus ever produced.
Chorus Depth
Subtle
Maximum
Chorus intensity. Even at maximum depth, the JC-120's chorus avoids the artificial quality of digital approximations.
Vibrato
Off
Maximum
Engages vibrato mode (pitch modulation rather than amplitude/pitch chorus). Creates a dramatic warble effect used in psychedelic contexts.

Recommended Starting Settings

Safe starting positions for any style. Adjust from here based on your amp and room.

6
Volume
5
Bass
5
Middle
6
Treble
4
Chorus Rate
3
Chorus Depth
0
Vibrato

All values on a 0–10 scale. These are starting points — fine-tune by ear.

Settings by Genre

Jazz
Volume6
Bass6
Middle6
Treble4
Chorus Rate0
Chorus Depth0
Vibrato0

Pure clean tone with no chorus. Treble 4 produces the warm, round character preferred in jazz. Bass and Middle up to provide a full, authoritative tone. The JC-120 without chorus is one of the finest jazz amplifiers ever made — its solid-state character actually suits jazz's demand for frequency-honest amplification. A guitar's natural pick attack and wood resonance come through accurately.

Funk
Volume6
Bass5
Middle5
Treble7
Chorus Rate0
Chorus Depth0
Vibrato0

Bright, clean, and percussive for the cutting funk clean tone. Treble 7 adds the upper-frequency bite needed for funk rhythms to cut through a horn section. Use a wah pedal and envelope filter in front of the JC-120 — the amp's transparency lets both effects perform at their best. No chorus.

Blues
Volume7
Bass5
Middle7
Treble5
Chorus Rate0
Chorus Depth0
Vibrato0

The JC-120 suits blues when played at higher Volume settings where the solid-state preamp starts to produce its characteristic slight overdrive. Middle 7 adds the vocal blues tone. For overdriven blues, place a Tube Screamer or Blues Driver in front and let the JC-120 remain clean while the pedal drives.

Indie
Volume6
Bass5
Middle5
Treble6
Chorus Rate4
Chorus Depth5
Vibrato0

The JC-120 with its built-in chorus at moderate depth is the quintessential indie rock clean tone — used by The Cure, New Order, and many 80s post-punk bands. Chorus Rate 4 (moderate speed) with Depth 5 produces the shimmering wash without sounding artificially processed.

Classic Rock
Volume6
Bass5
Middle6
Treble6
Chorus Rate0
Chorus Depth0
Vibrato0

Run a Marshall-style overdrive pedal (OCD, Blues Breaker, or Hot Cake) in front of the clean JC-120 for classic rock tones. The amp's clean headroom means the overdrive character comes entirely from the pedal — a very different approach to a cranked Marshall but effective for controlled, studio-quality distortion.

Artist Settings

Documented settings used by professional guitarists on this unit.

Volume6
Bass5
Middle5
Treble6
Chorus Rate4
Chorus Depth6
Vibrato0

The Cure's Robert Smith built his signature sound entirely around the JC-120 with built-in chorus. Chorus Depth 6 at Rate 4 produces the shimmering, slightly watery tone heard on Disintegration and Boys Don't Cry. Combined with a Roland Space Echo and his Roland GR-300 guitar synth, this is the classic The Cure clean tone.

Volume5
Bass5
Middle5
Treble6
Chorus Rate5
Chorus Depth7
Vibrato0

The Police's Andy Summers used a JC-120 as his main amp throughout the band's classic period. His approach: chorus at higher depth, combined with a Roland RE-301 Space Echo and various modulation pedals. The Chorus Depth at 7 produces the distinctive shimmering that characterises Every Breath You Take.

Tips & Common Mistakes

  • The JC-120's built-in stereo chorus sounds better than virtually any chorus pedal you can buy — don't bypass it in favour of a pedal unless you specifically need a different sound.
  • The JC-120's Distortion channel (on models that have it) is not its strength — the amp is unmatched for clean tone. Drive any overdrive from an external pedal.
  • The amp responds extremely well to playing dynamics — your pick attack, picking position, and volume knob on the guitar all come through accurately. Practising on a JC-120 teaches good technique.
  • In stereo configurations, connect two JC-120s or use the stereo outputs — the stereo spread of the chorus at full width is spectacular for ambient and post-rock styles.
  • The JC-120 works exceptionally well with bass-heavy chords (open tunings, drop-D) because the solid-state power amp handles the low end with more authority than typical tube amps of similar wattage.

Roland Jazz Chorus JC-120 — Common Questions

Best starting settings for Roland Jazz Chorus JC-120: Volume at 6/10, Bass at 5/10, Middle at 5/10, Treble at 6/10, Chorus Rate at 4/10, Chorus Depth at 3/10, Vibrato at 0/10. Adjust from there based on your guitar, room, and playing style.

For Jazz: Volume 6/10, Bass 6/10, Middle 6/10, Treble 4/10, Chorus Rate 0/10, Chorus Depth 0/10, Vibrato 0/10. Pure clean tone with no chorus. Treble 4 produces the warm, round character preferred in jazz. Bass and Middle up to provide a full, authoritative tone. The JC-120 without chorus is one of the finest jazz amplifiers ever made — its solid-state character actually suits jazz's demand for frequency-honest amplification. A guitar's natural pick attack and wood resonance come through accurately.

For Funk: Volume 6/10, Bass 5/10, Middle 5/10, Treble 7/10, Chorus Rate 0/10, Chorus Depth 0/10, Vibrato 0/10. Bright, clean, and percussive for the cutting funk clean tone. Treble 7 adds the upper-frequency bite needed for funk rhythms to cut through a horn section. Use a wah pedal and envelope filter in front of the JC-120 — the amp's transparency lets both effects perform at their best. No chorus.

Volume: Clean channel output volume. At higher settings, the solid-state preamp produces a subtle, pleasant clipping character distinct from tube breakup. (Silent to Full). Bass: Low-frequency tone control. The JC-120 bass response is wide and authoritative. (Cut to Boost). Middle: Mid-range tone control — the JC-120's midrange is particularly smooth, lacking the nasal character of many solid-state amps. (Cut to Boost). Treble: High-frequency tone control. At maximum Treble, the JC-120 produces a crystalline sheen that defines its iconic character. (Dark to Bright). Chorus Rate: Chorus LFO speed. The JC-120's analog bucket-brigade chorus is widely considered the finest built-in amp chorus ever produced. (Slow to Fast). Chorus Depth: Chorus intensity. Even at maximum depth, the JC-120's chorus avoids the artificial quality of digital approximations. (Subtle to Maximum). Vibrato: Engages vibrato mode (pitch modulation rather than amplitude/pitch chorus). Creates a dramatic warble effect used in psychedelic contexts. (Off to Maximum)

The JC-120's built-in stereo chorus sounds better than virtually any chorus pedal you can buy — don't bypass it in favour of a pedal unless you specifically need a different sound. The JC-120's Distortion channel (on models that have it) is not its strength — the amp is unmatched for clean tone. Drive any overdrive from an external pedal. The amp responds extremely well to playing dynamics — your pick attack, picking position, and volume knob on the guitar all come through accurately. Practising on a JC-120 teaches good technique. In stereo configurations, connect two JC-120s or use the stereo outputs — the stereo spread of the chorus at full width is spectacular for ambient and post-rock styles. The JC-120 works exceptionally well with bass-heavy chords (open tunings, drop-D) because the solid-state power amp handles the low end with more authority than typical tube amps of similar wattage.

Robert Smith settings: Volume 6/10, Bass 5/10, Middle 5/10, Treble 6/10, Chorus Rate 4/10, Chorus Depth 6/10, Vibrato 0/10. The Cure's Robert Smith built his signature sound entirely around the JC-120 with built-in chorus. Chorus Depth 6 at Rate 4 produces the shimmering, slightly watery tone heard on Disintegration and Boys Don't Cry. Combined with a Roland Space Echo and his Roland GR-300 guitar synth, this is the classic The Cure clean tone.

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