This page is read from MIDI Instrument Definitions, a Python library used in the author's other projects, in which every number is traced to a document its maker published. Its source is on GitHub.

Roland JU-06A MIDI implementation

The MIDI implementation of the Roland JU-06A: what it answers to, and the 63 controls it offers.

At a glance

Firmware: Not recorded.
MIDI channel: Any one of 1 to 16.
Modes: sound_module.
Control Surface Mode: the controls on the base MIDI channel do not answer in it.
Parts: Control surface: on the base MIDI channel, taking nothing, in Control Surface Mode only.
MIDI mode: 3: omni off, poly.
Voices: 4, or 1 as set on the instrument.
Note range: 0 to 127: C-1 to G9, counting middle C as C4.
Velocity: Sent and received. Release velocity is ignored.
Aftertouch: None, sent or answered.
Pitch bend: How far it bends is not recorded, and the range can be changed.
Program change: Received and sent, with 64 presets.
MIDI clock: Sent and received.
Start and stop: Sent and received.
Control change: 63 controls, in the tables below.
NRPN: None.
System exclusive: None.

Controls

In the order the definition gives them, by part and group. Under each control is the name a program calls it by, once pymidiinstrumentdefs.load("roland/ju_06a") has loaded them.

On the base MIDI channel

These answer in sound_module, and not in Control Surface Mode.

DCO

Control	CC	Values
DCO RANGE `dco_range`	12	0-127
DCO LFO `dco_lfo`	13	0-127
DCO PWM `dco_pwm`	14	0-127
DCO LFO/MAN/ENV `dco_lfo_man_env`	15	0-127
DCO SQR SW `dco_sqr_sw`	16	0-127
DCO SAW SW `dco_saw_sw`	17	0-127
DCO SUB `dco_sub`	18	0-127
DCO NOISE `dco_noise`	19	0-127
DCO SUB SW `dco_sub_sw`	28	0-127

HPF

Control	CC	Values
HPF FREQ `hpf_freq`	20	0-127

VCF

Control	CC	Values
VCF ENV Polarity `vcf_env_polarity`	21	0-127
VCF ENV `vcf_env`	22	0-127
VCF LFO `vcf_lfo`	23	0-127
VCF KYBD `vcf_kybd`	24	0-127
VCF RES `vcf_res`	71	0-127
VCF FREQ `vcf_freq`	74	0-127

VCA

Control	CC	Values
VCA ENV / GATE `vca_env_gate`	25	0-127
VCA LEVEL `vca_level`	26	0-127

Envelope

Control	CC	Values
ENV S `env_s`	27	0-127
ENV R `env_r`	72	0-127
ENV A `env_a`	73	0-127
ENV D `env_d`	75	0-127

LFO

Control	CC	Values
LFO RATE `lfo_rate`	3	0-127
LFO DELAY `lfo_delay`	9	0-127
LFO WAVE `lfo_wave`	29	0-127
LFO TRIG `lfo_trig`	30	0-127

Delay

Control	CC	Values
DELAY TIME `delay_time`	82	0-127
DELAY FEEDBACK `delay_feedback`	83	0-127
DELAY SW `delay_sw`	89	0-127
DELAY LEVEL `delay_level`	91	0-127

Chorus

Control	CC	Values
CHORUS OFF / I / II / I+II `chorus_off_i_ii_i_ii`	93	0-127

Portamento

Control	CC	Values
PORTAMENTO TIME `portamento_time`	5	0-127
PORTAMENTO SW `portamento_sw`	65	0-127

Performance

Control	CC	Values
MODULATION `modulation`	1	0-127 Received, never sent
EXPRESSION PEDAL `expression_pedal`	11	0-127 Received, never sent
HOLD `hold`	64	0-127 Received, never sent
BEND RANGE `bend_range`	87	0-127

Voice

Control	CC	Values
POLY / (POLY) / SOLO / UNISON `poly_poly_solo_unison`	86	0-127
TEMPO SYNC `tempo_sync`	88	0-127

Control surface

In Control Surface Mode only.

DCO

Control	CC	Values
DCO SQR SW `surface_dco_sqr_sw`	16	0-127 Sent, never received
DCO SAW SW `surface_dco_saw_sw`	17	0-127 Sent, never received
DCO SUB `surface_dco_sub`	18	0-127 Sent, never received
DCO NOISE `surface_dco_noise`	19	0-127 Sent, never received
DCO LFO `surface_dco_lfo`	26	0-127 Sent, never received
DCO RANGE `surface_dco_range`	47	0-127 Sent, never received
DCO PWM `surface_dco_pwm`	50	0-127 Sent, never received
DCO LFO / MAN / ENV `surface_dco_lfo_man_env`	60	0-127 Sent, never received

HPF

Control	CC	Values
HPF FREQ `surface_hpf_freq`	79	0-127 Sent, never received

VCF

Control	CC	Values
VCF FREQ `surface_vcf_freq`	3	0-127 Sent, never received
VCF RES `surface_vcf_res`	9	0-127 Sent, never received
VCF LFO `surface_vcf_lfo`	28	0-127 Sent, never received
VCF ENV `surface_vcf_env`	81	0-127 Sent, never received
VCF KYBD `surface_vcf_kybd`	82	0-127 Sent, never received

VCA

Control	CC	Values
VCA ENV / GATE `surface_vca_env_gate`	88	0-127 Sent, never received
VCA LEVEL `surface_vca_level`	110	0-127 Sent, never received

Envelope

Control	CC	Values
ENV A `surface_env_a`	83	0-127 Sent, never received
ENV D `surface_env_d`	84	0-127 Sent, never received
ENV S `surface_env_s`	85	0-127 Sent, never received
ENV R `surface_env_r`	86	0-127 Sent, never received

LFO

Control	CC	Values
LFO DELAY `surface_lfo_delay`	27	0-127 Sent, never received
LFO RATE `surface_lfo_rate`	29	0-127 Sent, never received

Chorus

Control	CC	Values
CHORUS OFF / ON `surface_chorus_off_on`	12	0-127 Sent, never received
CHORUS I / II `surface_chorus_i_ii`	70	0-127 Sent, never received

Where these facts come from

Source documents

JU-06A MIDI Implementation Chart, multi02, dated 5 September 2019, its MIDI implementation, read on 6 October 2026 (the file read).
JU-06A Owner's Manual, eng02, dated 6 August 2019, its user manual, read on 6 October 2026 (the file read).
JU-06A Sound List, e01, its user manual, read on 6 October 2026 (the file read).
Roland - Support - JU-06A - Owner's Manuals, its download page, read on 6 October 2026 (the file read).

How they were read

The JU-06A MIDI Implementation Chart, two pages, "Date: Sep. 5, 2019" (chart p. 1); the JU-06A Owner's Manual, two large sheets; and the JU-06A Sound List. All three are offered on Roland's owner's manuals page for this product, which is saved beside them.

THE CHART IS THE SOURCE OF EVERY NUMBER AND IT IS TEXT RATHER THAN DRAWINGS. Roland set it in Excel, so every o and x is in the text layer - which is worth saying beside the Korg volca bass read three ranks earlier, whose chart of the same era draws its marks as paths and returns none of them to a text extraction.

TWO MAPS, AND BOTH ARE BELOW, EACH IN ITS MODE. See the comment above the definition for the overlap. What page 2 is, for a reader who meets it (chart p. 2): 24 controller numbers, every one transmitted and none recognised, which is the instrument working as a controller for something else; they are the surface part's controls below. It also sends notes where the sound module map receives them - 60 to 71 from the bank and memory buttons, 48 to 72 from the optional keyboard unit - and transmits active sensing and nothing else. A part records what it receives and not what it sends, so those notes are said here.

THE TWO PAGES DIFFER IN ONE MORE WAY WORTH NOTING: page 1's basic channel is 1 to 16 both ways and page 2's is 1 transmitted and nothing recognised. So by its chart the control surface sends on channel 1, where the sound module's channel is a setting - "Specifies the MIDI transmit/receive channel (1-16). Default: 1 ch" (manual p. 2) - and no page says whether the surface follows that setting. Nor does any page say whether it follows the one that decides where the sound module's panel sends its controller messages, "Control Change Output Mode" (manual p. 2), whose default is USB alone.

WHAT THE OTHER TWO DOCUMENTS SETTLE. The manual gives the polyphony, the three voice modes, the bend range's span, the channel and its default, and the mode that selects page 2. And it gives one thing no chart could: "Although the JU-06A is four-note polyphonic, you can increase the polyphony by using a MIDI cable to connect two or more JU-06A units and turning Chain mode on." (manual p. 2), where the fifth note and those after it leave by MIDI OUT for the next unit. The sound list names 128 patches, not 64, as this file said until 2026-10-11: two lists of 64 headed 60 and 106, which the manual explains as "64 sounds taken from the JUNO-60 (8 patches × 8 banks) and another 64 sounds taken from the JUNO-106" (manual p. 1), chosen between by a panel switch: "Switches between JUNO-60 sounds and JUNO-106 sounds." (manual p. 1). The chart's program change range, 0 - 63, reaches 64 of them at a time, and no page says it can reach the other side's.

RECORDED AS ABSENT: aftertouch, a cross in both columns of both charts, and system exclusive likewise. The note range is 0 to 127 on page 1 and is recorded.

NOT RECORDED: page 2's two narrower ranges, which are notes the surface sends and which no field holds. And the firmware, which no document states - see model.