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.

Sequential Prophet X MIDI implementation

The MIDI implementation of the Sequential Prophet X: what it answers to, and the 598 controls it offers, on firmware 2.2.2.0.0.

At a glance

Firmware

This page describes firmware 2.2.2.0.0.

MIDI channel

Any one of 1 to 16.

Voices

8, 16, or 32, 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

Channel pressure and polyphonic, each answered. It sends aftertouch too.

Pitch bend

How far it bends is not recorded, and the range can be changed.

Program change

Received and sent, with 1024 presets.

MIDI clock

Sent and received.

Start and stop

Received.

Control change

90 controls, in the tables below.

NRPN

Supported, and preferred to CC. 508 of the controls below have one.

System exclusive

Supported.

Controls

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

Sample playback

Oscillators

Mixer

Filter

Filter envelope

Amplifier envelope

Auxiliary envelopes

Low frequency oscillators

Modulation

Effects

Arpeggiator

Sequencer

Clock

Unison

Master volume/program volume

Glide

16-Voice mode

Pitch and mod wheels

Touch sliders

Global settings

Without a group

Where these facts come from

Source documents

• Prophet X User’s Guide, 1.3, dated February 2021, its user manual, read on 8 October 2026 (the file read).
• Prophet X/XL OS 2.0 Addendum, 2.0, dated November 2018, its user manual, read on 8 October 2026 (the file read).
• Prophet X OS 2.2 Addendum, 2.2, dated February 2020, its user manual, read on 8 October 2026 (the file read).
• Prophet X OS Main v.2.2.2.0.0, 2.2.2.0.0, dated 2 February 2022, its release notes, read on 8 October 2026 (the file read).
• Prophet X Documentation - Sequential, its download page, read on 8 October 2026.
• Prophet X Operating System - Sequential, its download page, read on 8 October 2026.

How they were read

The Prophet X User's Guide, Version 1.3, February 2021, 88 sheets, all but four of which carry two printed pages, cited by printed page: the sound banks at p. 4, layers at pp. 9 to 13, the sequencer's MIDI transport at p. 68, the pitch bend range at p. 80, the Global Settings at pp. 122 to 128, the alternative tunings at p. 132, and Appendix E, the MIDI implementation, at pp. 140 to 156. The OS 2.0 and 2.2 addenda. The readme inside the newest OS file, 2.2.2.0.0. And Sequential's documentation and operating system pages for the Prophet X.

ONE APPENDIX HOLDS EVERY NUMBER. Appendix E prints the received and transmitted channel messages (pp. 141 to 143), a table of controller numbers (p. 144), the NRPN format (pp. 145 and 146), a global table (p. 147), a program table (pp. 148 to 151), one control NRPN and the system exclusive messages (pp. 152 to 156). It is not the whole story: its own list of the globals that affect MIDI (guide p. 140) leaves out Multi Mode and Local Control, which are in the Global Settings (guide pp. 123 and 124). Neither addendum adds a controller or an NRPN. Both describe features "not covered in the main User’s Guide" (os_2_2 p. 1), which means an earlier edition: guide 1.3 is the newer, and already carries OS 2.0's 64 alternative tunings (guide p. 132). The documentation page lists the guide, the two addenda and a factory preset list (documentation_page).

A PARAMETER TRAVELS AS A CONTROLLER OR AS AN NRPN, AND A GLOBAL CHOOSES WHICH. A global, MIDI Param Send, is off, CC or NRPN: "Changes to the values of front panel controls are transmitted via MIDI as Continuous Controllers (CC) or Non-Registered Parameter Number (NRPN)." (guide p. 140); MIDI Param Receive has the same three, and "NRPNs are the preferred method of parameter transmission, since they cover the complete range of all parameters, while CCs are limited to a range of 128." (guide p. 140). The controller table's numbers "are transmitted when MIDI Param Send is set to CC, and recognized/received when MIDI Param Receive is set to CC." (guide p. 144), and the NRPNs "are transmitted when MIDI Parameter Send is set to NRPN in globals, and received when MIDI Parameter Receive is set to NRPN in globals." (guide p. 145). The synth also takes NRPN data increment and decrement, and the RPN reset (guide p. 145).

THE NRPN PAGES MISPRINT TWO THINGS A SENDER NEEDS. The received list prints the RPN reset under 0010 0101 and 0010 0100 (guide p. 146), controllers 37 and 36, where MIDI's registered parameter number controllers are 101 and 100. And p. 145 says that when a number or a value is broken into two seven-bit bytes, "in most cases the MSB will be zero or one, and never more than two" (guide p. 145), which the tables do not bear out: layer A's numbers reach 409, an MSB of 3, layer B's start at 2048, an MSB of 16, the globals' run from 4102, an MSB of 32, and the program table's values reach 999, an MSB of 7.

THE CONTROLLERS AND THE NRPNS ARE NOT PAIRED. sequential/take_5, sequential/prophet_6 and sequential/fourm put a controller and an NRPN on one control where their tables give one parameter, and sequential/prophet_6 does so where its two tables name it differently. Here the controller table gives one number for a parameter where the NRPN table gives one for each layer, and outside Multi Mode no page says which layer a controller reaches - so the 90 controllers are controls of their own, and so is every NRPN.

TWO LAYERS, AND THE PROGRAM TABLE NUMBERS BOTH. "The two layers are referred to as Layer A and Layer B." (guide p. 9); they stack or split, and the edit layer b button chooses which the panel edits (guide pp. 10 to 13). The program table's 241 rows each give a layer A number, 0 to 409, a layer B number 2048 higher, a name, printed under the heading Value, and a range, printed under Description (guide pp. 148 to 151), so each row is two controls here, its label the name with , layer A or , layer B. A global, Multi Mode, puts the layers on two channels: "When Multi Mode is on, the Prophet X responds to MIDI data on two consecutive MIDI channels" (guide p. 123), so "Layer A (voices 1-4) will respond to MIDI channel 1 and Layer B (voices 5-8) will respond to MIDI channel 2." (guide p. 124) for a base channel of 1, or voices 1 to 8 and 9 to 16 in 16-voice mode (guide p. 124). While it is on, the channel says which layer a controller reaches. No part is recorded for that, because it holds only while Multi Mode is on and no page gives its default.

EIGHTY-SEVEN CONTROLLERS, AND FIVE FAULTS AROUND THEM. The controller table has 88 rows and 87 numbers (guide p. 144): 62 is printed twice, Clock Divide both times. Controller 8 is Sub Oscillator, and no other page of the guide names a sub oscillator. The transmitted list prints Expression: When assigned to Pedal/CV against 0000 1101 (guide p. 143), which is 13 - the controller table's A/B Mode - where the Global Settings give the expression controller as Exp CC11 (guide p. 125). Volume, 7, is on the transmitted list twice, for a pedal and for the volume knob (guide p. 143). And five numbers on the received and transmitted lists are not in the controller table. Three are here as well: 2 Breath Controller, transmitted only, 4 Foot Controller and 74 Brightness (guide pp. 142 and 143). The other two are received only, 123 All Notes Off and 121 Reset All Controllers (guide p. 142), channel mode messages, which this corpus does not record as controls; sequential/prophet_5 says the same of the same two.

THE GLOBAL TABLE DISAGREES WITH ITSELF IN THREE ROWS, AND WITH THE GLOBAL SETTINGS IN MORE. Its 25 rows (guide p. 147) match the global dump's "50 nibbles (LS then MS) for 25 Global parameters" (guide p. 155). MIDI Out Select is printed 0-2 over four named values, 0 to 3, and Sustain Polarity 0-1 over four; the controls here hold the values the rows name. MIDI Clock Mode is printed 0-4 and names four. Against the Global Settings: the clock modes are five, the fifth slave no s/s, which the row does not name (guide p. 122); Local Control has a third value, Key/Wheels Off (guide p. 124), and the SysEx cable a third, None (guide p. 123), which their rows have no number for; Master Fine is -50…+50 (guide p. 122) where its row is 0-50; and Sustain Polarity is Normal, Reversed (guide p. 127). Since OS 2.0 Sustain Arp has a third mode too, arp hold mom (os_2_0 p. 5), where its row is 0-1. Each is noted on its control. And three rows carry markers: MIDI Param Send and Local Control are marked *, "Controller received, but not transmitted." (guide p. 147), and MIDI Param Receive †, "Controller transmitted, but ignored when received." (guide p. 147); all three are recorded as marked.

1024 PROGRAMS, FOUR ADD-ON BANKS, AND THE PAGES NUMBER THE BANKS THREE WAYS. "The Prophet X contains a total of 1024 programs." (guide p. 4), and "Each bank has 128 programs" (guide p. 4), four user banks and four factory banks. Four more, A1 to A4, are add-on banks: "Programs included with sample expansion libraries from sound developers will load here." (guide p. 4), and they are outside that count. Bank select is controller 32 alone; no controller list or table has 0. It is received as "1 - 4 select user banks 1 - 4; 5 - 8 select factory banks 1 - 4; 9 - 12 select add-on banks 1 - 4 others ignored" (guide p. 142), so a bank select of 0 is ignored, and transmitted as Bank Select: 0 - 9 (guide p. 143). A program change is received as "0-127 for Programs 1-127 within current Bank" (guide p. 141) and transmitted as "0-127 for Programs 00-128 within current Bank" (guide p. 142). The system exclusive request names banks 0 to 7 and programs 0 to 127 (guide p. 153), and the program dump banks 0 to 9 and programs 0 to 99 (guide p. 154), each bank number in a byte printed 0000 00vv, two bits wide, which holds 0 to 3. MIDI Prog Enable decides whether a program change is answered (guide p. 141), and by the Global Settings whether one is sent too: the synth "will transmit them (when prompted) to the MIDI Out." (guide p. 123).

CLOCK BOTH WAYS, AND TRANSPORT RECEIVED. MIDI Clock Mode is off, master, slave, slave thru or slave no s/s, the last of which "Receives MIDI Clock but does not respond to MIDI Start or Stop command." (guide p. 140), and MIDI Clock Cable chooses whether clock is received at the MIDI port or over USB (guide p. 140). The sequencer starts and stops "using MIDI start/stop messages sent from a DAW or other MIDI device." (guide p. 68). The implementation's real-time table lists only the timing clock (guide p. 141), and no page says the Prophet X sends a start or a stop.

NOTES, PRESSURE AND BEND. Note off is received with "Velocity is ignored" (guide p. 141) and sent with a velocity of 0 (guide p. 142). Polyphonic key pressure and channel pressure are received (guide p. 141), and channel pressure alone is sent (guide p. 142). Pitch bend travels both ways (guide pp. 141 and 142), and its range is set up and down separately, each up to 12 semitones (guide p. 80), 0 to 12 in the program table (guide p. 151). Since OS 2.0 the arpeggiator and sequencer send notes too, while a global the addendum calls both midi arp notes and midi arp+seq is on (os_2_0 pp. 5 and 6): "The arpeggiator and sequencer now output MIDI note numbers." (os_2_0 p. 5). The MIDI channel is 1 to 16 or All: "All receives on all 16 channels." (guide p. 140).

EIGHT VOICES, SIXTEEN OR THIRTY-TWO. "The Prophet X is an 8-voice stereo/16-voice mono, bi-timbral, hybrid digital/analog synthesizer" (guide p. 1), and "Polyphony is halved in Stack mode" (guide p. 10). OS 2.0 adds a third: "Prophet X OS version 2.0 adds a new 32-voice performance mode" (os_2_0 p. 3). Sixteen voices is a program parameter, 16Voices in the program table, 0 or 1 (guide p. 151); the 32-voice mode is entered by holding the 16 voice button down (os_2_0 p. 4), and no table gives it a number. So voicing_modes holds 8, 16 and 32, and no polyphony is recorded as the default.

SYSTEM EXCLUSIVE BOTH WAYS. The Prophet X answers a device inquiry, "always responds if 0vvvvvvv = 0111 1111" (guide p. 152), sends program, edit buffer, global and sample name dumps when asked (guide pp. 153 and 154), and sends program, bank and playlist dumps from the Global menu (guide p. 128). Every one of the eleven messages on pp. 152 to 155 starts 1111 0000, and two also end with it, in the place of the end of exclusive: the request for sample names (guide p. 153) and the playlist dump (guide p. 155). The other nine end 1111 0111. The program dump is "4096 bytes expanded to 4683 MIDI bytes" (guide p. 154), and the page on the packing says "it takes 4690 MIDI bytes to transmit 4683 Program data bytes." (guide p. 156), so the two disagree about what 4683 counts. And the global table speaks of "the global data sent and received on global parameter dumps" (guide p. 147), where "The Global Parameters Data Dump is not recognized when received." (guide p. 155).

NOT RECORDED, AND WHY:

• a MIDI mode, which no page names;
• a default for any global but Local Control's and Mono/Stereo's, the two the Global Settings give (guide p. 124), which are recorded - the third default the guide gives, "standard, chromatic western tuning."

(guide p. 132), has no number in the Alt. Tunings row, and Filter Pedal Mode's "default operation of controlling filter cutoff" (guide p. 125) does not say which of its two filter settings, LPF Full or LPF Half; and the polyphony default above.