KQ Dixie

KQ Dixie is a 6-Operator FM synthesizer that is modeled on the synthesizer which appeared on the 1980s.

Frequently Asked Questions
Contact Information is here.
Reference manual is here.
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KQ Dixie Icon
KQ Dixie
Ryouta Kira
Download on the App Store


FM synthesizers make sounds with Frequency Modulation.
FM brings rich and brilliant sounds which are impossible to create with analog one.
It makes very complex waves with simple modulations.
The same method is used for a radio.
The synthesizer gained much popularity in the 1980s.

This app lets you make sounds freely with 156 voice parameters.
Almost all parameters but multi-timbres, unisons, filters, and delay are compatible with Yamaha DX7 mark I.

Audio Unit v3 compatible.
Audiobus compatible.
32 algorithms included.
You can manage the hardware DX7 when it is connected with external MIDI cables.
Supports DX7 System Exclusive Messages (SysEx) and syx files.
Supports Zip files.
You may be able to find a lot of patches on the internet.
A Multi-timbre, Unison function is included.
May be available to connect Korg Volca FM via an audio cable / MIDI.

URL Scheme: kqdixie://

About Audiobus

Introducing Audiobus support: Now you can stream live audio directly to other Audiobus-compatible apps! See http://audiob.us for more information.

KQ Dixie Icon
KQ Dixie
Ryouta Kira
Download on the App Store

Bug Information

Version 3.1.7

Some parameters (Portamento and Pan) did not have any changes.
This bug was fixed on version 3.1.8.

Version 2.4.9 or below

The portamento went wrong if middle C is not C3 and is in poly mode.
Also, “suskey P retain” and “suskey P follow” may be reversed on the param screen.
This bug was fixed on version 3.0.

Version 2.4.7

The app crashes when you have no extra files.
This bug was fixed on version 2.4.8 or above.

Version between 2.3 and 2.3.2

Detune did not work if Engine Version is 1 or above.
This bug was fixed on version 2.3.3 or above.

Version between 2.2 and 2.2.2

Multiple feedback operators did not sound. (Algorithm 4 and 6)
This bug was fixed on version 2.2.3 or above.

Version 2.0 and 2.0.1

Function Parameters were not saved.
The parameters will be saved in a dxpf file on version 2.0.2 or above.

Version 1.0.5 or below

LFO on amplitude modulation was inverted.
(Saw up should have increased the amplitude but actually decreased.)
This bug was fixed on version 1.0.6 or above.

Version 1.0.1 or below

The app might crash if iCloud is off.
This bug was fixed on version 1.0.2 or above.

Version 1.0

The app crashed when file name contains spaces and/or other special characters.
This bug was fixed on version 1.0.1 or above.

KQ Dixie Icon
KQ Dixie
Ryouta Kira
Download on the App Store

Update history

Date Format: Year-Month-Day.

Version 3.1.11

Bug-fix: Fixed a crash that occured when adding/removing folders.
Bug-fix: Fixed some UI controls.

Released on 2023-8-21.

Version 3.1.10

Bug-fix: A feature that “Just Open” syx files was not working.
Other fixes.

Released on 2023-6-6.

Version 3.1.9

Changed appearance in some sizes.

Released on 2023-4-23.

Version 3.1.8

Bug-fix: It was fixed that some parameters (Portamento and Pan) did not have any changes.

Released on 2023-3-16.

Version 3.1.7

Improved “breath to velocity” type c.
Added “smooth control”.

Released on 2023-3-8.

Version 3.1.6

New: Added “breath to velocity” type c for wind instruments.
Bug-fix: “breath to velocity” settings were not loaded.

Released on 2023-3-7.

Version 3.1.5

Improved Audio Unit View on GarageBand on iPhone.
Added Aftertouch Knob and you can assign Aftertouch.
Other fixes.

Released on 2023-1-21.

Version 3.1.4

Added Tip Jar (for iOS/iPadOS 15 or later).
The minimum supported OS version is 12.4.

Released on 2023-1-6.

Version 3.1.3

Behavior during MIDI transmission has been changed. In particular, behavior in converter mode has been improved.
The pitch of high note has been corrected.
Other fixes.

Released on 2022-12-24.

Version 3.1.2

Refined controller behavior.
Especially, EG bias with lower range is improved.
Changed some labels.

Released on 2022-12-12.

Version 3.1.1

Filter became slower. It became more smooth when changing the parameters.
Other fixes.

Released on 2022-12-1.

Version 3.1

Added velocity curve function.
Added breath controller to velocity function.
Changed appearance.
You can turn off auto detection when assigning MIDI CC.

Released on 2022-11-28.

Version 3.0.5

Fixed a rare crash.

Released on 2022-10-7.

Version 3.0.4

It was fixed that The MIDI messages were invalid if you sent a normal MIDI message after sending SysEx in iOS/iPadOS 14 or later.
Improved Volca FM linkage.
It was fixed that you were not able to load the patch in bank A-C when you connected a MIDI destination.

Released on 2022-9-12.

Version 3.0.3

Added MIDI Conversion. You can control the output device from the input device.
Now you can change MIDI Send Channel.
Added Note on/off settings in MIDI Filter.
Fixed device ID of SysEx to 0 in Volca FM mode.

Released on 2022-9-11.

Version 3.0.2

MIDI Sources’ settings were lost when “Connect All MIDI Sources” was being off.
Fixed some Japanese translations.
Small fixes.

Released on 2022-9-6.

Version 3.0.1

Fixed some Japanese translations.
Small fixes.

Released on 2022-9-5.

Version 3.0

1 staging bank and 3 static banks.
Supported Volca FM. You can transmit the patch via MIDI or an Audio Cable.
64 factory patches.
Added locking features when loading a file.
Fixed portamento bugs.
Now you can turn off low-pass filter and delay effector.
Other fixes.

Released on 2022-9-4.

Version 2.4.9

A bug in the time processing was fixed.

Released on 2022-4-8.

Version 2.4.8

Fixed a crash bug.

Released on 2021-12-22.

Version 2.4.7

The previous Audio Units are deprecated. This is because they fail validation in Logic Pro and MainStage. I plan to keep them for compatibility, but please attention.
This app may work on Apple Silicon Mac although I don’t have the new machine yet.

Added support for iPad portrait screen.
Fixed the appearance on iPad without a home button.
Optimized process.
Stop supporting 32bit architecture.
Required iOS 10.0 or above.
Other fixes.

Released on 2021-12-20.

Version 2.4.6

  • Updated SDK.
  • Released on 2021-9-25

Version 2.4.5

  • Fixed rare crashes.
  • Released on 2021-5-16

Version 2.4.4

  • Fixed a crash bug.
  • Added a workaround for processing MIDI.
  • Some other fixes.
  • Released on 2021-2-7

Version 2.4.3

  • Fixed an issue that Automatic Omni mode was applied when loading a state in Audio Unit extension.
  • Some other fixes.
  • Released on 2020-10-20

Version 2.4.2

  • Updated Audiobus SDK.
  • Released on 2020-9-7

Version 2.4.1

  • Fixed a bug which occurred with large iPhone.
  • Released on 2020-7-30

Version 2.4

  • Supports Multiple-Out (“KQ Dixie Multi” Audio Unit). Use it with some supporting hosts such as AUM and apeMatrix.
  • Released on 2020-7-23

Version 2.3.7

  • Fixed a crash bug which occurs in iOS 14 (beta).
  • Released on 2020-7-2

Version 2.3.6

  • Buffer size has more option.
  • Changed Delay behavior.
  • Released on 2020-6-23

Version 2.3.5

  • Bug-fix: The app might have crashed when deleting folders.
  • Released on 2020-6-6

Version 2.3.4

  • Small fixes.
  • Released on 2020-5-6

Version 2.3.3

  • Bug-fix: Detune did not work.
  • Released on 2020-5-1

Version 2.3.2

  • Fixed a bug that tuning name was not able to be edited.
  • Released on 2020-4-26

Version 2.3.1

  • Changed the wording.
  • Fixed some bugs around micro tuning.
  • Released on 2020-4-25

Version 2.3

  • Supports Micro-Tuning. Now Dixie can play microtonal notes.
  • Added a function to connect with “FM Piano”, an app of mine.
  • Modified File Processing.
  • Modified behaviors of VU Meter.
  • Other fixes.
  • Released on 2020-4-23

Version 2.2.4

  • Added a color to patches when saving the current patch into a bank.
  • Released on 2020-3-9

Version 2.2.3

  • Bug-fix: Multiple feedback operators didn’t sound. (Algorithm 4 and 6)
  • Sounds can be updated when you tweak levels even if notes are sustained.
  • Released on 2020-2-24

Version 2.2.2

  • Fixed behaviors that the first note was not turned on when the second note was released on Mono mode.
  • Released on 2020-2-21

Version 2.2.1

  • Bug-fix: The app crashed when there were a lot of files.
    I recommend you place zip files instead of extracting them.
  • Bug-fix: The app might have crashed when opening a CC Scene file.
  • Released on 2020-2-9

Version 2.2

  • Added features:
    • Adjust Carrier’s Level. (Enable if you feel distorted sound, for example, when you use unison.)
    • Engine Version 3.
    • 12bit Engine.
  • Changed features:
    • Engine Version. (was simulate level)
    • Improved sample rate.
    • Velocity behavior at a virtual keyboard.
    • Other small fixes.
  • Released on 2020-2-5

Version 2.1.1

  • Bug-fix: A list of files except iCloud might not have been updated.
  • Released on 2020-1-13

Version 2.1

  • Added Accurate Simulation Level 2 (Previously “More Accurate Simulating” option):
    • More similar to DX7 when Envelope L1=0.
  • Changed Envelope views when L4 is not 0.
  • Bug-fix: The app might have crashed on 32-bit devices.
  • Updated Audiobus SDK.
  • Released on 2020-1-8

Version 2.0.9

  • Fixed the appearance on iOS 13.
  • Released on 2019-11-4

Version 2.0.8

  • Bug-fix: SysEx could not be opened at Files.app on iOS 13.
  • Added Import function.
  • Updated Audiobus SDK.
  • Released on 2019-10-22

Version 2.0.7

  • Fixed issue: Keys were pressed permanently when 3 finger touching.
  • Released on 2019-9-12

Version 2.0.6

  • Displays an X when a timbre is muted.
  • Resets status of mute when a Dixie Performance is loaded.
  • Released on 2019-8-15

Version 2.0.5

  • Fixed some bugs:
    • Undo didn’t work on a subfolder in a Zip file. (Undo & Redo make choosing a patch much easier.)
    • Quick-Save might not have worked.
  • Other small fixes.
  • Released on 2019-8-14

Version 2.0.4

  • Added some multi-timbre settings:
    • Mode of Patch Values
    • Mode of Program Change / Dump
  • Released on 2019-6-21

Version 2.0.3

  • Updated Audiobus SDK.
  • Released on 2019-6-18

Version 2.0.2

  • Bug-fix: Function Parameters were not saved or restored.
  • Some words have been modified.
  • Other small fixes.
  • Released on 2019-5-31

Version 2.0.1

  • Added a MIDI Filter.
  • Bug-fix: An OP may have oscillated when disabling the OP at a specific algorithm.
  • Other small fixes.
  • Released on 2019-5-4

Version 2.0

  • New Features:
    • Multi-timbre, Unison.
    • VU Meter.
    • New File Type: Dixie Performance.
    • Improved File Management.
    • Supported more SysEx.
    • Volume Boost.
    • Soft Keyboard Velocity Sensitivity.
    • Can modify the number of Soft Keyboard White Keys.
    • Undo, Redo.
  • Bug-Fixes:
    • AudioUnit Polyphony bug.
    • Other fixes.
  • Released on 2019-4-30

Version 1.2.3

  • The envelope speed was wrong when sample rate is not 44100Hz.
  • Released on 2019-3-25

Version 1.2.2

  • Bug-fix:
    • The sustain damper pedal was not reset when receiving CC#121.
    • Wrong version was displayed on Settings.app.
  • Other small fixes.
  • Released on 2019-1-14

Version 1.2.1

  • Maximum polyphony is 512.
  • Other small fixes.
  • Released on 2019-1-6

Version 1.2

  • MIDI CC Assignment. You can control all parameters via hardware MIDI knobs and sliders.
  • Added MIDI Output on Audio Unit Extension. You can record knob controls to some AU host on iOS 11 or above.
  • Supported “32 stripped 1 voice” (4960 bytes file).
  • Added links to my web site.
  • Changed Keyboard behavior.
  • Other small fixes.
  • Released on 2018-12-12

Version 1.1.6

  • Supports iOS 12.1.
  • Changed the behavior of Safe Area on Audio Unit.
  • Released on 2018-11-13

Version 1.1.5

  • Bug-fix: The layout collapsed when opening a file on iPhone which has a notch.
  • Other small fixes.
  • Released on 2018-10-12

Version 1.1.4

  • Added a “Init” patch.
  • Enabled a directory, “On My iPhone/iPad” at Files.app.
  • Released on 2018-10-4

Version 1.1.3

  • A bug-fix: The Zip-like files were always opened in KQ Dixie at Files.app.
    As a side effect, “KQ Dixie” disappears from “On My iPhone/iPad” at Files.app.
    In addition, Zip and Syx files may not open out from Files.app when you installed the past version once.
    In that case, Copy files to iCloud, Start KQ Dixie application, and Open them.
  • Released on 2018-9-22

Version 1.1.2

  • iOS 12 support.
  • The character size at the patch list on the cart has become larger on iPhone.
  • Other small fixes.
  • Released on 2018-9-14

Version 1.1.1

  • Bug-fix: SysEx files were labeled as unsupported when you added those via iTunes.
  • Released on 2018-2-21

Version 1.1

  • Added More Accurate Emulating option.
  • Fixed a glissando behavior.
  • Released on 2018-2-21

Version 1.0.9

  • The Inter-App Audio panel was not displayed when launching from the host.
  • Released on 2018-2-14

Version 1.0.8

  • Fixed Audiobus issue.
  • Supports 32-bit devices (no guarantee).
  • Released on 2018-2-7

Version 1.0.7

  • You can choose on-screen velocity slider or modulation wheel.
  • Improved memory management.
  • Other small fixes.
  • Released on 2018-1-30

Version 1.0.6

  • LFO was inverted on amplifier modulation.
  • Sometimes LFO parameters were not loaded.
  • Released on 2018-1-24

Version 1.0.5

  • Specific Zip files caused App crash.
  • Folder structure in specific Zip files was wrong.
  • Released on 2018-1-21

Version 1.0.4

  • The Audio Unit screen size is flexible if the host supports it.
  • You can hide the on-screen keyboard.
  • The app detects the character encodings of Zip files automatically.
  • Bug-fix: Displaying files had a glitch at the first launch.
  • Other small fixes.
  • Released on 2018-1-19

Version 1.0.3

  • New feature: Quick-Saving.
  • Saving 32+1 voices supported.
  • Renaming files supported.
  • Exporting files supported.
  • You can hide unsupported files in Zip files.
  • Reduce noises when volume or pan changed.
  • Some crash bugs are fixed.
  • Other small fixes.
  • Released on 2018-1-16

Version 1.0.2

  • Copying files supported.
  • Folder view in Zip archive supported.
  • Fixed some crash bugs.
  • Released on 2018-1-13

Version 1.0.1

  • Bug-fix: The app crashes when file name contains spaces.
  • Released on 2018-1-11

Version 1.0

  • The first release.
  • Released on 2018-1-11

KQ Dixie Icon
KQ Dixie
Ryouta Kira
Download on the App Store

Yamaha DX7 is a trademark of Yamaha Corporation.
Volca is a trademark of Korg Inc.
I have no business relations with Yamaha and Korg.