Dexed - FM Plugin Synth

Dexed is a multi platform, multi format plugin synth that is closely modeled on the Yamaha DX7. Under the hood it uses music-synthesizer-for-android for the synth engine and JUCE as a plugin wrapper.

The goal of this project is to be a tool/companion for the original DX7. Sound engine with 'float' value parameters, different waveform à la TX81z would be great but anything that goes beyond the DX7 should and will be a fork of this project. This is to keep the compatibility with the original machine.

Dexed is licensed on the GPL v2. The msfa component (acronym for music synthesizer for android, see msfa in the source folder) stays on the Apache 2.0 license to able to collaborate between projects.

Features

• Multi platform (OS X, Windows, Linux) and multi format (VST, AU and others that I don't use); by using JUCE
• The sound engine music-synthesizer-for-android is closely modeled on the original DX7 characteristics
• 144 DAW automatable DX7 parameters available from one single panel
• Fully supports DX7 input and output Sysex messages; including controller change. This means that you can use this with a native DX7/TX7 as a patch editor
• Each operator have a realtime VU meter to know which one is active
• Can load/save any DX7/TX7 sysex programs. It is also possible to save a single program into a different sysex file.

Changelog

Version 0.6.0 (current sprint)

• Added external midi interface to send / receive sysex messages
• Fix Tracktion crash upon startup
• Middle C (transpose) now works
• Mouse over the interface controls now tells what it does without having to change it

Version 0.5.1

• Fix distortion issue with FL (DAW blocksize not multiple of 64)
• OS X 64bit build (the VST package contains both 32bit and 64bit)

Version 0.5.0

• Linux support
• Fix large DAW blocksize with midi events

Version 0.4.0

• Modulation wheel support
• Now using the Obxd 4-pole lowpass filter implementation
• Pitchbend range / step
• Output/Volume VU status

Binary downloads

Dexed is not a finished product but it is stable enough to be used in a DAW environment: in normal operation it shouldn't crash and the VST state saving works. If you don't see the new version here but you see it in the change log, it's because this version is in development (current sprint). Only officials (tested) builds are listed here.

• Version 0.5.1 vst win32 - vst win64 - vst os x
• Version 0.5.0 vst win32 - vst win64 - vst os x
• Version 0.4.0 vst win32 - vst win64 - vst os x
• Version 0.3.0 vst win32 - vst win64 - vst os x

Using as a DX7 editor

You can use this plugin to edit your real DX7 patchs. Since midi send/receive are quirky for the majority of VST hosts, any sysex messages (editor messages) must be send or received with the external Dexed midi interface, configurable in the "PARM" panel. By setting a DX7 in / DX7 out, Dexed will listen to specific program/cartridge changes from your DX7 and send controller/program/cartridge you edit.

Prerequisite

• Before you use this interface, your DX7 must be configured to send or receive sysex messages. By hitting [FUNCTION] and [8] button :
• The first one is the midi channel. By reading some of DX7 literature, most DX7 are supposed to support only 1 channel. Unless you are running a cluster of DX7, you should keep this to 1.
• The second one (press [8] again) is "SYS INFO AVAIL" or "SYS INFO UNAVAIL". Keep it to "SYS INFO AVAIL" to be able to receive sysex messages.
• The third one, you need to remove MEMORY PROTECT on the internal or cartridge memory to be able to receive a Dexed 32 voice bulk dump.

To send to your DX7

• If the midi port is configured, any parameter change will be sent to your DX7.
• Use the [SEND] button on Dexed to send program or cartridge changes to your DX7. Be sure you have set [MEMORY PROTECT] to off so the cartridge (internal et external one) on the DX7 can be overridden.

To receive to your DX7

• Receive a program by simply using [MEMORY SELECT] then the program you want to change ([1] to [32]).
• Receive a cartridge by pressing [FUNCTION] then 3 times on [8] you should see " MIDI TRANSMIT ? ". If you hit yes, Dexed should receive the complete cartridge.

Troubleshooting

• If the midi ports are opened correcly you should see a DX7 light flashing when you send or receive midi data from/to your DX7. If you don't see anything, or just the input, it because it was unable to open the output midi interface.
• If you play on your DX7 keyboard, the |DX7 In light| should be flashing. Use this to test the midi in communication.
• If you click/play on the Dexed virtual keyboard, it will send the correspoding midi note to the DX7 port; if configured. Use this to test the midi out communication.
• If the data sent is corrupted (wrong checksum, DX7 crash); it might be the midi interface implementation. Default Windows USB midi driver can send corrupt sysex data. If it is the case, use a third party device (like the midiman uno) that have his own USB driver.
• If you are unable to open the interface (error message after the [PARM] dialog), it might be because the midi driver doesn't support multiple clients (common on Windows). Be sure that there are no other applications that are using the same midi interface.

Randomized programs

Dexed doesn't check the sysex checksum so you can load any type of files. If the checksum doesn't match, it will tell you but load it anyway. This feature act as a kind of a randomization for DX programs.

Warning: loading corrupt/random data can crash the plugin and ultimatly your DAW. I'm doing my best to filter out values that can crash the DX engine; but I keep it to the minimum to get the digital circuit bending feel.

Saving those corrupt/random sysex data will regenerate a 32 bulk program sysex dump with a valid checksum for your DX7 keyboard. I'm in now way responsible if this breaks your DX7 keyboard.

FAQ (possibly)

• Some programs can generate distortion : This is because the voice summing still needs some tuning. You can simply lower the volume on those programs.
• Some sysex seems to be corrupted : Even if the sysex checksum doesn't match, Dexed will try to load it (this is a kind of randomize feature). Right now Dexed supports only original DX7 sysex, other DX family sysex (like the DX21) is considered as random data.
• Dexed doesn't receive/send parameter data from/to my DX7 : Most DX7 parameter change are done via sysex and very few VST host actually implements sysex. Configure this plugin to send sysex data to a specific midi interface (see PARM panel).

Credits & thanks

• DX Synth engine : Raph Levien and the msfa team
• LP Filter : Filatov Vadim (2DaT); taken from the excellent Obxd project
• DX7 program compilation : Jean-Marc Desprez (author of SynprezFM)
• DX7 programs : Dave Benson, Frank Carvalho, Tim Conrardy, Jack Deckard, Chris Dodunski, Tim Garrett, Hitaye, Stephan Ibsen, Christian Jezreel, Narfman, Godric Wilkie
• markusthegeek direct implication for this project

TODO - Dexed

• Yamaha 4 operators (DX21/DX27/DX100) sysex import
• Implement a better DX look and feel (amp, pitch, algo) *** commin Q4 2014
• Various code cleanup

TODO - msfa

• The sample rate should not change the response of the envelopes
• Portamento implementation
• LFO/Mod-wheel amplitude
• Algo 4 & 6 feedback