MidiDisp dispatcher

Overview

MidiDisp firmware routes MIDI notes and related messages received on one MIDI channel to several channels. This allows you to play a set of monophonic synths as one poly-synth or layer synths played using a single keyboard.

MidiDisp_small

The functionality is similar to the one provided by Mutable Instruments MIDIpal “dispatch” app with a few differences:

  • MidiDisp can send more than one note to the same channel, allowing you to use polyphonic synths as targets. For example, you can build a SEM Four Voice out of a SEM Two Voice and two SEM modules, or extend polyphony of a poly-synth with limited amount of voices and no poly-chain capability (KORG Volca FMs, etc.)
  • MidiDisp can lock output channel allowing you to play multiple sound modules using one MIDI keyboard with instant switching between them.
  • MidiDisp can transpose MIDI notes according to per-output channel settings, which is great for layering sounds.
  • MidiDisp can send legato notes to the same output channel.
  • MidiDisp correctly handles large amount of MIDI output when dispatching pitch bend and controller change events to large amount of output channels.

Resources

MidiDisp runs on MidiGAL hardware, however you can also run it on MidiBUD and, with some limitations due to the lack of the switch, on any Mutable Instruments MIDIpal compatible hardware.

Firmware (.syx and .hex): MidiDisp_100 (use mididsp_pal.syx if your device has MIDIpal bootloader)

User interface

MidiDisp user interface consists of pages which are selected by encoder rotation. Each page displays a single parameter value.

Clicking the encoder activates parameter value editing mode. In this mode parameter value is displayed in square brackets. Rotating the encoder changes the parameter value. Clicking the encoder again accepts the updated parameter value.

Double clicking the encoder saves all device settings in the currently selected program slot. The Main page allows you to save current program into a different memory slot.

Pressing the switch executes the currently selected switch action. Available switch actions are Hold Channel and Lock Channel. Hold Channel action locks output channel changes while the switch is held down. The Lock Channel action locks output channel changes until the switch is pressed again.

Clicking the encoder while holding down the switch sends All Notes Off message on all output channels. Double clicking the encoder while holding down the switch sends All Notes Off message on all sixteen MIDI channels.

Main page

00 ____
12345678

Main page is shown when the device powers up. It displays currently selected program number and its name in the top row. Bottom row displays currently active output channels.

Click the encoder to activate program selection mode. While in this mode, program name is displayed in square brackets and rotating the encoder selects the program to load. Clicking the encoder again loads the selected program.

00[AtEx]

Press the switch while in program selection mode to activate program name editing mode. In this mode program name is displayed in square brackets and with blinking cursor. Pressing the switch advances editing character position and encoder rotation selects the character under the blinking cursor. Clicking the encoder again accepts the program name changes.

Input channel page

In Chnl
 1

Specifies input MIDI channel. Click and rotate the encoder to select the input channel. Click the encoder again to accept the selected input channel.

MIDI Note and related events received on the input channel will be routed to the output channels according to the selected dispatch mode.

Messages received on all other channels will be passed to MIDI OUT as is, providing “soft” MIDI THRU functionality.

Output channels page

Out Chnl
123456__

Specifies up to 8 output MIDI channels. Click the encoder to enter output channel selection mode.

Press switch to select the output channel. Rotate encoder to change MIDI channel for the selected output channel. Rotate encoder all the way counterclockwise to remove the selected output channel. Click the encoder again to accept the selected output channels.

Note that you can assign a MIDI channel to more than one output channel. For example, selecting channels ‘2237’ will send the first and the second notes to MIDI channel 2, third to MIDI channel 3 and fourth to MIDI channel 7.

Dispatch mode page

Dispatch
 cyclic

Specifies note dispatch mode. Click and rotate the encoder to select the dispatch mode. Click the encoder again to accept the selected dispatch mode.

Following are the available dispatch modes:

  • Cyclic: each new note is cyclically played on the next output channel.
  • Polyphonic: the mapping of notes to output channels uses a true voice stealing algorithm which tries to reuse the same channel for occurrences of the same note.
  • Random: each new note is routed to a random channel.
  • Velocity: the louder (higher velocity) the note, the higher the output channel it is sent to.
  • Stack: each note is sent to all channels at the same time. Perfect for thickening a lead by sending it to several synths, or to several parts of the same multi-timbral device.

These dispatch modes mimic the ones available in Mutable Instruments MIDIpal Dispatcher app.

Legato mode page

Legato
 off

Enables legato mode. In this mode legato notes will be sent to the same output channel the first note was sent to, so all the legato notes are played using the same voice.

Click and rotate the encoder to enable or disable legato mode. Click the encoder again to accept the selection.

Switch action page

Switch
holdCh

Specifies switch action which will occur when the switch is pressed.

Available switch actions are:

  • Hold Channel: locks output channel changes for the time the switch is held down.
  • Lock Channel: locks output channel changes until the switch is pressed again.

Hold and Lock Channel actions are useful when playing ambient and drone like tunes using layered sound modules.

Channel transposition page

Transpos
5_______

Specifies MIDI note transposition for each of the output channels. Click the encoder to enter output channel transposition selection mode. Press switch to select the output channel. Rotate encoder to change transposition for the selected output channel. Click the encoder again to accept the selected output channel transpositions.

Miscellaneous

Powering the device up with the switch pressed initializes the device erasing all settings in all program slot to default values.

Powering the device up with the encoder knob pressed enters the firmware upgrade mode: device expects firmware sysex file to be sent to MIDI IN.