Scala 2 SynthEdit Microtuner


Licensing and Requirements

The Scala 2 SynthEdit Microtuner is free for use in SynthEdit. VSTs made with the Microtuner require a license to remove a per-session time limitation (session time expiration has no impact on VST other than microtonality). Licenses are portable registration codes obtained by email to .

Donations are requested but not required for VST licenses. A Developer license is needed to create VSTs whose time limits can be unlocked. Either VST or Developer registration covers any number of microtuned VSTs, support, and all future upgrades.

The Microtuner is compatible with all versions of SynthEdit running in XP, Vista, or Windows 7. XP users may need a minor Microsoft upgrade for newer C++ libraries (details in theDownloads & Registration section).

If there is any cause for dissatisfaction, the purchase price less Paypal fee ($0.75 USD) is refundable within 30 days.

Please contact me at if you have any questions.

Getting Started

When the Microtuner is inserted as a module into a SynthEdit project, it is exposed as a graphic element of the instrument's front panel displayed by click on a related button or image. A dropdown list is linked to the Microtuner to provide selection among loaded tunings.

Microtuner Menu

Microtuner Menu

Picklist of loaded tunings

Picklist of loaded tunings

If no scale is selected from the dropdown, microtuning is bypassed and the VST synth plays in conventional twelve tone equal temperament, with no loss of CPU performance. The Microtuner has a timer limitation in demo mode - after a few minutes the dropdown list clears itself and the synth reverts to twelve tone equal temperament. (Reloading the VST will restore saved tunings and restart the timer.)

To get started, you will need some Scala format tuning files. This format is a simple, widely adopted text file that describes tunings as a series of cent value or fractional scale steps. The Huygens-Fokker Foundation maintains a website at that describes the format and offers a large, downloadable archive of tunings.

Click here for a popup with more info on the Scala format.


Clicking the Tunings option of the Microtuner's popup menu opens the following screen (shown here with four tunings loaded):

Tuning Screen

Scala 2 SynthEdit Tuning Config Screen

The tunings screen has four panes:

All of the settings described above apply to a single VST patch. If you want to use the settings on another patch, click the Patch Copy button, and close the Tuning screen.  Select the destination patch, open the Tuning screen again, and click the Patch Paste button. Thats a bit of effort, but at least the tunings on the two patches will persist from one saved Host session to the next. (Bank tunings will be implemented in a future release.)


The Defaults menu option opens this screen:


Scala 2 SynthEdit Default Settings Screen

Reset restores the defaults to those shown above. Save commits any edits on this screen to the current patch memory. After saving, Apply to Patch copies the current default values for midi key number and pitch to the four tunings of the current patch.


The Registration menu option opens this screen:


Scala 2 SynthEdit Registration Screen

If you want to build the Microtuner into your own projects, download the Scala2SETuner.dll, save it to a folder in the modules directory, and open its registration screen from within a SynthEdit project.

Host Setup

The Microtuner doesn't impose any limits on polyphony or the number of instances of a VST in a host. Accordingly, it should have no impact on usage of a microtuned VST for play in 12 tone equal temperament.

Typically in a mult-timbral setting, each instance of a microtuned VST will be playing on its own channel. If modulation and/or scale change control is desired, the VST needs to be connected to these channels as well. If the VST has an internal channel filter between its midi-in and midi-to-control-voltage components, the VST can simply be connected to an 'All' channel midi feed, with the internal midi filter set to the midi stream for its' music part. So for example, if an instance of the synth should play the channel 2 midi stream and get key changes from channel 16, the synth instance would be connected to the host's midi 'All' stream and its internal channel filter would be set to channel 2.

If the microtuned VST doesn't have an internal midi filter, then a modular VST host will be needed to route multiple midi paths to the VST to give it a music part channel plus key and/or scale channels, with some pitch/volume work-around for the occasional note on a control note channel. (Velocity mapped to 0, etc.)

As shown below, if multiple instances of microtuned VSTs are set to the same key change or scale channel, then monophonic play of notes on these channels can control real-time ensemble retuning.

Example of key change track

Sequencer key change track centered around midi note 60 (C3)

Developer Info

The Microtuner can be added to any SynthEdit project that uses the standard 1 volt/octave control model for its oscillators. The microtuner is rescaling 'voltage' based on cent intervals of scale steps, where one octave equals 1,200 millicents.

To insert the Microtuner in an existing project, first make note of all wire paths from the pitch pin of the Midi to CV module. The Scala 2 SynthEdit module is then inserted in the project, and the starting points of these paths are moved from the Midi to CV module to the pitchCV_Out pin of the Microtuner module. A single wire is added to connect the pitch pin of the Midi to CV module to the pitchCV_In pin of the Microtuner. A wire is then run from the Midi Input of the containers' IO module to the Midi In pin of the Microtuner. Finally, add a Dropdown List Subcontrol and wire it to the Scale List pin of the Microtuner.

As described in the 'Host Setup' section above, a channel selector should be connected to the channel pin of the Midi to CV module to facilitate key and scale change by the Microtuner.

Wiring layout

Pin connection example for the Scala 2 SynthEdit module

Note: the "Scale List" pin is not exposed until a Developer registration has been entered. If the Developer registration is entered from within a SynthEdit project, the Microtuner module will need to be deleted and re-added to the project to get a fresh build with the Scale List pin.

The Microntuner can be inserted in complex synths with no problem. Here it is in the SynthEdit demo, "Poly Synth":

Wiring example

Scala 2 SynthEdit module in the PolySynth demo