Scala 2 SynthEdit Microtuner
Features
- Enables VST functionality to browse, edit, and load text file
tuning definitions written in the Scala file format.
- Microtunings are fully polyphonic with negligible incremental
CPU load. Supports up to 127 scale degrees and non-octave based
tunings. Resolution is 1,200,000 pitches per octave. Centerpoint
note and pitch can be specified independently for each
tuning.
- Saves up to 4 tunings per patch to VST host memory. Tunings
are selectable by picklist. Each tuning has associated tuning
parameters which are saved with the host, so projects can be
resumed with all settings intact. Tunings can be copied from one
patch to another.
- Integrated note channel control of microtonal key changes and
scale selection. Key and scale changes can be made in real-time
by simply playing notes above or below specified centerpoints on
designated midi channels. Flexible centerpoint assignment enables
use of footpedals, second keyboards, or split keyboards to make
key and scale changes. Per-tuning starting pitch assignment
facilitates pivots from one scale into another.
- Each tuning can be modulated by the step intervals of itself
or any of the other tunings in its patch. Key modulation source
is an attribute of individual tunings, and is retained with the
patch.
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
robert@12equalboresme.com .
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
robert@12equalboresme.com 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.
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
http://www.xs4all.nl/~huygensf/scala that describes
the format and offers a large, downloadable archive of
tunings.
Click here for a popup with more info on the Scala format.
Tunings
Clicking the Tunings option of the Microtuner's popup menu
opens the following screen (shown here with four tunings
loaded):
The tunings screen has four panes:
- Tunings - Displays four slots that can receive tunings for
the current synth patch. Click a radio button to select a target
slot for one of the button actions Load, Clear, Settings -
Get/Save
- Browser - Shows the contents of a .scl file selected by the
Browse button from a normal Windows file navigation screen. The
contents of the browser pane can be edited to rename a tuning or
adjust a scale. Clicking the Load button runs an internal process
that translates the scale to cents and places it in the selected
tuning slot of the current patch. After a tuning has been loaded,
clicking its radio button will show the cent values for the
tuning in the Browser pane.
- Per Tuning Settings - Click the Settings Get and Save buttons
to control the following parameters independently for each
tuning:
- Start Key # - Midi keyboard key number (1-127) of the first
note of the selected tuning.
- Start Pitch (Hz) - Starting pitch in hertz of the first note
of the selected tuning.
- Key Intervals from Tuning # - Specifies which tuning among
the 4 slots of the current patch is the source of modulation
intervals for the selected tuning. Say the selected tuning is
slot 1 and slot 3 has a thirteen note scale that spans a little
over an octave. Saving a setting of 3 for the slot 1 tuning means
that modulation intervals for the slot 1 tuning are derived from
the thirteen steps of tuning slot 3. (If a new tuning is loaded
in slot 3, slot 1 modulation is taken from the new tuning.)
- Global Settings - These settings are shared by the four
tunings at the patch level, although it is probably more useful
to treat them as unchanging from patch to patch. They specify the
midi channels and key number centerpoints for signalling key or
scale changes in real-time. So if the key change channel is 16
and the centerpoint is midi key # 60 (middle C), playing note #63
modulates to the 3rd scale degree of the modulation source
tuning. The number of scale degrees in the modulating tuning is
applied as a modulus, so for a twelve note scale starting at key
#60, pressing key #80 plays sets the new root to the pitch of
scale degree eight of the modulating scale (80 - 60 = 20, and the
remainder of 20/12 = 8). Playing below the centerpoint descends
from the top degree of the modulating scale.
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.)
Defaults
The Defaults menu option opens this screen:
- Start Key # - Default midi note number for scale degree 0 of
newly added tunings.
- Start Pitch (Hz) - The Microtuner holds 2 values that may be
toggled as the default pitch for the specified Start Key #
- Scale and Key Change - Default values for midi channel and
starting key.
- Oscillator 'A' Pitch (Hz) - Typically, SynthEdit
octave-per-volt style oscillators default to a 440 A reference
pitch for midi note number 69. If the VST's master tuning has
been raised or lowered by a few cents, the new master pitch
should be entered here.
- Move Centerpoint with Key - When checked, finger position is
moved to play the tonic of the new key (normal keyboard
practice). When unchecked, the new tonic is on the default start
key.
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.
Registration
The Registration menu option opens this 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.
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.
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":
