Tubbutec mTune User manual

Tubbutec µ Tune user manual
http://tubbutec.de
March 11, 2020
1

Contents
1 Introduction 4
1.1 Introduction to microtonality . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2 Aboutthismanual................................ 4
1.3 µ Tuneuserinterface............................... 5
1.4 Connectingexpanders .............................. 6
1.5 Blockdiagram .................................. 7
2 Menu 8
2.1 Mainmenu.................................... 8
2.2 INFO....................................... 9
2.3 CONF ...................................... 10
2.3.1 Channel conguration . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.3.2 Midiconguration............................ 14
2.3.3 MISCmenu ............................... 16
2.3.4 Firmwarereset.............................. 16
2.4 TUN ....................................... 17
2.4.1 Loadascale ............................... 17
2.4.2 Saveascale ............................... 17
2.4.3 Scaleeditor ............................... 18
2.4.4 Navigation in scale editor . . . . . . . . . . . . . . . . . . . . . . . . 18
2.4.5 Editscales................................ 18
2.4.6 Scalemapping.............................. 20
2.5 TOOLS...................................... 21
2.5.1 Midimonitor............................... 21
2.5.2 VCOcalibration ............................. 21
2.5.3 Clockgenerator ............................. 21
2.5.4 Autotuning ............................... 22
3 How to's 23
3.1 Quantizing.................................... 23
3.2 MiditoCV.................................... 23
3.3 CVtoMidi.................................... 25
3.4 Miditomidituning ............................... 26
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3.5 Scalemapping.................................. 27
3.6 VCOcalibration ................................. 29
3.7 Auto-tuning ................................... 30
3.8 Hz/V....................................... 32
3.8.1 How to nd the correct V/Hz setting for a synths or linear VCO . . . . 33
4 Midi controller CC numbers 34
5 Terms used in this manual 35
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1 Introduction
Tubbutec µ Tune is a powerful quantizer, midi to CV interface, CV to midi interface, midi router
and general multitool with a lot of features. The two channels of the main module can be
expanded to up to 8 channels using µ Tune expanders. µ Tune has many features dealing with
microtonal music or generally precise pitch: you can load, edit and save scales and tunings,
and it includes a tuner, VCO calibration and even real-time automatic tuning.
µ Tune is not limited to one function at a time. You can route midi midi between DIN and
USB, create midi and merge it with existing notes, quantize using a microtonal scale and
measure a VCO's frequency all at the same time.
1.1 Introduction to microtonality
Microtonality and alternative tuning systems is a vast and complex topic that can not be
covered in this manual.
As a rst introduction we recommend the video Lecture on microtonality with the Tubbutec
µ Tune, a presentation by Phineas De Thornley Head and Matt Ward.
It can be found in our Youtube channel or via the link:
https://www.youtube.com/watch?v=uf_zMCUrqBA
A more in depth introduction can be found here:
https://www.britannica.com/art/tuning-and-temperament
We also warmly recommend to check out Sevish, whose albums are a great example of ap-
proachable microtonal music and whose scale packs can be found on the µ Tune SD card.
https://sevish.com
Sevish is also the creator of Scale Workshop, a browser based scale creator completely
compatible with µ Tune:
https://sevish.com/scaleworkshop/
Speaking of scale creation: The mother of all tools is of course Scala by Manuel Op de
Coul.:
http://www.huygens-fokker.org/scala/
Its .scl format can directly be read and modied by µ Tune. Manuel also generously provided
the interval name list used in µ Tune's own scale editor.
1.2 About this manual
This user manual rst describes all features and settings that can be found in the µ Tune menu.
It then shows typical use cases with examples in the HOW-TO section. This includes examples
for quantizing, midi handling, microtonal work and auto-tuning.
This manual describes the features of µ Tune rmware version 2.00. Manual version 2.00
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1.3 µ Tune user interface
Figure 1: µ Tune interface overview, the main module is 8HP wide, the expander is 2HP
1. DIN-midi input
2. DIN-midi output
3. Mini-USB provides USB midi. µ Tune acts as a USB device.
4. Slot for a micro SD card. The card is inserted with its 'tooth' pointing to the left
5. OLED display
6. Knob and ENTER button for menu navigation.
7. Back button. Will always bring you back to the previous menu page.
8. CV-in channels 1 and 2 and expander channels
9. GATE-in channels 1 and 2 and expander channels
10. CV-out channels 1 and 2 and expander channels
11. GATE-out channels 1 and 2 and expander channels
12. Expander status LED. Shows expander power (green) and GATE-out states (red and blue)
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1.4 Connecting expanders
Up to three expanders can be connected to the µ Tune main module. Each expander adds two
complete µ Tune-channels with CV-in, GATE-in, CV-out and GATE-out. The expanders are
connected to the main module using ribbon cables and are fully powered by the main unit.
WARNING! DO NOT CONNECT THE EXPANDERS WHILE THE MAIN MOD-
ULE IS POWERED.
This might damage the main module or the expander.
The expanders are connected as shown in Image 2. The connector on top of the expanders is
connected to the main module or bottom connector of the previous expander.
Figure 2: Connecting several expanders.
On startup µ Tune will automatically detect the number of connected expanders and shows the
correct number of channels in the main menu.
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1.5 Block diagram
Below is a block diagram which shows the most important parts of µ Tune's signal ow. Only
one channel is shown.
Figure 3: Simplied µ Tune functional ow chart
The input voltage at CV-in is converted to a note number in the quantizer. It uses hysteresis
at its input in order to lter noisy signals. The quantizer can work in free-running mode, or be
triggered or gated by the signal at the GATE input. GATE-in can also provide other functions
such as measuring frequency for the tuner, or trigger a random transpose.
A second possible source of note numbers is midi. Midi note events coming from either USB-
midi or DIN-midi are routed in the midi router and passed to the voice assigner. Here note
and gate signals are created depending on the voice assign mode and output conguration.
Dual mono, or several dierent duo phonic voice assign modes are available.
The note numbers are then passed to the scale mapper. Here, they are converted to a pitch
value via the currently loaded scale. Parameters such as Transpose or Scale Shift are included
as well as the VCO correction factors. An optional exponential converter can also be activated,
converting between v/Hz and v/oct standards. At the end of this signal chain sits a 16 bit
DAC, which turns the value into a high precision voltage between 0V and 10V.
The GATE-out can output Midi Start/Stop signals, Midi clock with adjustable divider or midi
gate from the voice assigner.
The conguration of input and output functions is dynamic and reacts to whether CV-in and
GATE-in are plugged in. Functions can be dened freely for each possible combination of
these. This way µ Tune can change its function based on what you intend to do, without
having to change a lot of settings rst.
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2 Menu
2.1 Main menu
Figure 4: Main menu with 2 channels (no expander)
The main menu shows an overview of µ Tune's status and also contains four sub-menus. Simply
enter these menus by navigating to them with the navigation knob and press enter.
On the left side you can see the status of channels 1 and 2. The right pointing arrow shows
the GATE-in status. It becomes thicker if the gate is active. Next to it, the 'input note' is
displayed. This is the note recognized by the quantizer. The left pointing arrow shows the
status of the output gate. Next to it the 'output note' is shown. This is the note that is
mapped via the scale mapper and put out to CV-out as a voltage. There are dierent ways
input and output notes can be displayed. (see notations).
On the bottom of the main menu, you can see the name of the currently loaded scale.
You can access settings and tools via four sub-menus:
 INFO shows the status of each channel in more details and also displays the detected
frequency. It can also be accessed by pressing the BACK button form the main menu
 TOOLS contains various tools, such as VCO calibration, auto-tuning or clock generator.
 TUN (tune) contains functions dealing with tuning and scales
 CONF contains all other settings and congurations of µ Tune
If you have expanders installed the main menu will look dierent because the status of the
additional channels is shown. In the examples below we used dierent notation settings for the
channels: Channel 1 and 2 have notation setting 'decimal'. Channels 3,4,6, and 8 are set to
'semitone' and channels 5 and 6 are set to 'relative 1'. More info about the possible notation
display can be found in the chapter about notation settings.
Figure 5: Main menu with 4, 6 and 8 channels (using 1,2 and 3 expanders)
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2.2 INFO
Figure 6: Status and Tuner
The INFO screen shows the status of channels 1 and 2 in more detail. If you have more than
two channels by means of expanders, you can scroll to display those as well. Just as in the main
menu, you can see input note (upper left corner), output note (upper right corner), input and
output gate states (arrows) and the current scale on the bottom. Additionally the frequency
detected at the GATE-in input is shown. You can set the display mode of this frequency to
the following modes:
 Hz: shows the frequency in Hertz. In the example this mode is used for channel 1.
 Absolute pitch: Shows the frequency like a normal tuner (e.g. guitar tuner) would do.
You can see the closest detected note (e.g. C#) and the error in cents. If you however
load a dierent tuning it will use its notes as base for the calculation. So it's a fully
microtonal tuner. In the example this display mode is used for channel 2.
 Relative pitch: pretty much like absolute pitch, but shows the dierence from the ex-
pected pitch based on the current output note. This is very useful when tuning your
setup or when preparing a VCO for auto-tuning.
 BPM: Shows the detected frequency as 'beats per minute'. Useful for measuring clock
signals
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2.3 CONF
In the cong menu you can set conguration for inputs and outputs, midi
2.3.1 Channel conguration
Figure 7: Channel congs for channel 2 and for all channels at once
Each channel can be congured individually in the channel cong menu. You can select the
channel to edit with the 'Channel to edit' selector. Here, you can also select 'ALL' to congure
all channels at once.
µ Tune can detect whether an input is used and change the conguration accordingly. For each
of the four possible modes (cv and gate not plugged in, cv only plugged in, gate only plugged
in and both plugged in) you can congure the function of each input and output. This can be
done in a simple way which is sucient in most cases, or you can specify the behavior in full
detail.
Plug in detection can be used to automatically change your setup based on the plugged in
connections. For example: if no CV-input is connected the channel works as a midi to CV/gate
interface, but if you plug it in it quantizes and outputs an automatically generated trigger pulse.
The possibilities are almost endless here.
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Simple channel cong Here you can set conguration for all inputs and outputs. µ Tune
will copy these settings to the parameters in the Advanced Cong, overriding them if applicable.
The following input and output congurations are possible.
Figure 8: Simple cong menu
 CV-IN:
 "None": CV-in is not used
 "Pitch Map": CV-in is used as input for the quantizer
 "Transpose": CV-in is used to transpose an other channel. You can set the target
channel as well.
 "Shift": CV-in is used to shift the scale of an other channel. You can set the target
channel as well.
 "GlidSpeed": CV-in is used to set the glide speed of a specic channel.
 GATE-IN:
 "None": GATE-in is not used.
 "Gate": The quantizer runs in gated mode and will only quantize if the gate is on.
 "Trigger": The quantizer runs in triggered mode and will quantize once every time
the gate is turned on. Use the 'Trigger delay' parameter to set a delay between
detected gate and the actual quantizing. This can be used to compensate for
sequencers with a slowly rising CV output.
 "Glide SW": Can be used to turn glide of a specic channel on and o.
 "Rand Trig": Each time the gate is turned on, the output will be transposed
randomly.
 "Frequency": Use the gate input for frequency detection only.
 CV-OUT:
 Pitch: CV-OUT is used for pitch output from the quantizer or midi.
 "Velocity": CV-out is used to output midi velocity. You can dene which channel
should be the source of the velocity.
 "OVelo": CV-out is used to output midi o-velocity. You can dene which
channel should be the source of the o-velocity.
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 "Aftertch": CV-out is used to output midi aftertouch. You can dene which
channel should be the source of the aftertouch.
 "ChanPres": CV-out is used to output midi channel pressure. You can dene which
channel should be the source of the channel pressure.
 "Controllr": CV-out is used for midi controller control. The midi controller number
used can be found in the midi controller sheet.
 GATE-OUT:
 "None": GATE-out is disabled.
 "Midi Gate": GATE-out is used to output the midi gate
 "Midi Clk": GATE-out is used to output midi clock. You can also set the divider
used here.
 "Midi S/S": GATE-out is used to output midi start and stop signals.
 "Clock": GATE-out is used to output clock from the internal clock generator. You
can also set the divider used here.
 "Start/Stp": GATE-out is used to output the start/stop signal from the internal
clock generator.
 "Gate Pass": The input gate is passed directly to the output. This can also be
used to invert a gate (by setting the gate polarity to inverted), or convert a normal
gate into a switch-trigger gate (by setting the gate polarity to switch trigger). See
gate polarity parameter below.
 "Auto trig": Each new note detected by the quantizer generates a pulse at the
gate output. The pulse length can be set here as well.
Advanced channel cong Advanced channel cong contains all the parameters of simple
channel cong, but they are adjustable for each of the four possible congurations individually:
 Both unplugged: GATE-in and CV-in are both unplugged
 CV-IN plugged in: Only CV-in is plugged in, GATE-in is unplugged
 GATE-IN plugged in: Only GATE-in is plugged in, CV-in is unplugged
 Both plugged in:; Both GATE-in and CV-in are plugged in
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Other channel parameters Further channel parameters are adjustable
 Notation: Set the displayed notation of the current note for this channel. (see notations
chapter).
 Gate-out mode:
 Normal: normal gate operation: Gate o is 0V, Gate on is 5V/12V
 Inverted: inverted gate operation: Gate on is 0V, Gate o is 5V/12V
 Switch trigger: Gate o is an open connection, Gate on is shorted to GND
 Switch trigger inverted: Gate on is an open connection, Gate o is shorted to GND
 CV-in NOTES/V: The number of notes per Volt the quantizer detects at the input.
Usually this number is 12 because of the 1V/octave standard, but for scales with a
length dierent than 12 it may make sense to change this. If you have a quartertone
scale for example you can set this to 24 and still maintain 1V/Octave. You can also
set this parameter to AUTO and the number of notes in your scale will be used. A
higher number of notes will however result in a reduced noise rejection. Depending on
the voltage source this might lead to incorrectly detected notes.
 V/Hz: Set the number of octaves for V/Hz mode, or turn it o (default). (See v/Hz
chapter for more information.)
 V/Hz Oset: Oset parameter for V/Hz mode, see V/Hz chapter.
 Glide time: Set the glide time for this channel.
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2.3.2 Midi conguration
The Midi conguration settings contain parameters for midi input (Midi-to-CV), midi output
(CV-to-MIDI), as well as conguration pages for the midi router.
Figure 9: Midi cong and Midi input cong menu
Input Cong The midi input cong contains settings for µ Tune's midi input. Each µ Tune-
channel (One set of CV-in, GATE-in,...) can have an individual midi input channel assigned
to. µ Tune-channels with the same midi channel are grouped into polyphonic midi instruments
automatically. This allows you to dene multiple polyphonic or monophonic 'synths'.
Further more two global parameters can be dened here:
 Assign: Is the voice assigner mode for the polyphonic groups:
 "Mono/Unison": Treats the whole group as a monophonic synthesizer with au-
tomatic note priority. All channels in the group will output the same CV and
gate.
 "Cycle": The assigner will cycle through the available voices. Playing the same
note multiple times will result in another voice playing it every time. If all voices
are used, voice stealing will 'steal' the least recently used voice. This scheme is
also used by the Korg Polysix synthesizer.
 "Cycle Unique": The assigner will cycle through the available voices, unless the
specic note has been assigned to one of the voices before. Playing the same note
multiple times will result in the same voice playing it. Playing dierent notes will
result in cycling through the available voices. If all voices are used, voice stealing
will 'steal' the least recently used voice. This scheme is used by the Roland Juno
synthesizers.
 "Stacking": The stacking mode is very useful if your voices have dierent sounds.
If only one note is on, it will always be played by the rst voice in the group. If a
second note is received, the assigner will use the second voice and so on. It will
stack the voices on top of each other. For example: the rst voice in your setup
has a lower lter setting than the rest. If you now play chords by playing the lowest
note rst, it will always be assigned to the 'bass voice'.
 "Random" assigns the new notes to the voices randomly.
 In bender range: Range of the pitch bend input in semitones. 1 means the full range
of the midi pitch bend message is assigned to ±1 semitone, 12 means ±12 semitone. 0
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means pitch bend input is turned o. This is needed because the midi standard does
not dene the bender range and it can be chosen freely by both the midi sender and
receiver.
Output Cong For each µ Tune-channel you can set:
 "Midi out chan: The midi output channel
 "Midi out chan: An oset added to the midi note when sending.
 Mode: The midi output mode of this channel
 "O": No midi is sent
 "Note": The channel outputs midi notes
 "Controller": The channel outputs midi CC for the event detected at the gate and
CV inputs. The midi CC numbers used can be found in the midi out sheet at the
end of this manual.
Midi Routing A exible midi router and merger lets you route midi note and real-time
messages independently.
 Note routing sets the routing paths for all non-midi real time messages such as: Note
messages, controller messages, pitch bend, aftertouch, etc. These messages can be
duplicated and merged.
 Clock routing sets the routing paths for midi clock, midi start, midi stop and continue.
These messages can be duplicated, but not merged due to their nature.
 Sysex routing denes routing for midi sysex messages. These can also not be merged,
but can be duplicated.
Figure 10: Midi Routing
In the routing menu you can see three midi sources on the top: USB (USB midi input), DIN
(DIN midi input) and CV (midi from the CV to midi converter). On the right are three midi
targets: USB (USB midi out), DIN (DIN midi out) and CV ( µ Tune's voice assigner).
15

You can use the navigation knob and the enter button to turn routing paths on and o. For
example in the picture USB-in and CV-in are merged and routed to USB-out. DIN-in and
CV-in are merged and routed to DIN-out. And USB-in is routed to the µ Tune voice assigner.
Since merging is not possible with clock and sysex signals, for clock and sysex routing only
one source per target is possible.
For targets DIN and USB you can also send microtonal midi. To activate this, press the
ENTER button again to display the µ alongside the arrow. This means that this particular
path is now re-tuned using the current scale. There are several modes mircotonal midi can be
sent:
 Sysex tuning sends microtonal midi using the 'midi realtime tuning' sysex messages
dened in the midi standard. This allows polyphonic tuning but is a mode not all
synthesiers understand
 Pitch bend tuning uses midi pitch bend to tune the notes as needed. This has the
disadvantage that it only works properly monophonically, or if each channel uses a
dierent midi channel. Because the pitch bend resolution is not dened in the midi
standard you can dene its range between ± 1 and ± 12 seminotes.
These settings can be made for targets USB and DIN independently using the USB tuning
and DIN tuning settings in the midi menu.
2.3.3 MISC menu
The misc menu contains the following sub-pages:
 About: info about the module and its contributors
 Channels: You can use this to temporarily override the number of channels. This for
example allows you to only use channels 1 and 2 even though you have an expander
connected.
 Expert settings contain settings not typically needed by the user.
2.3.4 Firmware reset
Select this to set all parameters to their default values.
16

2.4 TUN
The TUN menu contains all functionallity needed to work with alternative scales and tuning.
2.4.1 Load a scale
Figure 11: File browser
To load a scale or tuning, select 'Load scale'. This will open the le browser showing the
contents of the SD card. Directories are marked with a 'folder' symbol, scale les with a
'scale le' symbol. In the upper right corner you can see the number of entries in the current
directory.
By using the navigation knob you can scroll through the directory contents. When a scale le
is selected, the bottom of the screen will show the name of the scale. You can load a scale by
pressing ENTER. µ Tune reads and writes the Scala .scl format directly.
When selecting a directory, you can enter it by pressing ENTER. The ... entry brings you up
one directory.
Due to limitations of the µ Tune hardware and the FAT le system, the items are not sorted
alphabetically, but roughly in the order of their creation. Additionally directory access becomes
slower, the further down you scroll in a directory. We therefore recommend to organize scales
in a tree structure with not more than about 50 scale les per directory.
After loading a scale, press the BACK button to get back to the main menu.
2.4.2 Save a scale
Press Save scale to save your current scale. You can now chose if you want to save the scale
using a new le name (Save as), save the scale using the current le name (Save) or if would
like to rst chose the directory to save the scale (Choose directory). If you decide to enter a
new le name, you will be presented with the le name dialog. Use the navigation knob to
select the next character of the le name. Press enter to use this character. If you want to
delete the last character press DEL, for upper case letters press SHIFT. When you are nished
entering the le name, press OK. To cancel press the BACK button.
17

2.4.3 Scale editor
The built in editor lets you create and edit scales without the need of an additional computer.
Figure 12: Scale editor
2.4.4 Navigation in scale editor
If your cursor is above a note number on the left and blinking, you can use the navigation
knob to scroll up or down. Press enter and the cursor will stop blinking, indicating that you
have selected a line to edit. You can now use the navigation knob to select parameters. Press
enter on a parameter to edit it and press it again to resume selecting other parameters.
2.4.5 Edit scales
In the rst line you can set the number of notes in the scale, change its name (NAME) and
create a new equal tempered scale (NEW). In order to create an equal tempered scale, set the
number of notes to the desired value, set the repeating interval (see below) and press NEW.
A new equal tempered scale will be created and the scale name adjusted accordingly. For
example setting the note number to 12 and the repeating interval to 2/1 will create a 12TET
scale, setting the note number to 13 and the repeating interval to 3/1 will create the equal
tempered Bohlen-Pierce scale.
The other lines starting with 01, 02, etc show the notes of the scale. Each note is displayed
in two lines. From left to right the rst line shows the note number (03), an active indicator
(little arrow), the note pitch in cents and note pitch as fraction. The second line contains the
name of the interval if it is a known one.
1
You can edit each of these parameters:
 The active indicator arrow can be highlighted and toggled to deactivate a note in scale,
creating a voltage quantizer within your tuning system or temperament. For example,
by deactivating C#, E, F#, A and B in any standard 12Tone temperament, you have
a Natural Minor quantizer in eect. (also see tuning vs. scale denition at the end of
this manual)
 The pitch in cents can be edited by selecting a digit and using the navigation knob
to adjust the value. Usually this is a positive number, but some exotic scales contain
negative pitches, so negative cents are possible.
18

 You can also set the pitch as a fraction. In this representation 1/1 is unison, or 0 Cents,
2/1 is an octave, 3/2 is a perfect fth. Changing the fractional value will adjust the
cents accordingly. If it is a known interval, its name will be displayed in the second line.
Fractions with a numerator larger than the denominator will create positive cent values,
fractions with a numerator smaller then the denominator will create negative cents
 You can also move the cursor to the second line and chose your pitch from a list of
intervals. The fractional and cent values will be adjusted accordingly. If no known
interval is selected the second line shows nothing, but scrolling starts from the interval
closest to the current pitch. So for example if you have a pitch value of 300 cents,
you can move the cursor to the second line and starts scrolling. Scrolling will show you
Persian wosta (302.8 cent), Wide augmented 2nd (296.1 cent) , and so on.
1
µ Tune is programmed to recognize all tuning ratios that have known named
intervals: even the very rare ones. This is thanks to a list generously provided by
Manuel Op de Coul, creator of Scala).
19

2.4.6 Scale mapping
In the keyboard mapping menu you can specify how an incoming note number (be it from a
midi keyboard or quantized CV-in input) is mapped to the scale.
Figure 13: Scale mapping
 Mdl note: The middle note species the center if the scale. When playing this note the
pitch will be constant no matter which scale you load or how many notes the scale has.
µ Tune displays this note in two dierent notations (number and seminotes)
 Mdl volt: The voltage corresponding to the Middle note. This voltage will be at the
output if you play the middle note, no matter which scale is loaded. µ Tune displays the
voltage in 1/12V steps.
 Ref note: The reference note for which the Reference Frequency is given.
 Ref pitch: Reference pitch, frequency of the Reference Note. This is used for pitch
detection (See INFO) and auto-tuning.
 'Open' and 'Save' access the le browser and let you open and save scale mappings
using the SD card.
More about scale mapping can be found in chapter Scale mapping in the HOW-TO section.
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