Mutable Instruments Yarns User Manual

Mutable Instruments | Yarns

Yarns is a MIDI to CV interface. Thanks to its flexible architecture, it can manage up to 4 voices of
polyphony or up to 4 individual channels. Yarns embeds an arpeggiator, a note sequencer, and an
euclidean pattern generator.

Yarns is designed for Eurorack synthesizer systems and occupies 12 HP of space. It requires a -12V /
+12V supply (2x5 connector), consuming 2mA from the -12V rail and 60mA from the +12V rail. The red
stripe of the ribbon cable must be oriented on the same side as the “Red stripe” marking on the printed
circuit board.

This device complies with part 15 of the FCC Rules. Operation is subject to the following
two conditions: (1) This device may not cause harmful interference, and (2) this device must
accept any interference received, including interference that may cause undesired
operation.

This device meets the requirements of the following standards: EN55032, EN55103-2,
EN61000-3-2, EN61000-3-3, EN62311.

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Mutable Instruments | Yarns

At the right of Yarns’ display is an encoder which is used to increment/decrement values and scroll
through options. The typical way of modifying Yarns’ settings is to scroll through the list of settings, click
the encoder to select one of them, then rotate the encoder to increment/decrement the value of setting,
and click again once you are done. Yarns’ display is small, so settings names are abbreviated into 2
letters code (VR = “Vibrato range”). To ease navigation, the unabbreviated form of each setting or value
scrolls on the display after a few seconds of inactivity.

Below the display are 3 buttons, whose primary functions are to control the sequencer:

REC starts and ends step-by-step recording.
START/STOP starts and stops the sequencer.
TAP acts as a tap-tempo.

In addition:

In recording mode, START/STOP and TAP enter a tie step (extends the duration of the previous note onto
this step) or a rest (blank step) in the sequence.

Holding the START/STOP button for a few moments latches the arpeggiator (if it is running), or starts and
hold a note. More on that in the Latch and keyboard-free operation section!

Three important concepts are used throughout this documentation: voice, part, and layout.

You can think of a voice as a group of CV and Gate outputs working together to convey information about
a single note of music. A traditional monophonic MIDI interface manages only one voice. In its simplest
expression, a voice would need only one CV output (to output the note frequency information), and one
Gate output (to output the note on/off status) - though additional CV and Gate signals can be produced,
for example an extra trigger or a velocity CV.

A part is a group of voices responding to the same MIDI channel. Whenever a note is played on this MIDI
channel, it will be dispatched to one of the voices in the group.

Yarns can handle up to 4 parts, and there are enough CV/Gate outputs for 4 voices. This means that there
are many different ways of getting these to work together! Each of these configurations are called Layouts.

Yarns provides the following layouts:

1M. Monophonic. Yarns offers a single voice of CV/Gate conversion.
2M. Dual monophonic. Yarns provides two independent monophonic voices. The voices are independent in

the sense that they can play different sequences, respond to different MIDI channels, etc.

4M. Quad monophonic. Yarns provides four independent monophonic voices.
2P. Duophonic. Yarns provides a single part made of two voices. The incoming notes are dispatched to these

two voices.

4P. Quadraphonic. Yarns provides a single part made of four voices. The incoming notes are dispatched to

these four voices.

2>. Duophonic with polychaining. Yarns provides a single part made of two voices. However, only the first

voice is handled by Yarns’ CV/Gate outputs. The second voice is simply forwarded as MIDI Note on/off
messages the MIDI out. This allows “ping-pong” play between the modules connected to Yarns and another
MIDI instrument. This can also be used to chain several instances of Yarns to get more CV outputs.

4> and 8>. Quadraphonic and octophonic with polychaining. Yarns provides a single part made of 4 or 8

voices. Only the first half of the voices are handled by Yarns’ CV/Gate outputs. Notes allocated to the other
voices are forwarded to the MIDI output.

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Mutable Instruments | Yarns

4T. Quad trigger mode. This layout is optimized for controlling percussion patches (for example from MIDI

drum pads, or from a MIDI drum sequencer). It offers 4 parts, each of them listening to a single MIDI note. No
control-voltage is emitted - just a trigger, freeing some outputs to emit additional gate and clock signals.

The layout can be changed by selecting the LA(YOUT) setting, clicking the encoder, selecting a layout in
the list, and clicking the encoder to confirm.

Yarns offers 4 CV outputs and 4 Gate outputs. What do they correspond to? It all depends on the selected
layout!

In single-voice layouts (1M, and 2>), the 4 CV outputs are assigned to:

V/Oct note
Velocity
Modulation wheel
Assignable (aftertouch, expression pedal, breath controller, LFO… More on that in the “Layout and MIDI

options”)

The 4 gate/trigger outputs are assigned to:

Gate (a signal at a +5V level whenever a key is pressed and held)
Trigger (short pulse at the beginning of each note)
Clock
Start/bar trigger (more on that in the “Clock and tempo” section).

In dual-voice layouts (2M, 2P and 4>), the 4 CV outputs are assigned to:

Voice 1 V/Oct note
Voice 2 V/Oct note
Modulation wheel
Assignable

The 4 gate/trigger outputs are assigned to:

Voice 1 gate
Voice 2 gate
Clock
Start/bar trigger

In four-voice layouts (4M, 4P and 8>), the 4 CV outputs are assigned to each voice’s V/Oct note. The 4
gate/trigger outputs are assigned to each voice’s gate.

In the quad trigger layout (4T) mode, which is optimized for percussions patches, the 4 CV outputs emit
excitation pulses. In their simplest form, the excitation pulses are the +5V trigger you’ve learnt to love - but
options are provided to stretch them in time, shape them like envelopes, or even scale them with velocity!

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Mutable Instruments | Yarns

This produces signals particularly useful for “pinging” filters, low-pass gates, or tuned delay lines.

The 4 gate/trigger outputs are assigned to:

Voice 1’s trigger with routing controlled by voice 2’s gate.
Voice 1’s trigger with routing controlled by voice 2’s gate.
Clock
Start/bar trigger

A word about this mysterious voice 1⁄2 routing affair… Here is how it works: if voice 2 is off when a trigger
arrives on voice 1, it’ll come out of the trigger output 1. If voice 2 is on when a trigger arrives on voice 1,

it’ll come out of the trigger output 2. This feature can be used creatively for getting the same drum sound
(voice 1) played differently depending on whether it is played alongside another drum sound (voice 2).
Don’t panic though - the regular triggers are of course available on the 4 CV outputs!

This section lists the different settings related to layout and MIDI reception.

LA(YOUT): Voices/parts layout. The different options have been exposed in the “Yarns’ architecture”

section.

PA(RT): Active part. Many settings - such as the MIDI channel, arpeggiator pattern, etc. - can be set to

different values for each part. When a layout is made of several parts (2M, 4M, 4T), this setting is used to
select the part to modify. This option is not visible in mono-timbral layouts.

CH(ANNEL): MIDI reception channel. A part can be made to respond to all MIDI channels (omni mode).

NO(TE): MIDI reception note. This option is only shown with the 4T layout, in which each part is triggered

by a different MIDI note.

>> (OUTPUT MIDI MODE): MIDI output routing. When set to OFF, none of the events received by this part

are forwarded to the MIDI out. When set to THRU, all events received by this part are forwarded to the
MIDI out without any processing. Finally, when set to AR(P/SEQ), all the notes generated by this part’s
arpeggiator/sequencer are sent to the MIDI OUT.

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