µClouds SE
Eurorack Module
TD-UCSE-C
Designed by Daniel & Michael Gilbert of Tall Dog
Electronics in Western Massachusettstall-dog.com | uclouds-se.com
Based on the Clouds module designed by Émilie Gilletof Mutable Instruments
mutable-instruments.net
Partially manufactured by Worthington Assembly via
CircuitHub in South Deerfield, MA
worthingtonassembly.com
circuithub.com
Partially manufactured by PCBWay in Hangzhou, China
pcbway.com
Assembled at Rust Temple in Easthampton, MA
rusttemple.today

cba
Licensed under Creative Commons
Attribution-ShareAlike 4.0 International
creativecommons.org/licenses/by-sa/4.0
Source materials are available on GitHub
github.com/loglow/uClouds_SE

Contents

2

About................................................................................................ 3
Included Parts............................................................................... 3
History.............................................................................................. 4
Warranty......................................................................................... 5
Granular Synthesis..................................................................... 6
Front Panel..................................................................................... 8
Blend Parameters......................................................................11
Audio Quality...............................................................................13
Saving & Loading Buffers	������������������������������������������������������14
Tips & Tricks.................................................................................15
Calibration....................................................................................16
Alternate Modes.........................................................................17
Firmware Warnings..................................................................18
Firmware Update.......................................................................19
Serial Programming.................................................................20
JTAG Programming...................................................................21
Documentation..........................................................................22
CC BY-SA 4.0.................................................................................23
Support..........................................................................................24
Who We Are..................................................................................24

About3

Clouds is a granular audio processor that creates
textures and soundscapes by combining multiple
overlapping, delayed, transposed and enveloped
segments of sound taken from a recording buffer.
This redesigned µClouds SE (Special Edition) is a newrevision of Clouds that miniaturizes the module from18HP to 8HP and redesigns its front panel layout.
µClouds SE remains fully compatible with future
upstream Clouds firmware upgrades and any otheralternate firmwares that are compliant with thestandard Clouds design.

Included PartsµClouds SE includes a standard 16-pin to 10-pin
Eurorack power cable and two sets of mounting screws
for racks/enclosures with either M2.5 or M3 threads.
The TD-UCSE-C/B variant has a matte black front panel
with gold markings made from FR-4 (glass-reinforced
epoxy laminate) material. The included mounting
screws are black.
The TD-UCSE-C/S variant has a satin silver front panel
with black markings made from anodized aluminummaterial via the Metalphoto process. The included
mounting screws are silver.

History
The original Clouds (mutable-instruments.net/
modules/clouds) was designed by Émilie Gillet of
Mutable Instruments (mutable-instruments.net/
about) under a CC BY-SA 3.0 (creativecommons.org/
licenses/by-sa/3.0) license. Clouds is available as a18HP Eurorack module.
Clouds differs from other granular Eurorack modules
in that it focuses on the real-time processing of audio
sources from your modular system itself, rather thanthe playback of pre-recorded samples from a storage
device. It rewards the freezing, fragmentation anddissolution of the unexpected instant, rather than the
careful planning of what might very well not come.
Source: github.com/pichenettes/eurorack4

Warranty

5This product is covered under warranty for one year
following the date of purchase as indicated on theoriginal sales receipt. This warranty covers any defectin the manufacturing of this product. This warranty
does not cover any damage or malfunction caused
by incorrect use—such as, but not limited to, power
cables connected backwards, excessive voltage levels,
exposure to extreme temperature or moisture levels,
physical damage due to impact, or any aftermarket
physical or electrical modifications or repairs.
This warranty covers either repair or replacement,
at our sole discretion. This repair or replacement issubject to verification of the defect or malfunction andproof of purchase as confirmed by showing the model
number on an original dated sales receipt. Shippingand handling fees are to be paid for by the customer.
Please contact support@tall-dog.com for a return
authorization prior to shipping anything to us. Please
understand that we will not be able to service units
under warranty that have been modified or previously
repaired by the customer or a third party.

Granular Synthesis

6

Clouds continuously records the incoming audio intoa short amount of sample memory. While recording
time can reach up to 8 seconds by reducing the audio
quality setting, don’t think of this as tape—think of it
as a space, a room. Using this recorded audio data, themodule synthesizes a sonic texture by playing backshort (overlapping) segments of audio (also known as
grains) extracted from it.
Clouds allows you to control:●● From which part of the buffer the grains are taken.
●● How long the grains are.
●● At which speed/pitch the grains are replayed.
●● How much overlap there is between the grains(density).
●● Whether the distribution of grains in time is constantor random.
●● Which envelope curve is applied to the grains, thus
giving the impression of a rough or smooth texture.
In addition, to create textures with a blurry feel, adiffuser (a network of all-pass filters, like reverb
without tail) can be applied.

Granular Synthesis Cont’d

7

The module plays grains continuously, at a rate
determined by the DENS (density) and SIZE settings. A
trigger input (TRIG) is also present to explicitly instruct
the module to start the playback of a new grain. The
maximum number of concurrent grains is quite large—
between 40 and 60. This specificity brings Clouds
closer to the roots of granular synthesis, and allows thesynthesis of varied textures even from basic waveforms.
There are many more dimensions to granular synthesisthan keeping a playback pointer moving through a SDcard sample!
It is possible, at any time, to FREEZE the audio bufferfrom which the grains are taken. In this case, theincoming audio is no longer recorded. In a sense,
Clouds is the exact opposite of a sampler: by default,
the module always samples the audio it receives,
except when it is in the frozen state.

Front Panel

8

IN L and IN R — Stereo audio input jacks. When nopatch cable is inserted in the right channel input, this
input will receive the signal from the left channel.
IN GAIN — Audio input gain adjustment knob, with arange from -18 dB to +6 dB.
TRIGGER — Generates a single grain. By moving the
DENS knob to 12 o’clock, and sending a trigger to this
input jack, Clouds can be controlled like a microsample player. An LFO or clock divider (or even apressure plate) can thus be used to sow grains at therate of your choice.
FREEZE — This button stops the recording of incoming
audio. Granularization is now performed on the last
few seconds of audio kept in memory in the module.
When the FREEZE input jack’s gate signal is high, therecording of incoming audio stops, just as latching the
FREEZE button would do.

Front Panel Cont’d

9

All CV inputs are calibrated for a range of ±5V. Voltages
outside of this range are tolerated, but will be clamped
to ±5V.
POS — Grain position adjustment knob and CV input.
Selects from which part of the recording buffer theaudio grains are played. Turn the knob clockwise totravel back in time.
DENS — Grain density adjustment knob and CV input.
At 12 o’clock, no grains are generated. Turn clockwise
and grains will be sown randomly, counter-clockwise
and they will be played at a constant rate. The further
you turn, the higher the overlap between grains.
SIZE — Grain size adjustment knob and CV input.
TEXT — Grain texture adjustment knob and CV input.
Morphs through various shapes of grain envelopes:
square (boxcar), triangle, and then Hann window. Past
2 o’clock, activates a diffuser which smears transients.
PITCH — Grain pitch (transposition) adjustment knob
and CV input with V/octave response. At 12 o’clock, thebuffer is played at its original frequency.
BLEND — The CV input can control one of the following
functions depending on the active blending parameter:
dry/wet balance, grain stereo spread, feedback amountand reverb amount. The multi-function BLEND knob isdescribed in the Blend Parameters section on page 11.

Front Panel Cont’d

10

MODE — This button selects which of the blending
parameters is controlled by the BLEND knob and CV
input, or selects one of the four audio quality settings.
MEMORY — This button is described in the Saving &Loading Buffers section on page 14.
Indicator LEDs — These work as an input VU meter.
When FREEZE is active, they monitor the output level.
Soft-clipping occurs when the last LED is on. They canalso indicate the quality setting (red), the function
assigned to the BLEND knob (green), or the values ofthe four blending parameters (multicolor).
L and R — Stereo audio output jacks.

Blend Parameters

11

The BLEND knob can control one of four settings:●● Dry/wet balance●● Stereo spread (amount of random panning/balance
applied to the grains)●● Feedback amount●● Reverberation amountTo select which parameter is controlled by the BLEND
knob and its associated CV input, press the MODE
button. The current parameter is temporarily indicatedby a green LED.
When turning the BLEND knob, the color of the four
status LEDs temporarily shows the value of the four
blending parameters (from off, when the parameter is
set to its minimum value, to green, amber, and then red
for its maximum value).
At times, the position of the knob may not match thevalue of a parameter. This is a drawback inherent tomulti-function knobs. When this happens, turning
the BLEND knob clockwise (or counterclockwise) willcause a small increase (or decrease) in the value of theparameter, and turning it further will cause a largerchange, until the value progressively catches up withthe knob’s position.

Blend Parameters Cont’d

12

There are a few things worth knowing about thesesettings:●● All settings are automatically saved, and will be
restored the next time the module is powered on.
●● Strange things happen when FREEZE is enabled.
Because feedback/layering can no longer occur inthe recording buffer (which is frozen) the output
signal is routed through delays and all-pass filters,
letting the feedback build-up in this extra recording
space. This gives the sound a reverb-like nature.

Audio Quality

13

Hold the MODE button for one second, then press it
repeatedly to choose a recording quality. The current
quality setting is indicated by a red LED:
Rate

Resolution

Channels

Buffer1

32 kHz16-bitStereo1 sec

2

32 kHz16-bit

Mono

2 sec

3

16 kHz8-bit μ-law

Stereo4 sec

416 kHz8-bit μ-law

Mono

5 sec

Note that Clouds uses a lovely flavor of 8-bit calledµ-law companding which sounds like a cassette or a
Fairlight, but with less hiss and more distortion.

Saving & Loading Buffers

14

Up to 4 frozen audio buffers can be saved and reloaded.
Along with the audio data itself, the quality settings andthe processing mode are saved with it.
To save the recording buffer in permanent memory:
1. Hold the MEMORY button for one second.
2. Press the MODE button repeatedly to select one of
the 4 memory slots. The selected slot is indicated bya blinking red LED.
3. Press the MEMORY button to confirm.
To load a recording buffer from permanent memory:
1. Press the MEMORY button.
2. Press the MODE button repeatedly to select one of
the 4 memory slots. The selected slot is indicated bya blinking green LED.
3. Press the MEMORY button to confirm.
If you press the MEMORY button by mistake, don’t
press any button for a few seconds and the module will
return to its normal state.

Tips & Tricks

15●● If you need a noise source to randomize grain
position or pitch, you can reuse one of the audio
outputs. It’s not white noise, but it’s random
enough.
●● Scratch and caress a sound by using a contact
microphone or a touch strip to trigger grains, thenmodify the playback position via POS.
●● Very dense clouds sound the best when at least
one parameter (PITCH or POS) receives random
modulations. Otherwise, the many identical echoes
created by the repeating grains will sound like a very
resonant feedback comb filter.
●● Raw material like sawtooth or sine waves sound very
good, especially with heavy random modulation. A
fun exercise is to recreate the classic THX sound witha random source and a VCA.
●● Send a very fast sequence of 3 or 4 notes to the
PITCH input, so that each randomly sown grain
picks one of the notes. The result is a chord!
●● Experiment with capturing many small fragmentsof sound by sending short pulses to FREEZE while
a complex patch is being played through the audio
input!

Calibration

16

The module is factory-calibrated using precisionvoltage sources. Follow this procedure only if you wantto compensate for inaccuracies in your CV sources, or if
your module has lost its calibration settings following a
fault or the installation of alternative firmware.
To calibrate the unit:
1. Disconnect all CV inputs.
2. Connect the note CV output of a well-calibrated
keyboard interface or MIDI-CV converter to the
PITCH input jack.
3. Press and hold the MEMORY button, and while
holding it, press the MODE button. The first two
LEDs will blink orange. Release the buttons.
4. Play a C2 note, or send a 1V signal from your CV
source.
5. Press the MEMORY button. All four LEDs will blinkorange.
6. Play a C4 note, or send a 3V signal from your CV
source.
7. Press the MEMORY button.
Calibration is complete.

Alternate Modes

17

Early in its development, Clouds tried to be manydifferent things. This experimental code is still available
in the module. Press the MODE button for 5 seconds
until one of the LEDs glows orange, then repeatedlypress the button to select one of the following
functions:
1. Granular processor (default mode)
2. Pitch shifter/time-stretcher
3. Looping delay
4. Spectral processor
These features are experimental, undocumented,
and the knobs might be reassigned to functions very
different from what is printed on the panel!

Firmware Warnings

18

Before starting the audio firmware update procedure,please double-check the following:●● Make sure that no additional sound (such as email
notification sounds, background music, etc.) fromyour computer will be played during the procedure.
●● Make sure that your speakers/monitors are muted
or not connected to your audio interface—the noises
emitted during the procedure are aggressive andcan harm your hearing.
●● On non-studio audio equipment (for example theline output from a desktop computer), you might
have to turn up the volume to the maximum.

Firmware Update

19

Unplug all inputs/outputs from the module. Connect
the output of your audio interface or sound card to the
IN L input jack. Power on your modular system while
holding the FREEZE button, then release. The FREEZE
LED should blink.
When you are all set, play the firmware update file
into the module. While the module receives data, thebar graph will show the signal level. Signal reception
is optimal when two or three LEDs are lit. You can use
the IN GAIN knob to boost or reduce the gain. Whenthe end of the audio file is reached, the module willautomatically restart. If it doesn’t restart, please retry
the procedure.
If the signal level is too weak, the LEDs will blink red.
Press the FREEZE button and retry with a higher gain.
If this doesn’t help, try the procedure from a different
computer or audio interface, and make sure that noother equipment (such as an equalizer or FX processor)
is inserted in the signal chain.

Serial Programming

20

The module can also be programmed using a serial
data connection. This is most easily accomplished byusing a USB-to-serial chip such as the popular FT232R
which can be found in many standalone breakout
boards and cables, including the FTDI TTL-232R-3V3 aswell as various equivalents from Adafruit, SparkFun,
and others. Data signals should be at 3.3V levels.
The serial connection should be hooked up to thewhite shrouded 6-pin header labeled FTDI (H6) on themodule’s PCB. This is a JST-XH header that works very
well with the 0.1″ pitch female connectors that are
frequently found on these cables. Only pins 1 (GND),
4 (RX), and 5 (TX) are used, and the location of pin 1 isclosest to the top of the board. Power must be supplied
separately via a Eurorack power cable connected to the
POWER (H7) header.
To prepare the processor for serial programming:
1. Power-on the module.
2. Press and hold both the BOOT (S1) and RESET (S2)buttons at the same time.
3. Release the RESET button.
4. Wait a moment, then release the BOOT button.
The processor is now ready to be programmed.

JTAG Programming

21

The module can also be programmed using a JTAG
programmer connected to the black shrouded header
labeled JTAG (H5) on the module’s PCB. Power mustbe supplied separately via a Eurorack power cableconnected to the POWER (H7) header.
An example of this kind of programmer is the Olimex
ARM-USB-OCD. Their ARM-JTAG-20-10 adapter is also
necessary in order to accommodate the module’s
miniature 0.05″ pitch 10-pin header.
No additional steps are necessary to prepare themodule for programming via this method.
If you are interested in serial or JTAG programming,
please explore the Vagrant environment for Mutable
Instruments modules hacking which can be found at
github.com/pichenettes/mutable-dev-environment
Other programming resources can be found at forum.
mutable-instruments.net/t/4336 (Mac Tutorial: How
to compile and upload the firmware of MIs eurorack
modules) and at medium.com/music-thing-modularnotes/a08173cec317 (How to get started writing yourown firmware for Mutable Instruments Clouds).

Documentation

22

Much of the information in this manual was created by
Émilie Gillet of Mutable Instruments and released under
the CC BY-SA 3.0 license.
Modifications and additions to this material werecreated by Tall Dog and released under the compatible
CC BY-SA 4.0 license.
For an overview of the implications and terms of theselicenses, please read the following page.

CC BY-SA 4.0

23

This is a human-readable summary of (and not a
substitute for) the license, which can be found at
creativecommons.org/licenses/by-sa/4.0/legalcode

You are free to:●● Share — copy and redistribute the material in any
medium or format.
●● Adapt — remix, transform, and build upon thematerial for any purpose, even commercially.

Under the following terms:●● Attribution — You must give appropriate credit,
provide a link to the license, and indicate if changes
were made. You may do so in any reasonable
manner, but not in any way that suggests thelicensor endorses you or your use.
●● ShareAlike — If you remix, transform, or build upon
the material, you must distribute your contributions
under the same license as the original.
●● No additional restrictions — You may not apply
legal terms or technological measures that legally
restrict others from doing anything the license
permits.

Support

24

For all support inquiries, please send an email tosupport@tall-dog.com

Who We Are
Tall Dog Electronics is located in the Pioneer Valley
region of Western Massachusetts. Tall Dog has primarily
focused on producing a variety of breakout boards for
the Teensy microprocessor development platform andconducts the majority of its business via the Tindie
marketplace. Tall Dog released their first Eurorack
module, µBraids SE, in late 2017.
Michael Gilbert is a composer, recording artist, andteacher of electronic music, for over 40 years. Hismusic is a creative mix of electronic, jazz, world, andcontemporary classical idioms, and is available on 9
albums of original work as Michael William Gilbert. The
music has featured Adam Holzman, Mark Walker, Peter
Kaukonen, David Moss, and Tony Vacca. He has also
designed and built electronic music equipment, using
it in his own studio and making it available to othermusicians.
Daniel Gilbert is a designer and engineer with abackground in film, photography, and animation. After
graduating from Hampshire College he spent the next
several years working in the Los Angeles film industry.
He now resides in Easthampton, Massachusetts, where
he designs, builds, and distributes Tall Dog products.

µClouds SE User Manual
Revised 2019-04-03
Documentation CC BY-SA 4.0