Moog Little Phatty User Manual
Table of Contents
Bob Moog Tribute Edition
FORWARD from Mike Adams .................................. 4
THE BASICS
How to use this Manual ....................................... 5
Setup and Connections ........................................ 5
Overview and Features ........................................ 7
Signal Flow .................................................................... 9
Basic Operation ......................................................... 10
THE COMPONENTS
A. Oscillator Section ................................................ 11
B. Filter Section ........................................................... 13
C. Envelope Generators Section ..................... 15
D. Modulation Section ........................................... 17
E. Output Section ..................................................... 18
F. Keyboard & LH Controllers ........................... 19
G. Input/Output Panel ............................................ 20
H. Interface Panel ...................................................... 21
THE USER INTERFACE
Preset Mode .......................................................................... 23
Master Mode ......................................................................... 25
A. Menus ........................................................................ 25
B. System Utilities ..................................................... 29
C. System Exclusive ................................................. 30
Receiving SysEx Data ........................................................ 31
Performance Sets ................................................................ 32
How the LP handles MIDI ............................................. 34
APPENDICES
A – Tutorial ............................................................................. 35
B – MIDI Implementation .............................................. 40
C – Service & Support Information ........................ 41
D – Caring for the Little Phattty ............................... 41
E – Using the CP-251 with the Little Phatty ...... 42
F – Speci cations ................................................................ 44
GLOSSARY ...................................................................................... 45
Page 3
Forward
Congratulations on your purchase of a Moog Little Phatty. It was Bob’s dream and it is our pleasure to bring this
performance synth to you. We are very excited for you and expect this product will provide you with a lifetime
of musical enjoyment.
Bob had very high hopes for this, his last design project. His aspiration was for a less expensive Moog synth
that more people could afford to own. If you are reading this manual, we accomplished his goal for at least one
person!
The Moog team is very proud of our effort. We feel we have created a product that not only looks great but
sounds great and is intuitively easy to use. We are hoping you are reading this manual after a week or so of
sleepless but blissful nights of playing the Little Phatty. The LP user interface was designed to have you up and
running in a matter of minutes. The manual will aid you in the discovery of additional functionality beyond the
most important aspect of any synth - simply playing. Hopefully this is the case.
The Little Phatty is built with care and pride by our team in Asheville, N.C. If you have a chance to come to the
beautiful mountains of Western North Carolina, call and come by and see us. We would be happy to take you
on a tour of the factory.
Most importantly, I must recognize the hard working team that created the LP. Of course, it starts with Bob
and his vision for the product. The Engineering team of Cyril Lance, Steve Dunnington, and Mike Peio made it
happen. Kudos go out to Axel Hartmann for his tremendous design and to mechanical engineering genius Klaus
Weber. The software for the LP was developed by the team of Chuck Carlson, Cyril Lance, and Peter Ning.
Thanks to Barry Darnell, one hard working dude, for our board designs. There are a number of people who
provided a timely bit of information along the way: Amos Gaynes, Charles Butler, and Ray Ring.
Thanks to our interns Patrick and Eric for assisting with the assembly of the very rst Little Phattys. If you enjoy
this manual, thank Greg Kist! And then there was a host of artists who participated in the design process: Kevin
Lamb, Steve Donato, Mike Krewitsky, Brian Kehew, Roger O’Donnell, Tom Brislin, Nigel Hopkins, Michael
Vallarella, Keiichi Goto, Tomo Nakamura, Mineto Yamaguchi, Mark Pulver, Steve Molitz, Eric Svalgard, Jordan
Rudess, and Nick Montoya. The internal Moog Marketing team: Jared White, Linda Pritchard, Siobhan Robinson
all contributed their part to the success of this project. And nally, nobody takes more pride in what they do
than the production folks at Moog Music led by Lee Gentry, Operations Manager.
Let us hear from you, as we hope you enjoy it as much as we have enjoyed bringing it to you!
Mike Adams
Moog Music
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LP User’s Manual - The Basics
How to Use this Manual
The Setup and Connections section below explains how to unpack, setup and connect the Little Phatty, and
provides a quick start to get you up and running with your new synthesizer.
The Components section offers detailed explanations of the components that create and modify sound.
First time users should check out the tutorial in Appendix A, where you will nd an explanation of sound
and subtractive synthesis.
For those interested MIDI interface specics, see the section titled “How the Little Phatty handles MIDI”, as
well as the MIDI Interface Specication, Appendix B.
Throughout the manual you will see icons that point out additional information:
This icon indicates an important note concerning the operation of the Little Phatty.
This icon indicates a useful performance or programming tip.
This icon indicates technical information for the advanced user or the technically curious.
Setup and Connections
In a perfect world, everyone would read the User’s Manual from cover to cover before connecting and playing their new instrument. For those of you who don’t live in a perfect world and can’t wait to play your new
synthesizer (completely understandable!), the following should get you set up and running quickly.
Note: We encourage you to read the entire manual at some point to learn more about the
instrument and gain a better understanding of what you can do with the Little Phatty.
Check the contents in the shipping carton
The Little Phatty is shipped with the following items:
1. The Little Phatty Synthesizer
2. Power cord
3. Users Manual
4. Warranty registration card
5. A CD-ROM featuring highlights from the Bob Moog Memorial Celebration service
6. A special Bob Moog Tribute poster
What you will need
In addition to the Little Phatty and provided accessories, you will need:
1. A stand or table sufcient to support the Little Phatty
2. A 1�4” instrument cable and amplier, or a pair of headphones
3. A properly wired AC outlet.
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LP User’s Manual - The Basics
LP User’s Manual - The Basics
Set up
Before you remove the Little Phatty from the carton, make sure you have an adequate place to set it up. You
will need a sturdy keyboard stand or table that will support a 22 lb. analog synthesizer and will not topple
if you play hard. Use caution when lifting the Little Phatty out of the carton, and be sure to save the carton
and all packing material in case you need to ship the Little Phatty for any reason.
Connect to Power
Connect the Little Phatty’s power receptacle (on the side panel) to a wall outlet using the supplied AC power
cord. The Little Phatty’s universal power supply will operate with a power source from 90 to 250 Volts AC, 50/
60Hz.
Power up
Turn the power on. You will see the LCD screen light up and display the message:
Little Phatty
Version 1.0
After a few seconds the start-up screen disappears and the current preset will appear in the display. The
PRESET button will be illuminated in blue, the name of the current preset location and preset name will be
displayed on the top line of the LCD screen, and the message ‘PRESET ACTIVE’ will be displayed on the lower
line of the LCD screen.
Connect to Amplier
Set the Little Phatty’s Volume control to minimum before connecting to an amplier or headphones. Adjust the
amplier level for a comfortable listening level, and then slowly bring up the Little Phatty’s volume. Make sure the
Output ON/OFF switch is illuminated purple – this means the output is turned on.
Start Playing!
Use the VALUE dial to scroll through the presets. All preset locations (00 – 99) are loaded with sounds from
the factory. There are a total of 100 locations in memory for presets – all are user programmable. Note that
once a preset is called up, you can tweak the parameters to your liking using the front panel controls. Any
changes made to the current preset will cause the PRESET button to change its illumination from blue to purple,
and the lower line of the LCD screen will change to ‘PANEL ACTIVE’. If you make changes to a preset and want
to return to the original sound, press PRESET. You can toggle between the stored preset and the current edited
preset by pressing the PRESET button until you change presets. If you wish to save your changes – refer to the
section on Storing Presets on page 23. Any changes made to a preset will be lost if they are not saved once you
change to a new preset.
To learn more about the Little Phatty, keep reading…
Warranty registration
Moog’s on-line warranty registration system is the best way to activate your warranty. Access the Moog
website at www.moogmusic.com and click on the “Product Register” tab. If you complete all the requested
information, Moog will send you a complimentary gift.
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LP User’s Manual - The Basics
Overview and Features
The Little Phatty (LP for short) is a monophonic analog synthesizer that is a descendant of the classic Minimoog
Model D. The LP features 2 ultra-stable oscillators, a genuine Moog 24dB/octave low pass lter, two 4-stage
analog envelope generators and a exible modulation matrix. The LP’s front panel has four variable-function
edit controls for real time adjustment of the Modulation, Oscillator, Filter and Envelope Generator parameters,
plus dedicated controls for Fine Tuning, Octave Switching, Glide, and Volume. The User Interface section has the
controls for Preset selection and management, adjustment of global parameters, and System Exclusive MIDI
function and utilities. The LP features 100 factory preset sounds, which can be modied or replaced by your
own sounds.
Here’s a brief description of the front panel components.
Front Panel:
1. The LCD display and User Interface - provides controls to access presets and other software functions.
The Fine Tune control is located here, along with switches for Glide On/Off and Octave transpose.
2. The Modulation section - features a programmable modulation matrix. The Modulation section has
controls to select the modulation Source (LFO Triangle, LFO Square, LFO Sawtooth, LFO Ramp,
Filter EG or Oscillator 2) the LFO Rate, the modulation Destination (Pitch, Filter, Waveform or
Oscillator 2) and the modulation Amount parameters. The output of the Modulation section is routed
through the Modulation Wheel; when the Mod Wheel is all the way forward the Mod Source passes to
the Mod Destination at the level set by the Mod Amount.
3. The Oscillators section - features two analog oscillators, each with individual Octave, Level and Wave form controls. Additional controls are provided for tuning the second oscillator relative to the rst,
setting the Glide Rate, and engaging Oscillator Sync. The oscillator outputs are summed together along
with the External Audio Input and routed to the Filter section.
4. The Filter section - features the classic Moog 24 db/octave ‘ladder lter’, and includes controls for adjus
ing Cutoff Frequency, Resonance, Keyboard Amount, Envelope Amount, and Overload. The output of
the Filter is routed to the output Voltage Controlled Amplier (VCA), which is controlled by the Volume
Envelope Generator.
5. The Envelope Generator (EG) section - contains two ADSR-style envelopes, one for the Filter and one
for the Volume. The EG section includes controls for adjusting the Attack, Decay, Sustain and Release
parameters of each envelope.
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LP User’s Manual - The Basics
LP User’s Manual - The Basics
Front Panel (con’t):
6. The Output section - includes controls for adjusting the Master Volume, a switch to toggle the output
on and off, and a headphone jack. The Master Volume is used for setting the levels of both the output
and the headphones. The Output On/Off switch affects the Audio Output, but not the headphones.
Side Panel:
The side panel provides connections for Power, MIDI, Control Voltage Input and Audio I/O:
1. Power Socket and Switch – provides power to the LP. Power is ON when the switch is in the up
position.
2. Audio jacks – provides monophonic audio input and audio output connections. The Audio Input jack
allows external signals to be processed by the Little Phatty.
3. Control Voltage jacks – provides control voltage/Expression Pedal inputs for Pitch, Filter, and Volum
parameters, and a keyboard gate input to trigger the envelope generators with a footswitch or gate
signal. These inputs allow the LP to be controlled from expression pedals, or CV devices like the
Moogerfooger® CP-251 Control Processor.
4. MIDI – provides MIDI In and Out connections to other MIDI devices.
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LP User’s Manual - The Basics
Signal Flow
To understand the operation of the Little Phatty, take a look at the diagram below. The diagram shows the
ow of the audio, control voltage and modulation signals in the Little Phatty. Heavy lines are used to indicate
audio signals, which ow from left to right. Lighter lines indicate the control voltages (CV’s), which ow from
the top and bottom. Dotted lines indicate programmable modulation routings.
Referring to the above diagram, the LP’s source signals are created by two voltage-controlled oscillators
and are mixed together with the external audio input signal. This combined audio signal is passed to the lowpass lter, where the tone is sculpted according to the settings of the lter parameters and the Filter ADSR
envelope. The signal then passes to the amplier stage, where the Volume ADSR envelope shapes it. Finally,
the signal is routed to the output section, where the nal level is set by the Master Volume control.
The keyboard is the main control source of the Little Phatty. Each time a key is pressed, the keyboard
produces Pitch CV and Gate signals. The Pitch signal is used to specify the pitch of the oscillators, and is
also applied to the Filter to control the lter cutoff. The Gate signal is used to simultaneously trigger the
Filter and Volume Envelope Generators. The LP can also be controlled through a MIDI connection (not
shown), or through the CV and Gate trigger connections. The resulting sound depends on the various
parameter settings of the oscillators, lter, envelope generators and modulation matrix, plus any additional
CV connections.
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LP User’s Manual - The Basics
Basic Operation
The LP has two operating modes: Master and Preset.
• Master mode allows you to access and change global parameters and other utility options. A complete
list of the Master mode functions and parameters is shown on page 25.
• Preset mode allows you to access the presets and manipulate the sound from the front panel
controls. The Preset mode is the main operating mode for editing and playing the LP. Information
on Preset mode is found on page 23.
When the LP is powered on, it starts up in Preset mode.
In this mode, you select presets using the VALUE encoder.
Press the VALUE encoder to increment by single presets,
or rotate the encoder to step through the presets in either
direction. Pressing the encoder while rotating it increments
the presets by +10 or -10 presets. In Preset mode, you’ll
see the current preset displayed on the top line of the LCD
display, and a ‘Preset Active’ message on the bottom line. The
PRESET button is illuminated in blue. When you edit a preset,
the bottom line of the display changes to ‘Panel Active’ and
the PRESET button changes from blue to purple, indicating
that you are editing the preset sound. By pressing the PRESET
button you can toggle between the preset (stored) and edited
(panel) sounds. Note that once you change preset numbers,
any changes to the previous preset will be lost unless the
changes are saved.
Editing a preset is simple. There are four analog editing controls on the front panel,
one for each of the four sound shaping sections (Modulation, Oscillators, Filter, and
Envelope Generators). Each control is surrounded by a ring of 15 LEDs that indicate
approximately the stored or edited value of the current parameter. The parameters
for each section are chosen by pushing the switch for the desired parameter in that
section. That switch then becomes illuminated in blue. Only one parameter can be
activated at a time for editing in each section.
Some parameters offer multiple selections (such as the Modulation SOURCE switch,
shown at right). Pressing that switch advances through the six possible Modulation
sources. For the On/Off type switches like GLIDE ON/OFF (above), 1-2 SYNC or
OUTPUT ON/OFF, the switch is illuminated purple when the parameter is turned
on, and goes out when the parameter is turned off.
TECH NOTE: The LP’s editing controls are actually analog potentiometers. When a parameter
is selected, the analog control signal is switched to control that parameter directly. This is
called RAC™ (Real Analog Control). Of course the Little Phatty is an analog synth, but the
addition of RAC gives the LP a responsiveness that can only be achieved with analog control.
RAC provides direct access to the analog control signal path; straight to the synthesizer
circuits they control, while still allowing the parameter to be saved in a preset.
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LP User’s Manual - The Components
The Components
Now let’s take a look at the individual module components that make up the Little Phatty Synthesizer, starting with the Oscillator section and moving right across the front panel, explaining the features and functions
of the Filter, Envelope Generator and Output sections. Then we’ll cover the Modulation section, the Keyboard and Left-Hand controls, the Input/Output Side Panel, and the User Interface section.
A. The Oscillator Section
The Oscillators are the main sound source of the Little Phatty. The oscillators in the LP are analog Voltage
Controlled Oscillators (VCOs) that feature a temperature regulation circuit that provides them with excellent tuning stability. The LP’s VCOs can produce a total musical range of 9 octaves!
Oscillator One serves as a master oscillator to which
Oscillator 2 is tuned. The timbres of the oscillators
are adjusted by their variable waveform (Wave)
controls. There is also a switch for syncing Oscillator
2 to Oscillator 1, and a control for adjusting the glide
rate which is explained below.
The frequencies of the oscillators are controlled by a
number of sources. The main source is the keyboard.
The keyboard creates a voltage that allows the
oscillators to be played in an equal tempered scale.
The glide circuit can be switched in between the
Keyboard CV and the oscillators to slow the changes
between notes (portamento). The Keyboard CV is
mixed with the Octave switch CV, the Frequency
control (Oscillator 2), the Pitch Bend Wheel, the
Pitch CV In (on the side panel), the ne tune control,
and the output of the Mod Matrix when the “Pitch”
destination is selected.
Oscillator Section Controls:
Octave:
Each Oscillator has a switch labeled OCTAVE that selects the relative frequency range. To select the octave,
simply press the switch. Each press of the switch advances the setting, as indicated by the corresponding
LED. When the topmost octave is reached, the next button press cycles back to the lowest octave. The
panel markings 16’, 8’, 4’ and 2’ are octave standards based on organ stops. On the 16’ setting the highest A
on the keyboard is A440.
Oscillator Level:
Each oscillator has a switch labeled OSC LEVEL that allows the analog edit control to adjust the oscillator
level. This allows you to control the relative strength of each oscillator in the mixer.
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LP User’s Manual - The Components
LP User’s Manual - The Components
Waveform:
Each oscillator has a switch labeled WAVE that allows the analog edit control to modify the waveform.
The waveform is continuously variable from triangle, to sawtooth, to square, to rectangular. The waveform
is morphed gradually from one to another as the value control is rotated. The legend around the analog edit
control for the oscillator section indicates the knob positions to obtain the triangle, sawtooth, square and
skinniest pulse waveforms. Because the waveform is voltage controlled, this parameter can be modulated.
This allows the generation of some very interesting timbral changes.
By limiting the modulation between the square and thin rectangle
(pulse) waves, you can get pulse width modulation, a classic analog
synthesizer sound. Although the waveforms can be set from the
front panel individually for each oscillator, modulation is applied to
both waveform controls simultaneously. When using modulation, it is
possible to make the width of the rectangular wave so skinny that it
becomes silent.
Frequency:
Oscillator 2 has a switch labeled OSC 2 FREQ that allows the analog edit control to adjust the frequency
of Oscillator 2 relative to Oscillator 1. The pitch of Oscillator 2 can be adjusted up or down 7 semitones
(+/- a fth). By changing the pitch of Oscillator 2, more than one frequency can be played when a key is
pressed, creating intervals for large adjustments, or to get a chorus sound when the oscillators are just
slightly out of tune. Note that Oscillator 1 does not have a frequency control because it is designed to serve
as a reference oscillator.
Sync:
In the center of the oscillator panel is a switch labeled 1–2 SYNC. This is an ON/OFF type switch that
has no interaction with the analog edit control. Sync is ON when the 1-2 SYNC switch is lit. With sync on,
Oscillator 2 is synchronized (synced) to Oscillator 1, forcing Oscillator 2 to restart its waveform from the
beginning each time Oscillator 1 starts a new waveform cycle. The
effect is noticeable if the synced Oscillator is a higher frequency than
the Reset Oscillator. The main frequency heard is that of the reset oscillator. As the frequency of the synced oscillator is swept, it reinforces
the harmonics of the reset oscillator. Use the Oscillator 2 Frequency
control to hear this effect. Depending on how applied, the effect can
be aggressive or warm and vocal.
Glide Rate:
In the center of the oscillator panel is a switch labeled GLIDE RATE. When this is selected, the analog edit
control is used to set the glide rate (portamento) between notes. A Glide switch on the User Interface
panel (on the far left) turns the Glide effect on or off. Glide is the time it takes to go from one note to the
next. The glide rate can vary from virtually instantaneous to a very slow glide (about 5 seconds to go from
the lowest C to the highest C on the keyboard).
Additional CV control:
The PITCH jack on the side-panel is a CV input for external control of the oscillator pitch. This input controls the frequencies of both oscillators. A 1-volt change of this voltage will change the pitch by NOMINALLY one octave. The jack accepts -5 to +5 volts, or an expression pedal like the EP-1.
PERFORMANCE TIP: A steady control voltage applied to the PITCH jack will offset the base
pitch of both oscillators. You can use this feature to transpose the keyboard to any desired
interval applying the appropriate steady-state CV. See Appendix E for more information on
how to congure this.
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LP User’s Manual - The Components
B – The Filter Section
Filters are used for adjusting the timbre of an audio signal. Filters modify sound by attenuating some frequencies while allowing others to pass through unaffected. An important term to understand regarding lters is
“Cutoff Frequency”. This is a frequency at which frequencies begin to be rejected. The LP features a lowpass
lter, which behaves as its name indicates: it allows low frequencies to pass and rejects high frequencies.
Another important aspect of lters is the cutoff slope. The cutoff slope
denes how well the lter rejects signals above the cutoff frequency.
The cutoff slope is measured in decibels per octave (dB/octave), and is
specied as a multiple of six. A 6dB/octave slope (the simplest possible lter design) exhibits a gentle roll-off with a minimum rejection
of frequencies above the cutoff. By comparison, a 12dB/octave slope is
twice as steep, and rejects frequencies above the cutoff twice as fast.
An 18dB/octave slope is steeper still, with a corresponding frequency
rejection. Finally, a 24 dB/octave slope provides the steepest rejection of
frequencies above the cutoff point. The classic Moog lter is a 24dB/
octave lowpass lter.
The Moog lter also features a parameter called Resonance. This
parameter adds a resonant peak at the cutoff frequency. When the
resonant peak passes through the overtones of the sound being ltered, those overtones are reinforced.
This gives the lter a character that can sound vocal, buzzy or zappy,
depending on how it’s used. When the resonance is turned up past
about 3 o’clock on the analog edit dial, the lter begins to self-oscillate
at the cutoff frequency, producing a sine wave tone.
Other lter section controls include Keyboard Amount (KB AMOUNT),
Envelope Generator Amount (EGR AMT) and OVERLOAD.
The KB AMOUNT parameter allows you to set the degree to which the lter cutoff frequency tracks the
note that is played. For example, when the KB AMOUNT is set to it’s highest level (100%), the lter cutoff will rise by an octave each time you play an octave higher on the keyboard. This setting allows you to
maintain a consistent lter tone regardless of whether you play low or high on the keyboard. When the KB
AMOUNT is set to zero, the lter cutoff remains at the value determined by the analog edit control, regardless of where you play on the keyboard. This can make the sound less bright as you play higher up on the
keyboard. The KB AMOUNT parameter includes the keyboard GLIDE control signal, which allows the lter
cutoff to follow the glide of the notes being played (when GLIDE is switched ON). Using the KB AMOUNT
control, you can adjust the amount of Glide that will affect the lter cutoff.
The EGR AMNT parameter allows you to set the degree to which the Filter EG affects the lter cutoff
frequency. The EGR AMNT parameter is bi-polar, meaning the Filter EG can affect the lter cutoff either in
a positive or negative way. A positive amount will cause the Filter EG to raise the cutoff frequency, while a
negative amount will cause the Filter EG to lower the cutoff.
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LP User’s Manual - The Components
LP User’s Manual - The Components
Finally, the OVERLOAD parameter allows you to set the amount of signal clipping from none to soft to
hard clipping as the amount is increased. The results you get with OVERLOAD will depend on the settings of the oscillator waves and levels, and the lter cutoff and the lter resonance settings in addition to
Overload amount. Overload is not the same distortion you’d get from a fuzz box. It can an be quite subtly
applied to add just a touch of ‘bite’, or aggressively applied to add a jaggy edginess to the sound.
Filter Section controls:
Cutoff:
When the CUTOFF switch is selected, the analog edit control is used to adjust the lter cutoff frequency.
The cutoff frequency is adjustable from about 20 Hz to 16 Khz. As the edit control is rotated clockwise, the
cutoff frequency is increased, allowing more of the signal harmonics to pass through the lter.
Resonance:
When the RESONANCE switch is selected, the analog edit control is used to adjust the lter resonance.
Resonance causes feedback in the lter circuit, adding harmonic emphasis at the cutoff frequency. When the
Resonance control is all the way down, the lowpass lter acts basically as a tone control, rolling off the high
end of the signal as the Cutoff control is turned down. As Resonance is increased, the lter begins to form a
peak at the cutoff frequency. This emphasizes harmonics near the cutoff frequency, and can result in a ‘wahwah’ effect when resonance is set fairly high and the lter cutoff is varied. As the resonance is turned up the
peak increases in strength until it begins to self-oscillate – creating a sine wave with the same frequency as
the cutoff frequency.
Keyboard Control Amount (KB AMOUNT):
When the KB AMOUNT switch is selected, the analog edit control is used to adjust the amount of postglide keyboard voltage that is routed to the lter cutoff frequency. When the edit control is rotated fully
clockwise, the lter cutoff follows the key played on the keyboard. A higher key will cause a higher cutoff
frequency. This allows a sound to retain its brightness as it is played higher on the keyboard.
Envelope Generator Amount (EG AMOUNT):
When the EG AMOUNT switch is selected, the analog edit control adjusts the amount of the Filter Envelope Generator output that affects the lter cutoff. The EG Amount is bi-polar, as indicated on the panel so
the amount is 0 when the edit control dial is at the 12 o’clock position. Rotating the control CW from that
point adds a positive EG amount to the lter cutoff, while rotating the control CCW from that point adds a
negative amount to the lter cutoff.
Overload:
When the OVERLOAD switch is selected, the analog edit control adjusts the amount of pre-lter and postlter clipping. Overload can be used to warm up sounds and give them a distinctive tonal edge. Advancing
the edit control increases the amount of clipping from the subtle warmth of soft clipping to the ‘growl’ provided by the beginnings of hard clipping. When set to 100%, Overload adds a volume boost of about +6dB.
Additional CV control:
The FILTER jack on the side-panel is a CV input for external control of the lter cutoff parameter. The jack
accepts -5 to +5 volts, or an expression pedal like the EP-1. A voltage applied to this jack is added to the
setting of the lter cutoff control. A one-volt change in the control voltage will change the cutoff frequency
of the lter by about one octave.
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TECH NOTES:
1. The LP’s Overload circuit uses asymmetrical clipping, which clips each side of the waveform
differently. Asymmetrical clipping circuits tend to produce tones with unique richness and character.
2. The Overload circuit has no effect on the sound when the analog edit control is set fully counterclockwise. Advancing the control gradually introduces the effect, starting with a gentle overdrive-like
quality that becomes increasingly aggressive and edgy as the control reaches 100%. Because the
Overload uses clipping, some sounds, such as a squarewave with the lter cutoff all the way up,
aren’t affected much by increasing the Overload amount. Try sounds tuned to intervals other than a
unison, and a slightly resonant lter setting to really hear the effect.
3. The name “Overload” came from the Overload indicator on the Minimoog, where if the output
was patched back into the audio input the Overload indicator would go on. Mixing the Audio in
would provide a “fatter” sound by increasing the level of signal coming out of the mixer and going
into the lter.
C – The Envelope Generators Section
Musical sounds have a start, middle and an end. For example, a plucked string sound starts with an initial
burst of energy and then slowly fades out until it is silent. In synthesis terms, this progression is called an
envelope – a shape that denes the changes that occur in a sound over time. An envelope can dene any
aspect of change in a sound – volume, timbre, or pitch. The circuits that create envelope control signals in
synthesizers are called Envelope Generators (EGs).
The Little Phatty has two identical EG circuits. When triggered, these circuits produce time-varying control voltages
having a start, middle and an end. The parameters that
specify this progression are the Attack, Decay, Sustain and
Release controls, sometimes abbreviated as ADSR.
Attack determines the character of the onset of the sound.
The Attack control adjusts the time it takes when a key is
pressed for the envelope to go from 0 to full value (the
fade-in time). The Decay control adjusts the second stage
in the evolution of a sound before it sustains or dies out.
Decay is the time that it takes for the signal to drop from
the full level to the level set by the Sustain control. The
envelope will stay at the sustain level as long as a key is held
down. When the key is released, the Release control determines how long it takes for the sound to fade out.
The Little Phatty has one EG dedicated to the lter (to control
the cutoff frequency), and one EG dedicated to the amplier
(to control the volume). The Filter EG can also be used as a
modulation source through the Modulation Matrix.
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LP User’s Manual - The Components
Envelope Generator Section Controls:
Attack:
When the ATTACK switch is selected, the analog edit control is used to adjust the Attack time of the corresponding envelope from 1 msec to 10 seconds.
Decay:
When the DECAY switch is selected, the analog edit control is used to adjust the Decay time of the cor-
responding envelope from 1 msec to 10 seconds.
Sustain:
When the SUSTAIN switch is selected, the analog edit control is used to set the Sustain level of the corre-
sponding envelope.
Release:
When the RELEASE switch is selected, the analog edit control is used to adjust the Release time (the time
for the envelope to return to zero) from 1 msec to 10 seconds.
Additional Control:
The KB GATE jack on the side panel is a trigger input that accepts a footswitch (momentary, normally
closed like the Moog FS-1) or a gate signal. Pressing the footswitch or applying a gate signal (+5V) causes
both envelopes (Volume and Filter) to trigger.
PERFORMANCE TIP: Plugging a FS-1 footswitch into the KB GATE jack allows you to trigger
or sustain a note using your foot without playing the keyboard – useful if you want to free-up
both hands to modify two panel functions at once.
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