Acid Source ADDAC107 - Synthesizer ADDAC System - Free user manual and instructions

Product Type	Eurorack Synthesizer Module
Brand	ADDAC System
Model	Acid Source ADDAC107
Width	9 HP
Depth	4 cm (approx. 1.6 inches)
Power Consumption	80 mA on +12V, 80 mA on -12V
VCO Frequency Range	4 octaves (tunable via Frequency and Fine Tune knobs)
VCO Waveforms	Triangle or Saw (selectable), plus Square wave
Waveform Mix	Balance between Triangle/Saw and Square
Filter Types	Highpass, Bandpass, Lowpass (selectable)
Filter Controls	Cutoff, Resonance, and CV Attenuverter
VCA Envelope	AD (Attack/Decay) with very short attack and controllable decay
Input Gain	Amplifies external input by up to 2x, allowing saturation
CV Inputs	Frequency CV (with attenuator), Cutoff CV (with attenuverter), Decay CV (with attenuator)
CV Output	Normalled to Frequency and Cutoff inputs; also sends envelope signal
Accent Input	Adds to the input signal for varied amplitude
Audio Output	1/8" mono jack
DIY Kit Available	Yes, full DIY version
Year Introduced	2023
Country of Design	Portugal

Frequently Asked Questions - Acid Source ADDAC107 ADDAC System

How does the Input Gain knob affect the VCA envelope?

The Input Gain amplifies the incoming trigger/gate/CV by up to 2x. This increases the maximum voltage of the AD envelope, which in turn opens the VCA more. Above +5V, the VCA begins to amplify and saturate, adding harmonics to the sound.

Can I use the CV Output to control other modules?

Yes, the CV Output sends the envelope signal from the VCA decay. It is also normalled (internally patched) to the Frequency and Cutoff CV inputs, creating self-patching possibilities without external cables.

What are the filter types available?

A 3-position switch selects between Highpass (HP), Bandpass (BP), and Lowpass (LP). The filter also has Cutoff and Resonance controls with an Attenuverter for the Cutoff CV input.

Does the VCO track 1V/octave?

The manual states the VCO is tunable over 4 octaves and has a dedicated Frequency CV input with an attenuator. While not explicitly stated as 1V/octave, it is standard for Eurorack and should track reasonably.

What is the purpose of the Accent input?

The Accent input adds to the input signal (trigger/gate/CV) to create a different amplitude output. It can be used to emphasize certain notes or beats.

How do I achieve distortion or saturation?

By turning up the Input Gain knob, you can amplify the envelope voltage above +5V. This causes the VCA to saturate, adding harmonics. Combining this with high resonance or filter self-oscillation creates even more complex timbres.

What power does the module require?

It requires 80mA on the +12V rail and 80mA on the -12V rail. Standard Eurorack power connection.

Is the module available as a DIY kit?

Yes, the ADDAC107 Acid Source is also available as a full DIY kit, allowing users to solder their own components.

What is the physical size of the module?

It is 9 HP wide and 4 cm deep (approximately 1.6 inches).

Can I use external envelopes with the VCA?

Yes, the Input jack accepts triggers, gates, or CV. The Input Gain amplifies the signal before the internal AD envelope. You can bypass the internal envelope by using an external VCA.

USER MANUAL Acid Source ADDAC107 ADDAC System

graph TD
    A["ACID SOURCE ADDAC107"] --> B["FREQUENCY"]
    B --> C["FINE TUNE"]
    C --> D["TRI"]
    D --> E["SAW"]
    E --> F["CUTOFF"]
    F --> G["NUL SQUARE"]
    G --> H["MIX"]
    H --> I["RESO"]
    I --> J["HP"]
    I --> K["BP"]
    I --> L["LP"]
    L --> M["INPUT GAIN"]
    M --> N["VCA DECAY"]
    N --> O["FREQ. CV"]
    N --> P["CUTOFF CV"]
    N --> Q["DECAY CV"]
    O --> R["FREQ. CV"]
    P --> S["CUTOFF CV"]
    Q --> T["DECAY CV"]
    U["2023 ADDAC SYSTEM"] --> V["INPUT"]
    U --> W["ACCENT"]
    U --> X["CV OUTPUT"]
    U --> Y["OUTPUT"]

ADDAC System

Instruments for Sonic Expression Est.2009

INTRODUCING

ADDAC107

ACID

SOURCE

USER'S GUIDE, REV01

April.2023

ADDAC

System

From Portugal with Love!

DESCRIPTION

We started this module with the idea of developing a complex drum source however, somewhere along the process, we noticed how much better it performed as a synth voice and simply embraced this lucky accident.

It features a VCO with a [FREQUENCY] and [FINE TUNE] knob plus a dedicated CV Input and Attenuator knob — (tunable over 4 octaves).

The VCO waveform output is achieved by selecting either a Triangle or Saw through a switch. the selected waveform can then be mixed/balanced against the square wave. The resulting mix is then sent to the Filter.

The Filter features a [CUTOFF] and [RESO] resonance knob plus a Cutoff CV Input and Attenuverter knob. A 3 position switch is used to select the filter type: Highpass, Bandpass or Lowpass. The resulting output is then sent to the VCA.

The VCA features an Input with [INPUT GAIN] knob which at maximum can amplify the incoming signal by a factor of 2. This is a very important control (more about it in the next page). It accepts any signal Trigger, Gate or CV. Whatever input is plugged in the signal is then fed through an AD with a very short attack and controllable decay through the [VCA DECA9] knob plus the CV Input and Attenuverter knob.

The resulting slewed signal is then used to control the VCA gain. This signal is also sent to the CV OUTPUT as well as the LED monitor. The Accent input adds to the Input signal creating a different amplitude output

The CV OUTPUT is also normalled to the Frequency and Cutoff inputs.

graph TD
    A["ACID SOURCE ADDAC107"] --> B["FREQUENCY"]
    B --> C["FINE TUNE"]
    C --> D["TRI"]
    D --> E["SAW"]
    E --> F["CUTOFF"]
    F --> G["NUL SQUARE"]
    G --> H["TRI/SAW MIX"]
    H --> I["RESO"]
    I --> J["HP"]
    I --> K["BP"]
    I --> L["LP"]
    L --> M["INPUT GAIN"]
    M --> N["VCA DECAY"]
    N --> O["FREQ. CV"]
    N --> P["CUTOFF CV"]
    N --> Q["DECAY CV"]
    O --> R["0 MAX"]
    P --> S["-"]
    Q --> T["+"]
    R --> U["2023 ADDAC SYSTEM"]
    S --> U
    T --> U
    U --> V["INPUT ACCENT CV OUTPUT OUTPUT"]

This module will also be available as a full DIY kit.

Tech Specs:

9HP

4 cm deep

80mA +12V

80mA -12V

INPUT GAIN

The [INPUT GAIN] knob,

Usually Attack/Decay envelopes have a maximum voltage of +5v, no matter if the input gate is +5v or above the AD will clip at +5v. In this case we did not use this clipping method and instead allow the incoming voltage to determine the maximum AD voltage, meaning that if a +5v gate is present then the AD maximum voltage will be +5v but if a gate of +10v is sent then the AD maximum voltage will be +10v.

This also means that with higher input voltages the decay, although falling at the same speed, will be longer than with lower voltages as it has a longer range to go back to 0v.

As we mentioned before the [INPUT GAIN] knob can amplify the incoming input by a factor of 2, allowing to use a standard +5v gate or envelope and being able to make the resultant AD go up to +10v.

The AD signal is responsible for opening the VCA. Up to +5v the VCA will open to unity gain above this value the VCA will start to amplify and eventually saturate and distort.

This saturation will add harmonics to the signal which will change it's gentle timbrical nature to a more unique and peculiar timbre that will make the module shine in Acid contexts.

Adding high levels of Resonance or even filter self oscillation in combination with high VCA saturation will create even more harmonics that we highly encourage the user to explore.

graph TD
    A["ACID SOURCE ADDAC107"] --> B["FREQUENCY"]
    B --> C["FINE TUNE"]
    C --> D["TRI"]
    D --> E["SAW"]
    E --> F["CUTOFF"]
    F --> G["π/π SQUARE"]
    G --> H["TRI/SAW MIX"]
    H --> I["RESO"]
    I --> J["HP"]
    I --> K["BP"]
    I --> L["LP"]
    L --> M["VCA DECAY"]
    M --> N["INPUT GAIN"]
    N --> O["0 MAX"]
    O --> P["0 MAX FREQ. CV"]
    P --> Q["0 MAX ACCENT"]
    Q --> R["0 MAX CUTOFF CV"]
    R --> S["0 MAX DECAV CV"]
    S --> T["0 MAX INPUT"]
    T --> U["0 MAX ACCENT"]
    U --> V["0 MAX CV OUTPUT"]
    V --> W["0 MAX OUTPUT"]

SIGNAL FLOW DIAGRAM

graph TD
    A["ON/OFF JUMPER"] --> B["FREQUENCY CV IN"]
    B --> C["FREQUENCY INITIAL"]
    B --> D["FREQUENCY FINE TUNE"]
    B --> E["FREQUENCY ATTENUVERTER"]
    C --> F["VCD"]
    D --> F
    E --> F
    F --> G["TRIANGLE OR SAW"]
    G --> H["RECTANGLE / TRI/SAW MIX"]
    H --> I["OUTPUT"]
    I --> J["FILTER"]
    J --> K["VCA"]
    K --> L["CUTOFF INITIAL"]
    K --> M["CUTOFF ATTENUVERTER"]
    K --> N["RESONANCE"]
    K --> O["HP / BP / LP SELECTOR"]
    L --> P["CUTOFF INITIAL"]
    M --> Q["CUTOFF ATTENUVERTER"]
    N --> R["RESONANCE"]
    O --> S["HP / BP / LP SELECTOR"]
    P --> T["INPUT TRIG/BATE/CV IN"]
    Q --> U["INPUT GAIN (MAX - *2)"]
    R --> V["VCA DECAV SLEW"]
    S --> V
    T --> W["LED MONITOR"]
    U --> X["DECAY INITIAL"]
    V --> Y["DECAY ATTENUVERTER"]
    W --> Z["CV OUTPUT"]
    X --> AA["ACCENT"]
    Y --> AA

NORMALLING (SELF-PATCHED)

CONTROLS DESCRIPTION

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