Random Source Generator (RSG)

The Random Source Generator is a fully analog voltage-generation and processing module built around three core subsystems: a high-entropy noise source, dual random voltage processors, and a precision Sample & Hold (S&H) circuit. Together, these blocks form a flexible and musically responsive tool for modulation, generative sequencing, and experimental sound design.

1. Noise Generation

At the heart of the module is a classic Serge analog noise core that produces two independent noise types:

White Noise

A broadband, flat-spectrum noise source suitable for audio textures, modulation jitter, or feeding into the Sample & Hold for traditional stepped-random voltages.

Pink Noise

A spectrally weighted noise output with reduced high-frequency content, ideal for natural-sounding modulation, filter excitation, or more subdued random behavior.

These signals serve both as standalone audio/modulation sources and as internal feed options for generating random voltages.

2. Random Voltage Generation

The classic Serge Random Source circuit provides two distinct flavors of analog randomness:

Random DC Output

A slowly fluctuating random control voltage created by shaping, smoothing, and conditioning noise. This output is suited for:

• evolving modulation

• pitch wandering

• drift and generative sequencing

• parameter offsets with organic motion

• Voltage Range 0-5V

It produces musically steady, stepped or wandering control signals.

Random AC Output

A rapidly varying random voltage emphasizing higher-frequency fluctuations. This signal excels at:

• adding texture or instability to modulation

• audio-rate chaotic modulation

• enriching otherwise static CV patterns

• Voltage Range +/-2.5V

The DC and AC outputs complement one another, offering both slow, organic drift and fast, energetic randomness.

3. Sample & Hold (S&H)

The Sample & Hold section is designed for clean, precise sampling of any input signal—noise, modulation, CV, or even audio.

Buffered Input

The incoming voltage is conditioned through a high-impedance buffer to maintain accuracy, stability, and predictable behavior regardless of source.

Clock & Trigger Operation

The S&H can be activated by:

• External clock or trigger signals

• A dedicated manual pushbutton

Each trigger samples the input voltage and holds it until the next event.

Precision Hold & Output Buffering

A high-quality analog switch and hold capacitor capture the input voltage, while a low-droop output buffer ensures:

• long-term stability

• minimal voltage sag

• reliable behavior even under heavy patching loads

The S&H output provides clean stepped voltages ideal for pitch sequences, modulation patterns, rhythmic randomness, or synchronized CV effects.

Audio-Rate Sampling

When fed audio and clocked at high frequency, the S&H acts as an analog sample-rate reducer. This produces gritty, stepped “bit-crushed” textures and opens up a completely different sonic palette.

Technical Summary

The Random Source Generator offers:

• White & Pink Noise for modulation or audio

• Two independent random voltage outputs (slow DC and fast AC)

• A precision Sample & Hold with both manual and clocked operation

• Low-noise buffering and stable output stages for consistent performance

• Creative behaviors including audio-rate stepping, generative CV patterns, and textured modulation by integrating noise, randomness, and sampling into one module, it becomes a highly adaptable tool for ambient compositions, generative patches, chaotic systems, and experimental sound sculpting.

  
  
  

LGE009 DIY Build documentation:
LGE009 Mouser Cart (does not include some panel / mechanical items) (knobs, stand offs, screws, potentiometer not included on list)
LGE009 Main PCB Bill of Materials
LGE009 Main PCB Schematic
LGE009 Main PCB Designators
LGE009C I/O PCB Bill of Materials
LGE009C I/O PCB Schematic (wiring diagram)
LGE009C I/O PCB Designators
Mechanical Parts BOM generally required for building Low-Gain Electronics Modules

** 4U Modular is a term used for the format most commonly known as “Serge Format” or “Loudest Warning Format”. Out of respect for the ever growing format, 4U Modular is the easiest way to refer to it. More Specifically it refers to the panel height and mounting hole style. 4U Modular will patch up just fine with other 4U "Serge" formats such as "Random Source", but it will not mount in RS boats or Buchla Boats (or power off Buchla power for that matter). An info page about this will be added to the website soon to make this a lot more easy to understand.

Details:

• PCB Size: 6” x 1”

• Current Draw: TBD