Image 1 of 8
Image 2 of 8
Image 3 of 8
Image 4 of 8
Image 5 of 8
Image 6 of 8
Image 7 of 8
Image 8 of 8
AD633 Quadruple Multiplier IC – The Heart of Versatile Modulation
The AD633 is hands down one of my all-time favorite ICs — a powerful, 4-quadrant multiplier that requires almost no external components to function. Perfect for modular synth enthusiasts, this chip shines as both a ring modulator and amplitude modulator, offering incredible flexibility with minimal fuss.
What makes the AD633 truly special is its ability to invert the output signal’s phase whenever the modulator signal goes negative. This unique behavior transforms it into a “thru-zero” (TZ) voltage-controlled amplifier (VCA) or a voltage-controlled bipolar attenuator, opening up a world of creative possibilities. Whether you want subtle modulation or dramatic signal shaping, this chip delivers with character and precision.
Introducing the LGE022 Dual AM/RM – Modular, Expandable, and Ready to Play
Version 1 of the LGE022 PCB was designed as a compact module to sit between your system’s panels, providing a simple 3-jack interface for Ring Mod / TZ / Bipolar VCA functionality. Inspired by Ray Wilson’s ingenious AM mode implementation, the latest revision now includes dedicated AM and RM modes, carefully balanced for equal output levels and DC coupling — perfect for seamless CV integration without pesky coupling capacitors.
A key improvement in the current version is the addition of a bipolar attenuator on the modulation input, giving you precise control over the modulation depth and polarity before it hits the AD633 chip. This enhancement makes it even easier to “modulate the modulator,” providing dynamic and expressive CV control right at your fingertips.
The PCB is thoughtfully designed to snap in half for flexible installation, whether you want a single unit or a dual AM/RM setup. Plus, power supply components are streamlined so you don’t have redundant parts if building the dual version.
Endless Modulation Fun and Learning Opportunities
This board is not just versatile; it’s also an excellent project for beginners. The AD633 IC might be a bit of an investment, but it simplifies your build while delivering outstanding sonic results. Use it standalone, or combine it with other modules to explore advanced modulation techniques with voltage-controlled bipolar attenuation.
For those eager to dive deeper into modular synth circuit design, I highly recommend checking out Ray Wilson’s website and book — invaluable resources for understanding and creating incredible synth modules.
Why settle for one? Every system should have at least one AD633 module — or better yet, a whole bank of eight!
Version 3 DIY Building Information (Added Bi-polar attenuator to modulation input)
LGE022 V3 Main & I/O Board Mouser Cart (Does not include mechanical parts like knobs, pots, board to board headers, screws, etc)
LGE022 V3 Main Board Bill of Materials
LGE022 V3 Main Board Schematic
LGE022 V3 Main Board Designator Layout
LGE022C V3 I/O Board Bill of Materials
LGE022C V3 I/O Board Schematic (Wiring Diagram)
LGE022C V3 I/O Board Designator Layout
Version 2 DIY Build Information: (Unipolar Attenuator for Modulation Input)
LGE022 V2 Main Board Bill of Materials
LGE022 V2 Main Board Schematic
LGE022 V2 Main Board Designator Layout
LGE022C V2 I/O Board Bill of Materials
LGE022C V2 I/O Board Schematic (Wiring Diagram)
LGE022C V2 I/O Board Designator Layout
Version 1 DIY Build Info:
LGE022 V1 Main Board Bill of Materials
LGE022 V1 Main Board Designator Layout
LGE022 V1 Main Board Schematic
LGE022C V1 I/O Board Wiring Schematic
Mechanical Parts BOM generally required for building Low-Gain Electronics Modules
Details:
PCB Size: 6” x 1”
Current Draw: TBD
** 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.