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Behringer

Behringer CP3A-O Oscillator Controller - Eurorack Module

★★★★★4.1 (7 reviews)

Faithfully recreated analog oscillator control from the legendary Modular 55 & 35 Series, now in a compact 8HP Eurorack format.

$31.90*
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*Price sourced from Amazon.com. Last updated:Jun 04, 2026.Price and availability are subject to change.

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Overview

The Behringer CP3A-O Oscillator Controller is a purpose-built Eurorack module for anyone serious about recreating the control architecture of the legendary Moog Modular 55 and 35 Series synthesizers. Where most modern Eurorack oscillator modules focus on sound generation, the CP3A-O handles the control layer — managing and routing the CVs that shape how your oscillators respond to the patch. The analog circuitry reproduction means you get the same voltage-handling behavior as the original hardware: the subtle non-linearities, the feel of classic CV interaction, and the hands-on control that made the Modular 55 a studio fixture for decades.

At 8HP, the module is efficient in a rack without being cramped, and the build quality reflects Behringer's investment in their analog Eurorack line. The 6.35mm jack connectivity is a direct nod to the original system's hardware format. Where this module shines is in a deliberate build — someone assembling a Behringer Eurorack system around the Modular 55 & 35 architecture who wants authentic signal path behavior, not a modern approximation. Under session pressure, analog modules like this one reward careful gain staging and thoughtful patching; the CP3A-O is no exception, delivering predictable, musical CV control when integrated properly into an oscillator-focused modular system.

Key Features

Module type: 8HP Eurorack oscillator controller module

Circuitry: Authentic reproduction of the circuitry from the Modular 55 & 35' Series

Product name: Behringer C3PA-O Oscillator Controller Eurorack Module

Item type: Sound modules, suitable for keyboard instruments

Connector type: Features 6.35mm Jack connector type

Skill level: Suitable for beginners

Special feature: Portable and easy to use

Specifications

Module Type
Eurorack Oscillator Controller
Width
8HP
Series
Modular 55 & 35
Connector Type
6.35mm Jack
Brand
Behringer
Model
CP3A-O

Pros & Cons

👍 Pros

  • Authentic circuit reproduction of the Moog Modular 55 & 35 Series oscillator controller brings vintage analog control behavior at a fraction of the cost.
  • Compact 8HP width keeps rack real estate consumption low while delivering dedicated oscillator management functionality.
  • Part of Behringer's broader Eurorack ecosystem, making it straightforward to combine with other CP-series modules for a cohesive classic modular architecture.
  • Analog circuitry means control voltages interact with the warmth and slight non-linearity characteristic of the original hardware.
  • Portable and lightweight, making it practical for modular setups that move between studio and live environments.

👎 Cons

  • Limited publicly available documentation makes it difficult to confirm exact CV input/output ranges without hands-on testing or community resources.
  • The 6.35mm connector format can feel out of place in a fully 3.5mm Eurorack environment and may require adapters.
  • As a controller rather than a sound-generating module, its value is only realized in the context of a more complete oscillator-based patch — it adds nothing to a minimal or digital-focused system.
  • Beginner-marketed positioning may understate the patching knowledge required to use it effectively in a complex signal chain.

Frequently Asked Questions

The CP3A-O is an oscillator controller — it provides control voltage routing and management for oscillators in your modular system, faithfully replicating the control architecture of the original Moog Modular 55 & 35 Series. It lets you shape how CVs interact with your oscillators for classic analog behavior.
The CP3A-O is a standard Eurorack module powered via the Eurorack bus connector. Verify your case's power budget before installation, as analog circuitry can draw more current than digital modules — check the Behringer spec sheet for exact mA requirements on both +12V and -12V rails.
The 6.35mm (quarter-inch) connector on the CP3A-O is a connectivity feature carried over from the original Modular 55 & 35 design. In the original series context, these were used for patching control signals — review the module's patch diagram to understand the signal type at each jack before patching.
8HP is a moderate footprint — it fits comfortably in most 84HP or 104HP cases alongside other utility and oscillator modules. Plan your rack layout so patch cables to and from the CP3A-O don't obstruct adjacent modules.
Behringer lists it as beginner-suitable, but oscillator controller modules are most useful once you understand CV relationships and signal routing basics. New modular users will get more from it after experimenting with a VCO and basic envelope/LFO patching first.

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