ALM Busy Circuits FMco

Compact VCO and FM-synthesized voice with integrated envelope and 4-voice chords

• VCO and voice based on 2-operator FM synthesis, original ALM DSP implementation
• Inspired by Akemie modules but optimized for more intuitive use and a more modern sound
• Manual and CV control of FM Index, Ratio, and classic operator waveforms
• Integrated decay envelope routed to FM depth and output level
• 4-voice chords controllable via CV
• Encoder-based tuning system for precise and immediate pitch adjustment
• Wide stereo output, all in just 8HP

ALM Busy Circuits FMco is a compact VCO and voice based on FM synthesis for your Eurorack system. It features an ALM-original DSP implementation of 2-operator FM synthesis, inspired by Akemie modules but tuned for more intuitive use and a more contemporary sound, offering a wide palette of FM timbres through a simple and essential set of controls.

FM Index, Ratio, and Operator Waveform Control

The FMco offers both manual and voltage-controlled adjustment of FM Index, Ratio, and a selection of classic operator waveforms, allowing you to explore a wide range of FM sounds—from metallic and bell-like timbres to deep bass and cutting leads—all starting from just a few intuitive controls.

A built-in envelope for a complete FM voice

An integrated decay envelope is routed to both the FM depth and the output level, allowing the FMco to function as a complete synthesizer voice when triggered, without the need for additional modules for dynamic sound shaping.

4-voice chords and wide stereo output in just 8HP

The FMco also features CV-controllable 4-voice chords, an encoder-based tuning system for precise and immediate pitch control, and a wide stereo output. The result is a remarkable amount of FM synthesis packed into a compact 8HP form factor, ideal for those seeking tonal depth without sacrificing space in their modular system.

Technical Specifications

• Power Supply: +12V 65mA / -12V 25mA
• Size: 8HP
• Depth: 32mm
• 2-operator FM synthesis, original ALM DSP
• Manual and CV control over FM Index, Ratio, and operator waveforms
• Integrated decay envelope routed to FM depth and output level
• 4-voice chords controllable via CV
• Encoder-based tuning system
• Wide stereo output