The Buchla Aux OSC Card is an auxiliary oscillator expansion for the Music Easel ecosystem, providing a dedicated modulation oscillator, CV multiplier, switchable control routing, and enhanced modulation capabilities, compatible with all Music Easel and Easel Command units manufactured post-2012.

Expanded Modulation Capabilities

Buchla’s latest iteration of the classic Easel expansion module introduces a newly designed auxiliary oscillator that operates both as a modulation source and as an audio-rate oscillator. This provides users with deeper sonic flexibility, offering complex modulation possibilities or the addition of a secondary audio signal path. The card seamlessly integrates with current Music Easel Modern, Retro, Easel Command, and Anniversary Edition systems, ensuring enhanced control and performance across the entire Buchla lineup.

Enhanced CV Routing and Signal Processing

The new design replaces legacy features with smarter signal routing and more versatile voltage control. The envelope generator (EG) CV inputs, now standard on the 208c's front panel, are replaced with a highly responsive CV multiplier. This multiplier includes a dedicated control knob that adjusts the modulation depth, allowing for precise signal shaping and dynamic voltage scaling directly from the card.

Updated Pulse and Random Sources

With the 208c now including its own Pulser input, the Aux OSC Card introduces a new random pulse generator in its place. This feature injects unpredictability and organic movement into patches, useful for evolving textures, generative sequences, or rhythmic modulation.

Broader Compatibility and Refined Design

The Aux OSC Card is fully compatible with all Music Easels and Easel Commands released since 2012. It has been optimised for modern workflows and redesigned with a more cost-efficient build compared to the previous generation Aux Expander Card, all while maintaining Buchla's hallmark build quality and performance.