Buchla Aux Card

Expansion card for Buchla Music Easel

With the Buchla Music Easel Aux Card, modulation can be achieved directly through what was previously only available indirectly or through major modifications on/to the Program Card. It also features a digital oscillator/LFO, which can act as a reference oscillator for tuning if needed, and filterable noise. A “Pulse In” input simplifies synchronization to other equipment.

Three CV inputs including attenuators allow for CV control of the “Attack”, “Decay” and “Sustain” parameters of the Music Easel envelope.

Via switches on the Aux Card, the “To Card” input in the inverter section of the Music Easel can control the timbre mix of the Complex Oscillator, select the waveforms of the Complex Oscillator or switch the range mode of the Modulation Oscillator between audio and LFO.

Two additional switches on the Aux Card allow you to use the “To Card” input in the envelope detector section of the Music Easel to switch through the waveforms or modulation types of the modulation oscillator, to select Gate 2 Source, or to change the modes of the lowpass gates.

An internal digital oscillator/LFO can be controlled either by CV, internal bus, Music Easel sequencer or the Pressure CV of the Easel. It offers the CV-controllable waveforms sine and sawtooth as well as a pulse wave with PWM. The audio signal from this oscillator can be mixed with filterable noise. Both the mix and the filter frequency of the noise are CV-controllable.

Regardless of the mix or LFO settings, a blue banana jack always outputs the pure oscillator/LFO signal without noise. At another audio output there is either the Noise/Oscillator Mix or, in LFO mode, only the noise signal, present.

An input titled “Pulse In” can be used via switch to trigger either sequencer, envelope or pulser.

Specifications

Connectors

• Inputs: pulse In, attack cv, sustain cv, decay cv
• Outputs: osc freq, wave, mix, noise filter, osc cv, osc audio
• Weight: 0.4 kg