Catalyst Audio - Model 156M CV Processor


The Model 156 Control Voltage Processor was developed as a front end for the dual oscillator of Buchla’s 100 series. The module is composed of two circuits, each can mix, offset, compress and invert signals. Catalyst Audio’s Model 156M transfers the classic Buchla concept to the Eurorack world. Thanks to its overhauled design, the Model 156M is fully compatible with the 1v / octave standard. An exact clone of Buchla’s Control Voltage Processor is available under the name Model 156V.



The CV processors of the Model 156M were primarily designed to alter pitch signals. Each circuit is equipped with two inputs. A potentiometer allows users to crossfade between control voltages coming from both connectors. Another knob can be used to introduce positive or negative offsets, meaning it is usable for transpositions. The third potentiometer compresses pitch CV signals and / or inverts them. Results are emitted via two outputs per CV processor.

All modules of the Catalyst Audio 100 series were A/B tested with an original 100 series system. The analog circuits feature a discrete, transistor based design. Hand-picked components guarantee high performance, durability and excellent sound. Audio and CV levels have been adjusted to be compatible with the Eurorack standard. Op-amps were used for this task. The components can be removed from the signal flow via jumpers.

3U Eurorack module, 14 HP wide, 45 mm in depth
Power consumption: 35 mA at +12 V

0.2 kg
Article Number

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