The Gristleizer Eurorack Module

The Gristleizer is a legendary VCA/VCF effect used extensively by industrial music pioneers Throbbing Gristle. Developed by a 15 year-old Roy Gwinn and published in a DIY electronics magazine in 1975, the original design found its way to Throbbing Gristle, who brought the Bias trimpot to the front panel and dubbed it The Gristleizer.

Decades later, Endangered Audio Research released the first production Gristleizer tabletops, which faithfully recreated the circuit while solving many of the problems inherent in the original design.

Now, after 8 years of continuous refinement, including a major overhaul of the filter circuit, expanded controls, and more CV options, Endangered Audio Research presents the Eurorack version of The Gristleizer.



Bias - in VCA mode, the amount of distortion and shape of the modulation; in VCF mode, the filter's center frequency
Gain - the amount of signal drive in the first gain stage
Filter Mix - the amount of dry signal added to the filtered signal in VCF mode - also acts as a presence control in VCA mode
Freq - the frequency of the LFO
Depth - the intensity of the modulation
Level - the output level of the module


VCA/VCF - selects between VCA and VCF modes
In/Out - true bypass


In - signal to be Gristleized
Out - Gristleized signal (when not bypassed)

>> Control Voltage Inputs

Bias - External control of the Bias voltage. Can be modulated by any signal of sufficient strength. This is a switching jack - when patched, it disconnects the BIAS knob on the front panel.
Bias Mix - Same as the Bias In, but does not disconnect the front panel Bias control. Instead, the external input is mixed with and offset by the Bias knob.
Freq - External control of the LFO frequency. This is a switching jack - when patched, it disconnects the FREQ knob on the front panel.
Freq Mix - Same as the FREQ IN, but does not disconnect the front panel FREQ control. Instead, the external input is mixed with and scaled by the FREQ knob.
Mod - This switching jack is normalled to the Triangle LFO, meaning you do not need to patch the module for it to function. Inserting a patch cable will break this connection and allow you to modulate The Gristleizer with any modulation source, including LFOs, envelopes, sequencers, sample & hold, and audio.

>> Control Voltage Outputs

Triangle - Triangle LFO
Saw - Saw LFO
Square - Square LFO - not a true square wave, but optimized with sloping rising and falling edges to prevent the clicking that plagues the original design.