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Convex Parallel Compressor

Based On
Dinosaural OTC-201
Effect Type
Build Difficulty
Project Summary
An exceptionally rare and unique optical compressor designed by Dan Coggins of Lovetone fame.

Complete Kit

What's included?
PCB, finished enclosure, hardware,
and all electronic components.


In stock

Convex Parallel Compressor printed circuit board

PCB Only

What's included?
Just the PCB. Build instructions and parts list can be viewed or downloaded from this page.


In stock

Project overview

The Convex Parallel Compressor is a clone of the Dinosaural® OTC-201 Opticompressor, an all-original optical compressor designed by Dan Coggins, the chief engineer & circuit designer for Lovetone. It was originally traced by Aion FX in 2019.

The OTC-201 was made in very small numbers between 2013 and 2016 and remain exceedingly rare today. Despite this, they are universally acclaimed by the few who have had a chance to try one, and an OTC-201 can even be found on the pedalboard for Ed O’Brien of Radiohead.

Today, an updated version of the Opticompressor called the Fat General is available from ThorpyFX, also designed in collaboration with Dan Coggins. This version adds a treble control to allow a more jangly tone to be dialed in, but is otherwise basically the same circuit as the original.

The Convex is a direct clone of the original OTC-201, with two modifications. First, the internal Mode switch has been moved to the outside, so the blend/direct modes can be more conveniently switched between. Second, while the original OTC-201 was buffered bypass, the Convex adds an internal slide switch that allows you to select between true bypass or buffered bypass.

Demo Video

Check out RJ Ronquillo’s demo video of the Convex Parallel Compressor.
Watch on YouTube →