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Cerulean (Legacy)

Based On
Marshall® Bluesbreaker
Effect Type
Build Difficulty
Project Summary
A classic overdrive effect that was designed to mimic the Marshall Bluesbreaker amplifier from the 1960s, the Bluesbreaker is also the source circuit for a number of high-dollar "boutique" guitar pedals.

Legacy PCB

Designed for the 1590B enclosure with side-mounted jacks, which some builders prefer. Bypass PCB (optional) sold separately.


In stock

Updated Version

The same circuit, but updated for the 125B enclosure format for a more streamlined build. The bypass switch PCB is integrated.


In stock

Project overview

With this project, you can build an original Bluesbreaker or either of the most popular clones, the Analogman King of Tone and the JHS Morning Glory, or your own custom flavor. Like the Stratus (Tube Screamer) project, its feedback clipping section is extremely flexible and allows for any imaginable combination of diodes as well as a switch to go between two configurations. The second switch optionally allows you to include a Bright Cut mod (from the Morning Glory) or a hard-clipping mod (from the King of Tone).

Demo videos

Here’s a demo video from Ryan Wood testing out a Cerulean built to Morning Glory specs: