Welcome to the Revolution

Hi there, welcome to my blog - La Revolution Deux. It's an odd name - but I like it! Here you will find all the info on my various DIY Guitar effects builds, amplifiers and guitars. Everything from a humble Ibanez tubescreamer to the holiest KLON Overdrive.

You may also find a few effects builds that I am looking to move on - usually in exchange for other effects/gear/cash. You can always check my ebay account to see what I've got up for grabs.

Have fun, enjoy the blog - Fred Briggs :-)


Feel free to get in contact with me about anything you see on this blog or with any general questions about guitars, amplifiers and effects, I'll be happy to answer! Just click the button above to email me directly or alternately my email address is fredbriggs2007 [at] googlemail [dot] com

Search This Blog

Monday, 30 January 2012

Catalinbread - Super Charged Overdrive

The Super Charged Overdrive has been part of the Catalinbread range now for a while - as you can see above it's had three style make overs so far (the top image showsthe SCOD's current form.). It's a fairly high gain beast, and utilises those old Logic chips with their internal mosfets for the circuit's gain structure and clipping. Here's the description from the Catalinbread Website:

"SuperCharged OD The audio equivalent of a forced induction high displacement big block make up the heart of the SCOD's "distortion powerplant". It is designed like a tube amp, fine tuned cascaded gain stages cause the distortion, not diodes. We knew we had a winner when it made our 5W 6V6 amp push air like a full stack. This pedal rocks harder than a Heart 8-track in a Hemi Cuda outside of a high school in 1978!

The tone for leads is balanced, focused, and sustains forever. Chords are chunky, tight, and resonant. Turn the GAIN and CONTOUR down for hi-wattage British sounds. Increasing the GAIN brings you into more modern saturation teritories without un-natural compression.Crank the CONTOUR knob and you tighten up the lowend adding resonance of a sealed 4x12.

The SCOD is capable of huge amounts of output and the gain can be down right METAL. Inspite of this the noise level is remarkably low. The distortion is natural without the buzzy "chopping" or "squaring" of your guitar's signal as often associated with high gain and metal pedals. This means you can play chords with your SCOD and not cause bizarre intermodulation.

Don't be surprised to find your daily 30 minute practice session lasting an hour or more with the SCOD. This pedal is truly inspiring."

And here's a demo video of the SCOD in action:

Pretty gainy stuff! Well, it's been a while but the boys over at freestomp have come up with a schematic. Head produced this version from a previous schematic drawn up by MadBean:

The value crossed out are old incorrect values. See the circuit structure - two mosfet boosts sandwiching the logic chip. Inside there are more cascaded mosfet stages mean this thing has 5 cascaded gain stages! No wonder it's go so much gain available!

Inside that 4007 chip it looks a little something like this (Thank's Mictester for pointing this out):

It's a circuit designed by Gez from the late 90's called the "Nut Cruncher".

Here's the freestompboxes.org forum thread for reference: http://freestompboxes.org/viewtopic.php?f=7&t=2945


  1. Is there a PCB layout floating around for this yet?

  2. I'll keep my eyes out, one is in the pipeline...


Comments are welcome on Revolution Deux. However, please do not spam links to unrelated sites - these comments will be removed! Thanks - Briggs.