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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

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Sunday, 22 January 2012

Catalinbread - Formula No 5

I like CAtalinbread pedals, Nick does a really good job designing and building some great sounding boxes. Here's the Catalinbread Formula No 5 - a supposed 5E3 emulator from them. It sounds great and, justifiably, there's been a lot of interest in the pedal. Here's the description from the Catalinbread website:

"The Formula № 5 was inspired by old tweed amps, most notably the 5E3 circuit. The character of the 5E3 is very unique. It has very minimal power filtering, low plate voltages, elemental tone stack, and does next to nothing to control the low end between gain stages, not to mention the under-rated output transformer and speaker. The entire system runs inefficiently resulting in a loose bass, greasy mids, cutting treble, and incredible grit – none of these qualities were ideal or intentional back in the day. In spite of this, over the past five decades the amp inspired some of the coolest, most sought after guitar tones ever recorded."

Here's a demo video of the Catalinbread Formula No 5:

Here's the schematic provided by Coldcraft after a unit was traced over on freestompboxes:

As you can see it's a combination of two cascaded "mu" booster stages with a tone/gain section in the middle - much like the Catalinbread Dirty Little Secret. It sounds great and that mis-biased first booster stage creates some great asymetrical clipping harmonics. I'd build/buy this pedal - it rocks.

Here's a vero layout by Roseblood11:

Here's the freestompboxes.org topic for reference: http://www.freestompboxes.org/viewtopic.php?f=7&t=9373


  1. Hi, This vero layout for the Catalinbread Formula NO 5 by Roseblood11, is my first effect pedal build. The pedal sounds great, but mine has a volume issue. At full volume, it is well below unity with my amp - any ideas on how to fix this?
    Thanks for all these wonderful builds!

  2. You have an error at least somewhere on you layout - check for missed trace cuts and solder bridges. Also recheck all of your off board wiring. You should get way over unity gain with this thing!

  3. Hi Fred
    Any chance you could let us know the voltages you're getting on the FETs? i'm not sure I've got the layout right.

  4. Built this and cannot get any sound out of it. Checked evrywhere for shorst and cannot fing any. Is this layout bunk?

  5. Layout is fine; verified.

  6. Hi, the 47 pF cap (C3 in the schematic, C1 in the vero) is actually supposed to be 470 pF as discussed on freestompboxes.org:


    In the original Fender 5E3 circuit a 500 pF cap (marked as 0.0005 µF) is used. 47 pF will yield a too trebly voicing.

    Cheers, Sebastian


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