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

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Tuesday, 31 January 2012

Fred Briggs - Octave Ringmod Fuzzer (ORF)

Here's the next new project from myself. It's a fun little circuit for you, inspired by Tim Escobedo's Tripple Fuzz. At lower gains it creates a really sweet tone, push it high and it gets truly evil! Stack it into other gain pedals for an absolute fuzz out heaven :-)

Here's the schematic:

The transistors I used where BC557 and BC548, the op amp was a LF351. The optional J201 gain stage adds a lot of character, I prefer this build with it...

Fred Briggs - Bliss; Overdrive/Boost/FX Loop

Here's a new little project for you. I designed it for a friend who wanted something that would give his old pedals a new lease of life, well here it is. You stick your old gain pedal into the loop and whoosh -> extra life. More dynamics, more warmth, it's all there. Here's the schematic:

So you wanna build a Dumble Overdrive Special?

The Dumble Overdrive Special has been one of the "Holy Grail" guitar amps for many years. So what are the chances of you getting your paws on one? It is thought that there may only be around 300 original Dumble amplifers in existance with the asking price now from $20,000 - $50,000! That's probably not an option for most of us, so what can we do for that Dumble tone? Well, we'll make our own won't we :-)

Here's a great clip of an original Dumble Overdrive Special in action:

There are quite a few kits out and about these days, one of the most widely known and reviewed as "the best" is the Ceriatone Overtone Special which can be found here: http://www.ceriatone.com/productSubPages/OTS%20Series/OTSMain.htm

Here's a layout for the Overtone Special 50 (A Dumble Overdrive Special 50W Clone):

The Kits at Ceriatone are fairly well priced. Obviously if you can find your own suitable donor chasis you'll cheapen up the build considerably!

Here's a demo video of the Ceriatone Overtone Special in action:

They do sound pretty sweet, really smooth and break up so nicely with single coil pickups. If I had the cash I think I'd be going for a DIY Dumble build asap!

There are a great set of instruction videos on youtube created by Tony McKenzie which document his building of a Ceriatone Overtone HRM kit, here they are for you:

He's also reviewed the amp too, check out his site here: http://www.tonymckenzie.com/ceriatone_hrm_review.htm

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

Dr Z Amps - Carmen Ghia

Ahhh, the Dr Z Carmen Ghia. It's long been ranked as one of the best sounding boutique amps available. It's an all out take on the classic Marshall 18 Watt, great for any rock tones you need but with a clean headroom that gives the amp some versatility. Here's the description from the Dr Z Website:

"At first glance, the Carmen Ghia looks rather, well, modest. This is why the Ghia leaves so many people floored from the first note. Clean notes come out with a warmth, complexity, and sustain like one has never heard from such a small amp. Every note has a hugeness to it that seems far beyond an 18 watt head. All this comes before the amp really starts to sing. As you turn the Volume clockwise, the fun factor increases. The big clean notes get even BIGGER than they were before. Sustain becomes as smooth and musical as you have ever heard it. Notes seem to sing forever. This is an incredibly fun amp, and you'll have trouble putting your guitar down. The Carmen Ghia interacts with the player because the player can feel the power tube distortion.
This amp has become a favorite in recording studios around the world. It's also a great little amp for small clubs. While many other small amps have trouble cutting through the mix and have a rather flatulent low end, your Dr. Z Carmen Ghia will always cut through the mix tightly and musically."

Here's a demo video of the Carmen Ghia in action:

Here's the schematic file ("The Phoenix Project"):

And here is the verified layout:

 For this build you'll need some transformers right? The 18 Watt (Marshall) style transformers from: http://www.mojotone.com will work perfectly....

 [Here's some guts of a real Dr Z Carmen Ghia]

[Here's a completed build (Dan_Mask's I believe..) build using the above layout]

Saturday, 28 January 2012

Demeter - Compulator

[This post also contains info on the Bajaman Optical Limiter]

The Demeter Compulator has been a popular compressor for a while now. It's got a great level of transparent compression available, is built like and tank and uses decent quality components.

Here's the description from the Demeter website:

"The sound of classic studio optical compression of the 60's and 70's at your feet! The first compressor pedal not to suck the life out of your tone.

Operation is fairly straightforward. There are two inputs on the front side of the unit: a 1/4" input jack on the right and a 1/4" output jack on the left with a battery-ground switch on the input jack.

There are two controls on the unit: compress and volume, plus a foot switch to bypass the effect, and an LED to indicate effect operation. On the side there is a trim pot to set the overall gain of the unit.

Compress affects the amount of gain reduction (compression) of the input signal. Turning this clock wise will give you up to 30dB of gain reduction (depending on input gain). Please note that the Compulators max gain is 26dB (see Trim Pot) so in some circumstances if your instrument is very hot you could achieve less than unity gain if you turn up the compress knob too much.

Volume increases and decreases the output volume of the Compulator. Use this for level matching between the effected and unaffected signal.

Trim pot sets the gain of the compressor's pre-amplifier. If distortion occurs turn this down until the signal is clean. The unit is set at the factory at 20dB of gain which is perfect for most instruments. If you have weaker pickups or want to push the envelope turn it up to its max gain 26dB."

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

Works well doesn't it. Well, I've built a couple of these and I love the tone they provide. I can fully recommend the circuit for anyone who needs a quick and easy compressor. The DIY project has been available for a few years now and was provided by the great Bajaman over at freestompboxes.org, here is the schematic and PCB layout files:

PCB Layout:

PCB Transfer:

So there you go - one of the best compressor pedals out there. I will say many people have asked about the VTL5C10; you've got to use it or at least construct your own optocoupler that matches it's specs.

Bajaman liked the circuit so much he based his own design around it with the Bajaman Optical Limiter, here's the schematic - LA2A style optical limiter:

Here's what he says regarding the optocoupler: "The LEDs used are both standard yellow 5 mm types. the LDR has a resistance of about 90 ohms when exposed to the light - sorry I cannot give you the exact number for this part but i found by purchasing from a number of suppliers that there are two common types in this size (5mm circular with top and bottom sliced off). You can test with a multimeter across the terminals - expose it to sunlight and observe the reading - if it is 350 ohms or higher, then you have the wrong type for this project - it should read around 90 ohms."

And a PCB layout:

And a PCB Transfer:

Limiters and compressor, although similar, do not function in the same manner. A limiter will only limit the peak of the wave and won't increase sustain as a compressor will. This is due to the way the envelope follower is configured. Notice that with the compressor the envelope is taken from the end of the circuit (A feedback config) whereas with the limiter the signal is taken from in front of the attenuation circuit (A feed-forward config). This difference may seem trivial but you need to take into account that the feedback config is effectively reacting to it's own changes. I.e - the envelope follower detects a strong sound wave, it decreases gain in the circuit, as the wave strength falls over time the envelope follower detects this and therefore forces the gain in the circuit to rise, the envelope follower then detects this rise and forces the gain back down and so on and so forth. It is this "feedback" action that gives the illusion of increased natural sustain. In a limiter there is no reaction or feedback effect, the circuit simply sees the strong first peak of the wave and attenuates, once the signal drops below the trigger voltage for attenuation to occur the envelope follower is essentially off. Therefore with the limiter you don't get the pseudo increase in sustain.

For reference here's the freestompboxes.org forum topic: http://freestompboxes.org/viewtopic.php?f=7&t=317

Friday, 27 January 2012

Dunlop - Eric Johnson Signature Fuzz Face

Well, Dunlop have just issued the Eric Johnson Signature Fuzz Face - it's supposed to give you those "violin" like sustain tones that Eric Johnson is renown for using. Looky at this video for more info (Also, check out that guy's beard - work of art.):

It's basically the same old Fuzz Face formula with these values in place:

But before you go and build yourself one up I'd read the freestomboxes thread. Marc Alfs of Skreddy and Mr Huge of Way Huge have chimed in and they're well on the way to coming up with some really nice stuff. Check the thread out here: http://www.freestompboxes.org/viewtopic.php?f=7&t=15839

MI Audio - Crunch Box

Only joking; here's the real MI Audio Crunch Box:

And here's an internal shot:

The MI Audio Crunch Box is a high gain distortion BeAsT! MI Audio make some great pedals and this is one of their most popular designs. It's schematic has been out on the DIY scene for a while but I still get the odd request for it so I thought I'd upload a project for you....

Here's the MI Audio website description of the Crunch Box (I know - it's an image!):

And the ProGuitarShop video of the Crunch Box in action:

Any how, onto the goods. There are two versions of the Crunch Box schematic a V1 schematic from an early model and a V2 schematic from a later model. Here they both are:

As you can see there are a few changes and the V2 circuit has the internal presence control that is mentioned in the MI Audio description. You could say that the Crunch Box is based on the Marshall Guv'nor without the 3 band tonestack (As is similar with the Lovepedal Superlead):

Here's a vero layout and a tagboard layout for the Crunch Box:

(Thanks to Sinner of http://www.turretboard.org for this one!)
Here's a PCB Layout for the Crunch Box: http://www.box.com/s/0xii4uivpp2nxbx1pkzl

Here's the freestompboxes.org forum topic for reference: http://freestompboxes.org/viewtopic.php?f=7&t=221

Thursday, 26 January 2012

OKKO - Diablo Boost+

Here's another personal favourite of mine. I just love those ridiculously sized LEDs! Anyway, the OKKO Diablo Boost + was donated to the freestompboxes forum anonymously. It's a great sounding overdrive/booster that when combined with the extra "+" knob can venture into some pretty high gain territory.

Here's a description from the OKKO website:

"The Diablo is a versatile low to medium gain overdrive with an exceptionally dynamic response. It preserves the character of your instruments and is very sensitive to your playing technique. Thanks to the effective and musical controls, the Diablo works equally well with any kind of guitar,  amp or playing style. People use it for so many different sounds, you would hardly believe that they use the same pedal.
Besides the usual Gain, Tone and Level knobs, the Diablo has some more interesting controls:
FEED affects the amount of bass in the input signal. You know the problem: an overdrive sound gets muddy rapidly if the input signal is too bass heavy (that’s why the treble booster was invented). With the FEED control you can make even the fattest neck humbucker sound clear and transparent or beef up weak pickups a little.
The BODY control takes effect on mids and compression. Another important feature is the HEADROOM SWITCH. Set to the "HI" position, an internal electronic voltage doubler is activated – the Diablo runs on 18 Volts from a regular 9 V battery or power supply. The higher voltage gives more dynamic range, more headroom and tighter bass – just try it!"

And  a demo video of the Diablo in action:

Here's a PDF of the OKKO Diablo schematic file: http://www.box.com/s/qz7r3bgncl3jzgugoe3e

As you can see if you look at the PDF schematic it compares very similarly to this, an old design by Jack Orman:

There's no doubt the Microbooster formula sounds great - there are so many pedals now using them in a cascaded structure - The Catalinbread Dirty Little Secret and Formula No 5, the OKKO Dominator and so on.

Harald Sabro (www.Sabrotone.com) has produced some brilliant verified vero layouts and posted them up on the freestompboxes forums:

Now, those veros don't include the voltage doubler that the original Diablo contains, so if you need to build one of these: 

Then all you need to add is a simple switch which will allow you to go between +9v and ~+18v...

Here's a link to the freestompboxes.org forum topic for reference: http://freestompboxes.org/viewtopic.php?f=7&t=1482

Zvex - Super Duper

[images of custom shop Super Duper 2 in 1 pedals - how cool is the butterfly?]

Here's a project I'm adding just because I get a lot of requests for the schematic - it's the Zvex Super-Duper-2-in-1. Basically two cascaded Super Hard on circuits with a master volume control at the end.

Here's an internal gutshot of the Super Duper [Note the extra transistors for Millenium bypass switching/polarity protection]:

Here's the description from the Zvex website:
"The SUPER-DUPER 2-IN-1 (TM) has two of my infamous but rather delightful Super Hard-On(TM) pedals in one small box, with two switches and LED indicators. HEY! I responded to your multitude of complaints that I don't put in LED's! Also, in this SUPER-DUPER 2-IN-1 (TM) (gosh I love saying that) is a Master volume control that lets you use it as an overdrive/distortion with any output volume. My my! How conventional, you say! Well, suffice to say, if it weren't there, you'd go deaf with both of those channels cranked up. This pedal is dangerously loud. Don't do what I did, and lean over in front of your speaker cabinet while turning it up. Ouch. Dang.


This channel is a conventional Super Hard-On (TM), which I will henceforth refer to as the SHO, in order to reduce potential offense to young ears and sensitive persons. Its gain control is on the far right, and it's LED is yellow. If you are familiar with the SHO, you'll know that it's a very sparkly sounding high input-impedance preamp with incredible headroom, wide-ranging gain (unity to 60 X), and a maximum volume that will knock out your fillings. Channel one has no Master Volume control, but it's cascaded into Channel 2, which does...


This channel has the very same circuit as Channel 1, but the bleeder resistor on the output has been replaced with a Master Volume control, which allows the user to turn down the output volume even if the gain is set quite high. The knob on the left is the gain, and the middle knob is the Master Volume, and the LED is red. When both channels are on, or if only Channel 2 is on, the Master Volume is active. If you leave the Master wide open, you have two identical SHO pedals in one box, which are cascaded."

Here's the ProGuitarShop demo video so you can see the Super Duper in action:

And here's a schematic for you:

If you want a layout, get yourself over to the Super Hard On project and just build two of those ;-) Or get yourself over the Madbean pedals and get a copy of his "FireBomb" project: http://madbeanpedals.com/projects/index.html

Here's the freestompboxes.org forum topic for reference: http://freestompboxes.org/viewtopic.php?f=7&t=696

Wednesday, 25 January 2012

Premier Guitar - The Ultimate Tube Screamer Mod Guide

Here's a great article by Dirk Wacker that has been online for a while over at http://www.premierguitar.com. It's basically a discussion of the most popular mods that can be performed on your good 'ole Tube Screamer - op amp changes, fatness mods, tone shifts, clipping options e.t.c. Here's the link, check it out: http://www.premierguitar.com/Magazine/Issue/2007/Jan/The_Ultimate_Tube_Screamer_Mod_Guide.aspx

Lovepedal - Englishman

Here's the Lovepedal Englishman, supposedly an emulation of the classic vintage Vox AC15 / AC30 amps while they're going through meltdown. It's been a popular pedal and it can't be denied that the demo videos do make this thing sound very pleasing.

Here's a more in depth description from the Lovepedal website:

"The ENGLISHMAN™ simulates the classic AC vintage amplifiers right before the amp fries. I have found these vintage amplifiers sound best CRANKED and on the verge of failure.

The unit will also enhance the sound of any amplifier without altering the tone of your guitar. The ENGLISHMAN™ has the ability to act as a super clean boost, semi clean boost, or with the volume & gain pushed higher it is capable of pushing any amp into beautiful harmonic breakup, overdrive and distortion.

With 3 modes of failure the “FAIL™” switch embarks new worlds of natural overdrive and downright amplifier distortion in a good way.

It flat out screams if you want it to or not. Just like the original English amplifiers of a time gone by."

Here's the ProGuitarShop demo video of the Englishman in action:

[R.E.M! I love R.E.M!]

Sounds nice doesn't it. Well, good news - some good fellow has provided freestompboxes.org with a traced project, so now we can build our own rather than pay the ridiculous after market price.

Here's the goods:

As you can see from the bottom picture the Englishman had to have some minor surgery on the way, but here's the schematic [NOTE - One slight mistake - the diodes marked 1N9148 should read 1N4148 (Although you can use 1N914)]:

As you can see from the schematic it's pretty much what's standard with Lovepedal - transistor booster with post gain diode clipping to ground. It differs slightly from his COT 50 designs with a slightly different bias on the transistor and larger input/output caps but that's about it really. The design is based mainly around the old Electro Harmonix LPB-1 Booster, here's the original schematic:

Here's the freestompboxes.org forum topic for reference: http://www.freestompboxes.org/viewtopic.php?f=7&t=15940

Lovepedal Englishman in for Minor Surgery

There's been an anonymous donation to the freestompboxes forum - the Lovepedal Englishman. There's a preliminary schematic along with some pcb images up in the thread here: http://freestompboxes.org/viewtopic.php?f=7&t=15940

So far it's a basic transistor buffer with a diode switch....

I'll be putting up a full project when we're verified ;-)