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Tonebender MkIII: circuit analysis

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 The Tonebender MkIII is finally quite close to  a Fuzz Face :  a first stage amplifies the signal, which in returns makes the last transistor saturates: here is the fuzz!  The main difference is that contrary to the Fuzz Face, the first stage is a 2 transistors amplification stage, and it amplifies the signal enough so you do not need a feedback loop to make it bigger. Lets see that in details. Here is the schematic of the Tonebender: And as usual, the schematic divided in functional parts: So, the first stage amplifies the signal, which then makes the Q3 transistor saturates. Then, there is the tone control stage to remove of bit of trebles and fizziness, and finally a volume output stage. Notice that  the circuit is in reverse polarity  because germanium PNP transistors are used here. Lets analyse each par one by one! The amplification stage The signal goes through a first C1 coupling capacitor, to avoid any parasitic DC current to go in the circuit. R1 and R2 form a voltage divider
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Dead Astronaut Chasm Reverb circuit analysis

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 Here is the circuit, from the build document: If you have already read the  circuit analysis of the Rub A Dub Reverb , you can already find some similarities. As most of the DIY reverbs, it uses a Belton Brick, an IC that allows DIYers to make reverbs without having to use a spring reverb tank. It is divided in several parts: Let's analyze each part of the circuit. Power supply The power supply is a classic one that we can find in many circuits. It provides 3 different regulated tensions:  9V, 4.5V and a regulated 5V. The Zener diode (D6) prevents polarity inversions. R22 and C16 forms a low pass filter that will eliminate any 50Hz parasitic voltage ripples remaining from your AC outlet. R23 and R24 forms a voltage divider that provides a 4.5V tension (VB) . It is regulated by C17, a 47uF capacitor that will absorb excess of voltage. This tension is necessary for the OP amps to operate correctly Then, there is a voltage regulator, REG1, that is a 7805. "78" means that th
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Klon Centaur mods and tweaks

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  Summary Klone centaur build (Aion refractor) Klon centaur circuit analysis Klon centaur mods and tweaks Klon centaur history and versions  Here is the schematic of the Klon Centaur: The Klon centaur circuit can be modded easily to modulate the gain, bass response or diode clipping. Lets see a few Klon Centaur mods together: Increase C14 value:  it is a very common mod to set the tone response a bit better. It allows a bit more bass to go through and make the Klon less "thin sounding". I usually use a 6.8nF capacitor, treble pot is thus more useable. Separate the dual gain potentiometer in two pots:  instead of using a double potentiometer, you can split each parameter with two 100k potentiometers. You can choose how much clean signal you will blend with the overdrive sound, or use only the overdrive part of the circuit. It is also useful for bass, if you want to let more bass goes through the circuit. I guess that the blend potentiometer on the bass soul food comes from thi
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Klon Centaur circuit analysis

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  Summary Klone centaur build (Aion refractor) Klon centaur circuit analysis Klon centaur mods and tweaks Klon centaur history and versions For those who do not know the Klon Centaur yet,  it is an overdrive created in the 90s by Bill Finnegan and MIT engineers  (yes!), that is probably the "hypest" pedals of all. It was used by many guitarists, including Jeff Beck for instance. It is a three potentiometers overdrive: gain, volume and trebles, famous for the light crunchy tones it provides to your sound. It has also an excellent reputation as a buffer or clean boost. In fact, I have already made  Klon buffer PCBs  to use it in a patch box.  The Klon is a rather complex circuit.  It is quite weird because there are lots of informations and tests about this pedal online, however there are few informations about how the circuit works precisely. I have to remind you that the circuit was mainly conceived by electronics engineers from the MIT (and not by Bill Finnegan, who tweaked
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Klon Centaur versions

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  Summary Klone centaur build (Aion refractor) Klon centaur circuit analysis Klon centaur mods and tweaks Klon centaur history and versions Aestheticaly, the enclosure design changed a bit around the production time. Lets do a bit of "klonology" (chronology, get it ?! OK, I'm out...) Gold and silver klons were produced at the same time, however the silver Klon was introduced in the early 2000s, and the graphics changed a bit with time. Three graphics can be considered: no centaur, big centaur with "open tail", and small centaur with closed tail. There were 5 different colors: 4 different gold colors (that you can see on the picture above), and the bare polished aluminium color (aka "silver" centaur). Around 8000 Klon centaurs were made between 1994 and 2009 according to Bill Finnegan (1.5 Klon centaur a day!). All those Klon worth today more than 12.000.000 euros! First,  there are no differences between gold and silver centaurs.  The circuit and compo
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Big Muff tonestack : dealing with mids frequencies

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 As you may know,  Big Muffs can be annoying because you loose a lot of medium frequencies when you use it , which as huge downside effect: you just disappear from the mix! It can be nice sometimes when you do not want to be heard too much (when heavy riffing with a singer, or to let your other guitarist do a solo...etc). However, when you want to solo, you are doomed to be silenced by the Muff! I advise you to read the  Big Muff circuit analysis first . Here we are going to see in detail a very important part of the Big Muff circuit that cause this effect:  the tonestack . The tonestack is a small part of the circuit, with 5 components , , that allows you to set the tone of the saturated signal, the amount of bass and trebles.  One of the characteristics of this tonestack is that it scoops the mids of your tone. It gives you a heavy, powerful tone. However, the huge downside to it is that  when playing in a band, you can easily disappear in the mix.  Indeed, the low frequencies are co
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Big Muff circuit analysis

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  The Big muff is one the favourite circuit of guitar pedal builders  (with the Tubescreamer). Indeed, its circuit is really well known, there is a lot of information available all around the internet, and it is really easy and fun to modify! Each component plays a particular role, and changing it for a different value will change the overall sound of the pedal without damaging the circuit most of the time. It is one of the most cloned guitar pedal, by DIYers or by boutique companies: Mojo Hand FX, Earthquaker Devices, Pete Cornish... Almost every brand has its version of the big muff! Attack of the clones: all the pedals in this picture are Big Muffs  or "heavily inspired" by the Big Muff pedal Technically the Big Muff is not a fuzz but a distortion with most of the saturation coming from diodes. However, it has 2 distortion stages, causing the heavily compressed and saturated sound of the Big Muff. The sound is finally close to a fuzz. Lets have a look on the circuit schema
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