Tone chasers, knob turners, muff fanatics, lend me your ears: I come to bury the big muff, not to praise it!!! 
Jokes aside, I present to you the definitive best Big Muff. Which one, you ask? Why, all of them, of course !! Perhaps, your dream come true!
The Dazatronyx Big Fuzz console by Darron Thornbury from down under
. Included all the original bells and whistles including box, a lovely bag/slip cover, and a nice Dazatronyx branded pick.
Trades preferred. Rare broughtons preferred, such as a Super Watt*, Mastering EQ, or plenty others I’d accept.
In his own words:
This is the deepest muff dive that you're ever going down. I've built this project as a development tool to sculpt classic and custom muffs. Breadboards are one of the best ways to innovate and quickly try ideas. But being able to instantly A/B/C different parts in a rock-solid giggable box is the holy grail for me.
This tool takes all of the parts which varied in the classic muff designs, and makes them switchable. Mix and match as you like to design your own ultimate muffs. Hot swap transistors to test on the fly. Being able to sculpt the shape and scoop of your tone control is a very powerful thing. As well as changing the bass responses in the clipping stages. The circuit is completely analog with only mechanical switching.
Think you've got a special ear for tone? Your best-ever version muff is in here. You'll need to find it. Rather than trying to design pedals for people, I would rather hear back from people what they have been able to make for themselves.
Hunter Kegan has made a thoughful quick-reference diagram available for free download on his website: Bipolar Recorder.
How do I use this thing?
The good news is: there are no bad or wrong settings to begin with. So the more that you fiddle, and listen, the better suited it can become to your own, unique, ideal muff tone.
The part numbers match the original muff circuits, so you can find your favourite historic builds on websites like bigmuffpage.com, read up on any additional notes, and then find the best-matched values. Here is a link to a simplified schematic of the build to follow.
The signal flows through the pedal from right-to-left, with the controls grouped together in five sections progressing accordingly. The progression is:
Transistor stage 1 - gain boost.
Transistor stage 2 - 1st gain boost with diode clipping.
Transistor stage 3 - 2nd gain boost with diode clipping.
Passive tone control stage - Blends a high-cut and a low-cut as a high/low control.
Transistor stage 4 - final volume boost before the volume knob.
A note on the parts selections
Most of the controls allow for three selections, or more. With this limitation, I have selected values which are most-commonly occurring, so that you should be able to "dial in" almost any transistor muff version, or get practically close to it. Especially considering part variations, tolerances, and drift over time. In some instances, however, the parts were chosen to give a wider use of practical differences.
For example, many muffs used 100Ω emitter resistors. And many also used 120Ω, or 150Ω. Similarly, for many of the bypass/low-pass capacitors, a 1μF capacitor will do the same practical job as any other all-passing capacitor such as 0.68μF, or 3.3μF.
Transistors
For each of the 4 transistors, the are 6 device selection options. There are internal screw-terminal sockets to experiment with finding your own NPN transistors to install and test. Units are sent out with metal-can (TO-18 package) 2N2222A installed in the sockets. Using that, you could even try installing a germanium-silicon hybrid combination. Particularly with germanium in Q2 and Q3.
The transistor selections are of commonly suggested devices, along with their higher and lower gain bracket counterparts. BC547B / BC547C, 2N5088 / 2N5089, etc. BC337-25 is useful for V1 circuits.
Clipping (capacitors)
The Clip switches are an interesting place to start. These control how much bass is clipped by the clipping diodes. 47n clips the low-end frequencies less than 100n, resulting in more bass volume and body clarity left over. 100n gives a flatter tonal compression. 100n is the most-commonly used value.
Clip 1 is first in the signal, and help defines the boominess of the fuzz. Clip 2 later in the signal has more influence on the final tonal volumes. The Soviet versions famously stood out partly because they used 47n for both clipping positions, allowing for the most bass clarity and body.
The 1973 Colorsound Supa Tone Bender used no clipping diodes in the first stage, and 100n in the second.
There are no other diodeoptions, as most circuit versions can be recommended to be built with 1N914/1N4148 small signal silicon diodes. The line had to be drawn somewhere.
Tone control
The low-high style tone control on a muff circuit can be famously love-hate, and was a large contributing factor to the tonal variations between the many models. All of the tone control options are sectioned together, between Stage 3 and Stage 4.
With the TS HPF (Tone stack high pass filter) capacitor C9, starting with 10n will give a flatter tone control. As you rotate left to lower value capacitors, you really start to hear the signature muff-flavoured mid scoop get more pronounced. 4n is a commonly used value to try.
The Scoop control (R5) reduces the depth of the tone control scoop. Since the scoop is usually mids-heavy, it works to flatten that mid scoop back out. Most classic models used a lower value here such as 22K, or even 10K. Increasing this is more of a suggested optional mod. Balance this with TS HPF (C9).
10n was a common value for the TS LPF (Tone stack low pass filter) capacitor C8.
TS LPF (Tone stack low pass filter) resistor R8 commonly used values from 22K through to 39K.
Duncan Tone Stack Calculator is some classic software to help design and visualise the EQ curve.
Boost and gain stages
As the transistors used varied, so too did their supporting passive components.
The Emitter resistors (R22, R21, R10, R4) can be thought of as "gain-setting" resistors here, which changed to match the transistor selection. The lower the resistor value, the higher the gain at that stage. Often all of the first three stages had the same value emitter resistor. The last emitter Em 4 (R4) determines final output volume.
Collector resistors (R13, R18, R11, R6) change the boost nature, and also affect bias. Generally, a lower value performs neater, where higher values have a little bit more of a transistor-distortion nature to the fuzz character. Using an extremely large value here for stage 1 (Q4) can be helpul get a sound like the V1 muffs.
HPF (high pass filter) capacitors C1, C4, C5, C13, C3, C2 connect the audio signal between stages, while blocking DC voltage. The larger the capacitor value, the more that lower frequencies are allowed to pass. Smaller values can reduce bass, and tighten the fuzz character. These were commonly 100n throughout the circuit. Try 1μF everywhere for bass.
Miller capacitors (C10, C12, C11) smooth out high frequencies and reduce the harshness of the fuzz character. A lower value of 470p leaves more clarity and brightness, where 560p is warmer and smoother. 500p was often used, and may be the Goldilocks in the middle. Generally when building fuzzes, are larger value may be selected when more gain is used, to remove some shrillness. It's a very subtle, but still noteworthy difference.
Impedance resistors (R2, R19, R12) can be thought of as "loading" the signal, making it less strong, but not necessarily by simply lowering the voltage/volume so much. This influences the interaction between the signal and how the transistor can amplify it. A lower value resistance allows for more top-end clarity, or sharpness. Think more-'hi-fi' sounding. Higher resistance can make the fuzz nature smoother and more pleasant, while also reduces overall boosting slightly.
Bias resistors (R9, R17, R15, R7) set where the signal will swing within the transistor's operating voltage, to make best use of the available "headroom".
Buffers
It is often said that muffs sound best when following a buffer. Unlike many other classic fuzzes, the muff doesn't necessarily needto plug directly into the instrument to perform at its best. Leave the Buffer In switch off for a classical sound, or turn it on for a bit more clarity and edge. Buffers will also change how the instrument volume knob interacts with the fuzz tonally.
Bright Sweep (mod)
This is a mod which I use in the small Big Fuzz model. It's a small-value capacitor across the sustain pot which allows a little bit of top-end to bleed across, and not have the sweep become so dark in the low settings. Middle position turns this subtle mod off.
Jokes aside, I present to you the definitive best Big Muff. Which one, you ask? Why, all of them, of course !! Perhaps, your dream come true!
The Dazatronyx Big Fuzz console by Darron Thornbury from down under
. Included all the original bells and whistles including box, a lovely bag/slip cover, and a nice Dazatronyx branded pick.Trades preferred. Rare broughtons preferred, such as a Super Watt*, Mastering EQ, or plenty others I’d accept.
In his own words:
This is the deepest muff dive that you're ever going down. I've built this project as a development tool to sculpt classic and custom muffs. Breadboards are one of the best ways to innovate and quickly try ideas. But being able to instantly A/B/C different parts in a rock-solid giggable box is the holy grail for me.
This tool takes all of the parts which varied in the classic muff designs, and makes them switchable. Mix and match as you like to design your own ultimate muffs. Hot swap transistors to test on the fly. Being able to sculpt the shape and scoop of your tone control is a very powerful thing. As well as changing the bass responses in the clipping stages. The circuit is completely analog with only mechanical switching.
Think you've got a special ear for tone? Your best-ever version muff is in here. You'll need to find it. Rather than trying to design pedals for people, I would rather hear back from people what they have been able to make for themselves.
Hunter Kegan has made a thoughful quick-reference diagram available for free download on his website: Bipolar Recorder.
How do I use this thing?
The good news is: there are no bad or wrong settings to begin with. So the more that you fiddle, and listen, the better suited it can become to your own, unique, ideal muff tone.
The part numbers match the original muff circuits, so you can find your favourite historic builds on websites like bigmuffpage.com, read up on any additional notes, and then find the best-matched values. Here is a link to a simplified schematic of the build to follow.
The signal flows through the pedal from right-to-left, with the controls grouped together in five sections progressing accordingly. The progression is:
Transistor stage 1 - gain boost.
Transistor stage 2 - 1st gain boost with diode clipping.
Transistor stage 3 - 2nd gain boost with diode clipping.
Passive tone control stage - Blends a high-cut and a low-cut as a high/low control.
Transistor stage 4 - final volume boost before the volume knob.
A note on the parts selections
Most of the controls allow for three selections, or more. With this limitation, I have selected values which are most-commonly occurring, so that you should be able to "dial in" almost any transistor muff version, or get practically close to it. Especially considering part variations, tolerances, and drift over time. In some instances, however, the parts were chosen to give a wider use of practical differences.
For example, many muffs used 100Ω emitter resistors. And many also used 120Ω, or 150Ω. Similarly, for many of the bypass/low-pass capacitors, a 1μF capacitor will do the same practical job as any other all-passing capacitor such as 0.68μF, or 3.3μF.
Transistors
For each of the 4 transistors, the are 6 device selection options. There are internal screw-terminal sockets to experiment with finding your own NPN transistors to install and test. Units are sent out with metal-can (TO-18 package) 2N2222A installed in the sockets. Using that, you could even try installing a germanium-silicon hybrid combination. Particularly with germanium in Q2 and Q3.
The transistor selections are of commonly suggested devices, along with their higher and lower gain bracket counterparts. BC547B / BC547C, 2N5088 / 2N5089, etc. BC337-25 is useful for V1 circuits.
Clipping (capacitors)
The Clip switches are an interesting place to start. These control how much bass is clipped by the clipping diodes. 47n clips the low-end frequencies less than 100n, resulting in more bass volume and body clarity left over. 100n gives a flatter tonal compression. 100n is the most-commonly used value.
Clip 1 is first in the signal, and help defines the boominess of the fuzz. Clip 2 later in the signal has more influence on the final tonal volumes. The Soviet versions famously stood out partly because they used 47n for both clipping positions, allowing for the most bass clarity and body.
The 1973 Colorsound Supa Tone Bender used no clipping diodes in the first stage, and 100n in the second.
There are no other diodeoptions, as most circuit versions can be recommended to be built with 1N914/1N4148 small signal silicon diodes. The line had to be drawn somewhere.
Tone control
The low-high style tone control on a muff circuit can be famously love-hate, and was a large contributing factor to the tonal variations between the many models. All of the tone control options are sectioned together, between Stage 3 and Stage 4.
With the TS HPF (Tone stack high pass filter) capacitor C9, starting with 10n will give a flatter tone control. As you rotate left to lower value capacitors, you really start to hear the signature muff-flavoured mid scoop get more pronounced. 4n is a commonly used value to try.
The Scoop control (R5) reduces the depth of the tone control scoop. Since the scoop is usually mids-heavy, it works to flatten that mid scoop back out. Most classic models used a lower value here such as 22K, or even 10K. Increasing this is more of a suggested optional mod. Balance this with TS HPF (C9).
10n was a common value for the TS LPF (Tone stack low pass filter) capacitor C8.
TS LPF (Tone stack low pass filter) resistor R8 commonly used values from 22K through to 39K.
Duncan Tone Stack Calculator is some classic software to help design and visualise the EQ curve.
Boost and gain stages
As the transistors used varied, so too did their supporting passive components.
The Emitter resistors (R22, R21, R10, R4) can be thought of as "gain-setting" resistors here, which changed to match the transistor selection. The lower the resistor value, the higher the gain at that stage. Often all of the first three stages had the same value emitter resistor. The last emitter Em 4 (R4) determines final output volume.
Collector resistors (R13, R18, R11, R6) change the boost nature, and also affect bias. Generally, a lower value performs neater, where higher values have a little bit more of a transistor-distortion nature to the fuzz character. Using an extremely large value here for stage 1 (Q4) can be helpul get a sound like the V1 muffs.
HPF (high pass filter) capacitors C1, C4, C5, C13, C3, C2 connect the audio signal between stages, while blocking DC voltage. The larger the capacitor value, the more that lower frequencies are allowed to pass. Smaller values can reduce bass, and tighten the fuzz character. These were commonly 100n throughout the circuit. Try 1μF everywhere for bass.
Miller capacitors (C10, C12, C11) smooth out high frequencies and reduce the harshness of the fuzz character. A lower value of 470p leaves more clarity and brightness, where 560p is warmer and smoother. 500p was often used, and may be the Goldilocks in the middle. Generally when building fuzzes, are larger value may be selected when more gain is used, to remove some shrillness. It's a very subtle, but still noteworthy difference.
Impedance resistors (R2, R19, R12) can be thought of as "loading" the signal, making it less strong, but not necessarily by simply lowering the voltage/volume so much. This influences the interaction between the signal and how the transistor can amplify it. A lower value resistance allows for more top-end clarity, or sharpness. Think more-'hi-fi' sounding. Higher resistance can make the fuzz nature smoother and more pleasant, while also reduces overall boosting slightly.
Bias resistors (R9, R17, R15, R7) set where the signal will swing within the transistor's operating voltage, to make best use of the available "headroom".
Buffers
It is often said that muffs sound best when following a buffer. Unlike many other classic fuzzes, the muff doesn't necessarily needto plug directly into the instrument to perform at its best. Leave the Buffer In switch off for a classical sound, or turn it on for a bit more clarity and edge. Buffers will also change how the instrument volume knob interacts with the fuzz tonally.
Bright Sweep (mod)
This is a mod which I use in the small Big Fuzz model. It's a small-value capacitor across the sustain pot which allows a little bit of top-end to bleed across, and not have the sweep become so dark in the low settings. Middle position turns this subtle mod off.
