# Big Muff Pi permanent tone bypass



## bifurcation (Apr 10, 2021)

Just checking my math here...

If I wanted to build a (louder) always-tone-bypassed two-knob big muff, would I just bridge from Q3 past C12, or would I leave C12 in the circuit?


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## Robert (Apr 10, 2021)

You'll want to leave C12 in the circuit, otherwise Q3 will affect the bias of Q4.


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## bifurcation (Apr 10, 2021)

Robert said:


> You'll want to leave C12 in the circuit, otherwise Q3 will affect the bias of Q4.


Thanks! I wondered, but second guessed myself.


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## skrattadu (Apr 11, 2021)

Check out the schematic for the BYOC Big Muff Clone, it adds a switch for the tone control bypass.
largebeaverramsinstructions (byocelectronics.com)


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## bifurcation (Apr 11, 2021)

skrattadu said:


> Check out the schematic for the BYOC Big Muff Clone, it adds a switch for the tone control bypass.
> largebeaverramsinstructions (byocelectronics.com)


Thanks 

The Dream Fuzz has a tone bypass too!


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## almondcity (Sep 9, 2021)

gonna resurrect this thread, re: adding a tone bypass switch to Big Muff

can someone explain how exactly to go about this?  I understand schematically what needs to happen with the switch, but how to physically implement it is the part I don't understand


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## BuddytheReow (Sep 9, 2021)

You'll need to put a jumper wire between Q3 collector and C12. Depending how the PCB is laid out it may be at either C10 or R17 instead of Q3 collector. Use you DMM on continuity setting to check where the circuit goes at those 2 points relative to Q3.


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## Matmosphere (Sep 9, 2021)

Kit Rae has the tone wicker muff schematic on his page too.
Just a suggestion but you could do an internal trimmer turned all the way down instead, that way you’d still have the option if you ever want it down the road.


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## Big Monk (Sep 9, 2021)

I always thought tweaking the Tone control on the Muff a better option than bypassing it. Frankly, does the Big Muff need more gain?!


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## BuddytheReow (Sep 9, 2021)

Let's take a step back. @almondcity what are you trying to accomplish? Just more volume? Merely having no tone control? Which version are you building?

If you just want more volume/gain you can lower R22 value. Socket it of course.


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## almondcity (Sep 9, 2021)

I'm considering adding a tone bypass switch to remove it from the circuit


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## BuddytheReow (Sep 9, 2021)

Ah, ok. Here's a helpful link





						AMZ - Guitar Effects: Tone Control Bypass
					

Bypassing the Big Muff Pi tone control.




					www.muzique.com
				




You'll need to put in a DPDT switch. Negative end of C11 should go to pin 2, the "ground" end of R18 should go to pin 5. Pins 1 and 4 should connect to the pads on the PCB. Those go to ground. Pins 3 and 6 should remain open. Per the link: "Flipping the switch to the other side lifts the ground connection on the two components and the tone control is effectively bypassed."

Sorry about that. I was looking at the OP and not your post


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## Big Monk (Sep 9, 2021)

almondcity said:


> I'm considering adding a tone bypass switch to remove it from the circuit



Our questions and considerations revolve around the "why" of what you are doing, not the "what".

What are you trying to achieve?


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## almondcity (Sep 9, 2021)

Isn't tone bypass is a common mod for big muff?


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## BuddytheReow (Sep 9, 2021)

almondcity said:


> Isn't tone bypass is a common mod for big muff?


The Big Muff is a _highly _modded circuit in the DIY community. Take a look at the build doc: there are *9 *separate circuits you can make with the same PCB layout and by only changing the values of certain parts.

Are you merely trying to make a 'modded' pedal to say you modded it?


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## Coda (Sep 9, 2021)

BuddytheReow said:


> The Big Muff is a _highly _modded circuit in the DIY community. Take a look at the build doc: there are *9 *separate circuits you can make with the same PCB layout and by only changing the values of certain parts.
> 
> Are you merely trying to make a 'modded' pedal to say you modded it?


There are tons more versions possible with the pcb and a careful translation of the PedalPCB schematic and the versions listed by Kit Rae.

To me, a muff without the muff tone stack is less a muff. My go-to muff mod would be to boost the mods a bit…but even then you risk loosing the muff magic.


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## BuddytheReow (Sep 9, 2021)

After I read my post it came across as a bit rude. One of my first pedals I modded it just to say I modded it. I wasn’t truly happy with the result but I kept it.

personally, I like the BMP tone stack given its versatility. Others don’t like it


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## almondcity (Sep 9, 2021)

I've built 4 Big Muffs for myself but I ended up ordering 2 more boards and want to try something new, the 2nd is going to a friend and will just build a standard one

Have I lost my mind?  Possibly


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## Coda (Sep 9, 2021)

almondcity said:


> I've built 4 Big Muffs for myself but I ended up ordering 2 more boards and want to try something new, the 2nd is going to a friend and will just build a standard one
> 
> Have I lost my mind?  Possibly


Sounds like the Muff Madness to me…


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## Big Monk (Sep 9, 2021)

almondcity said:


> Isn't tone bypass is a common mod for big muff?



It is. I guess we are just curious as to the “why”.

Bypassing the tone stack will increase the gain and remove the mid-scoop. I’ve always thought the Big Muff has TOO much gain, so adding more to alleviate the mid-scoop is like cutting off your nose to spite your face.

A mid switch is probably a better choice than full bypass. That way you can have a scooped, flat, and boosted mods mode.


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## Bricksnbeatles (Sep 9, 2021)

almondcity said:


> I've built 4 Big Muffs for myself but I ended up ordering 2 more boards and want to try something new, the 2nd is going to a friend and will just build a standard one
> 
> Have I lost my mind?  Possibly


You’ve probably lost your mind, but as long as you haven’t lost as much of your mind as I have, you should be fine!


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## Feral Feline (Oct 1, 2021)

Nothing wrong with bypassing the tone stack semi-permanently: add a 150k resistor and you won't get the volume jump (150k is what EHX used/uses for its own tone-bypass mod).

You could make that resistor variable as a trimmer or external and make the tone bypass switch a stomper.

Go for it!


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## thesmokingman (Oct 7, 2021)

I 've done the hard tone bypass before as part of a larger set of mods ... was unprepared for the results, definitely not the same as the tone bypass switching on the old op amp muff


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