Muffinator Fuzz Question

G

greypilgrim76

New member
Hi All,

I've been lurking in the forum for a while and learning a lot from all of you as I start my pedal building. I've done StewMac kits up to this point, but I recently ordered some PCBs from this site to start taking (at least some of) the training wheels off the process. I've been putting together a parts order, and everything seems to make pretty clear sense, except for the Muffinator Fuzz. the PCB doesn't appear to have the specific components identified on the board itself the way some of the others do, and on the Muffinator page, it says that the build documents are coming soon. It also says that the Muffinator is "identical to the Muffin Fuzz, with the addition of switchable diodes in each clipping stage."

The issue I'm seeing, though, is that there are spots for components on the Muffinator PCB that aren't listed in the build doc for the Muffin Fuzz. Specifically, I'm looking at this list of components in the Muffin build doc:

Screenshot 2025-07-22 at 5.58.33 PM.png
So in this document, the resistors run from R1 to R24 (plus the RLED slot), the capacitors from C1 to C15, etc. When I look at the Muffinator PCB, though, I see some discrepancies. Here's the PCB image:

Muffinator.png So, here are the difference I'm noting:

-No spot in the Muffinator for R24
-No spot in the Muffinator for C15
-No components listed on the Muffin sheet for D5–D8

Since I haven't done this sort of thing before, I just want to double-check how to handle these differences. For the first two, am I good to just leave those components out? For the third, do I just need to pick some diodes? If so, what are those four additional diodes doing in this circuit? Are they the two sets of switchable diodes? If so, I'm assuming D5 and D6 should be a matching pair and the same for D7 & D8? And if I'm right about that, does anyone have recommendations?

Also, there are two spots for SPDT switches. I'm assuming these are for the switchable diodes, but what does each switch do specifically? And should they be ON/ON or ON/OFF/ON?

Finally, any issues you suspect I'll run into that I don't seem to be aware of?

Sorry for the noobish questions. I tried to find as many answers as I could before posting, but there's just enough lack of clarity here that I don't want to screw it up. Any help is much appreciated! (As is all the help you've already provided without knowing it!)

Thanks!

PS--Any recommendations for this build as far as choosing between the different options in the Muffin Fuzz document? It looks like it's got slightly tailored builds for "Green Russian," "Civil War," "Triangle," "Chelsea," "Emanating Fist Dope Priest," "Bigger Muff," "SUF '75," and "SUF Mascis Muff." I'm generally familiar with some of these based on the "real" Muff pedals, but are there any that are particularly good for this build?
 
The build docs aren't up yet, so I'm making an educated guess:
  1. The "missing" R24 and C15 are probably just leftovers from a previous revision; They were removed from the circuit, but not from the BOM.
  2. D5-D8 are alternate clipping diodes that can be selected via the clip switches. This would be a "choose your own adventure" part. Put in something with a different forward voltage than the 1N914s, omit them for opamp clipping, or throw in some $5 diodes for extra mojo!
These are guesses. If you are not comfortable with this level of uncertainty, wait for someone more in-the-know to comment or for Robert to post the full build doc.

Good luck and godspeed!
 
Welcome! All good questions. There is so much info here. This is my response.

So R24 on the Muffin is for the tone bypass feature. Its for maintaining volume when bypass is switched on and off. It does mention that in the build doc IIRC. You can just not worry about C15 in the Muffinator.

The diodes are for the first and 2nd stages of clipping in the circuit. There are some great articles about the differences in stage 1 and stage 2. Basically different effect with the stage 1 close to the input and stage 2 closer to the output. This is super basic explanation.

Best suggestion is to socket those diodes. Mix and match. I've found so many sound different. And its very subjective. I went with 1n34a Ge, LEDs, 1N4148s. You don't necessarily need to match these diodes either.
 
Also, I've built all of the variants in the Muffin and I love them all. They all work great with build. Some subtle, some not so subtle. The '75 and the Triangle are good starters for new builders. Its really all subjective though.

Best advice i can give is the search function on the forum is super helpful. You can find so much with the right wording.

Here is an answer for the switches:

Post in thread 'Muffinator Fuzz Spdt switches ?' https://forum.pedalpcb.com/threads/muffinator-fuzz-spdt-switches.26351/post-337131
 
Last edited:
Aleph Null said:
The build docs aren't up yet, so I'm making an educated guess:
  1. The "missing" R24 and C15 are probably just leftovers from a previous revision; They were removed from the circuit, but not from the BOM.
  2. D5-D8 are alternate clipping diodes that can be selected via the clip switches. This would be a "choose your own adventure" part. Put in something with a different forward voltage than the 1N914s, omit them for opamp clipping, or throw in some $5 diodes for extra mojo!
These are guesses. If you are not comfortable with this level of uncertainty, wait for someone more in-the-know to comment or for Robert to post the full build doc.

Good luck and godspeed!
Click to expand...
You're right! I hadn't even thought to check the component list for the Muffin against the PCB, but those components are gone, so problem solved! :)
 
VanWhy said:
Welcome! All good questions. There is so much info here. This is my response.

So R24 on the Muffin is for the tone bypass feature. Its for maintaining volume when bypass is switched on and off. It does mention that in the build doc IIRC. You can just not worry about C15 in the Muffinator.

The diodes are for the first and 2nd stages of clipping in the circuit. There are some great articles about the differences in stage 1 and stage 2. Basically different effect with the stage 1 close to the input and stage 2 closer to the output. This is super basic explanation.

Best suggestion is to socket those diodes. Mix and match. I've found so many sound different. And its very subjective. I went with 1n34a Ge, LEDs, 1N4148s. You don't necessarily need to match these diodes either.
Click to expand...
This is all really helpful!

So am I right in guessing that, on the PCB for the Muffinator, the "CLIP1" switch will switch between the "stock" 1N914s in the D3/D4 slots and whatever alternate diodes I decided to put in the D5/D6 slots? And the same on the other side with "CLIP1", D1/D2, and D3/D4? And if I use an ON/OFF/ON switch in each location, the OFF position will bypass the diodes connected to that switch entirely for a different sound than either set of diodes? So, basically nine sound combos between the two switches?

I'm leaning toward maybe some Ge diodes for one position and LEDs for another--would one type of diode make more sense in the "CLIP1" vs "CLIP2" position than other types, or is it just down to taste? I'll definitely be using sockets to play around a bit one way or the other!
 
You are correct.

Ge needs to be low leakage or it'll neuter the gain. Schottky's (1N5817, etc) would give somewhat similar results without being so picky.

You might need to experiment because the same pair of diodes will sound different in each of the clipping stages.
 
One last question (for now, at least!): if I go with the Triangle build, it shows C2 as "N/A." Does that mean I just leave that capacitor out entirely? If so, I do need to jump that slot or do anything other than just leave it empty?
 
Just leave it empty. Any time one of my docs says N/A or OMIT, you just omit the component and do nothing.

If a component needs to be jumpered it will specifically say so. (Unless I messed up, which is never impossible)
 
greypilgrim76 said:
...

I'm leaning toward maybe some Ge diodes for one position and LEDs for another--would one type of diode make more sense in the "CLIP1" vs "CLIP2" position than other types, or is it just down to taste? I'll definitely be using sockets to play around a bit one way or the other!
Click to expand...
Definitely down to taste. Trust your ears.

The second clipping stage will have more impact on the overall tone, much like how where stacking two pedals the second pedal will be the dominant tone (or so I've read).

Here's a fun experiment:
Given that you're using sockets...
stick some Schottky in Switch1-Position1 and LEDs in Switch1-Position2.
stick the same combo in switch two but reversed LEDs Switch2-Position1 and Schottky Switch2-Position2.
That way it's easy to remember both switches up is one configuration and both switches down is the other.

See which order you prefer. The Schottky have a small fV and will compress the hell out of the signal, the LEDs have a high fV and allow for much more headroom before breakup — so it's easier to compare. Which sounds better to you? Compressed>Headroom or Headroom>compressed?

Maybe, though, that works for you with Schottky and LED, but you might prefer the opposite with Schottky and MOSFET-as-diode? Or Silicon vs JFET-as-diode? 🤷‍♂️


SUCH a rabbit-hole with just the diodes. Then start experimenting with all the different Muff variants from Kit Rae's website, which goes well beyond the abundance of choices in the Muffin doc ...
 
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