CONTEST Happy New Years Limited Parts Contest

CONTEST
Feral Feline said:
I collect bits 'n' bobs, so a quick check on my HD gave up this:

View attachment 67997

DON'T RECALL where it came from and there's no notes on the diagram itself. According to the HD info, I snagged it off the net this past November (28th) 2023.


I was going to post the above a couple days ago, did some more digging and most likely the above came from here:

Messenger Fuzz

Messenger Fuzz
www.handmades.com.br
Click to expand...
That can't be right. C5 kills all of the mids & treble.
 
Chuck D. Bones said:
That can't be right. C5 kills all of the mids & treble.
Click to expand...
Yes, that schematic isn't faithful to actual builds. It's based on someone's conjecture that the inductor in the schematic would be a standard wah inductor (based on photos of actual boards this is false). That person attempted to recreate the response curve of a wah inductor using a 100mh inductor and a capacitor.

I did some more research on this Fuzz, but I didn't find any information on the value of the inductor. So, I decided to assume that this is a common value in wah-wahs, 500mH, and I set up the circuit on the Proteus to see what the response would be like.
Click to expand...
As you can see, it is very focused on the midrange, and gradually cuts the treble range.
However, for a setup like my layout, it would be difficult to fit a wah-wah inductor, which are normally quite large, not to mention the price. With that, I decided to try using a more common inductor value (100uH), together with a capacitor, to create a filter with a similar curve.

I arrived at the following result, through trial and error
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From the Portuguese forum.
 
I took another hard look at the low-res photos and concluded that the mystery component is most likely an inductor. Can't be much more than 1mH based on size. LTSpice analysis says that a 1mH inductor doesn't do shit all the way up into the MHz region. I breadboarded your circuit with a Ge diode in place of the inductor and obtained decent results. However, that diode severely reduces the bias in Q1 (I'm docking you one point for not providing ref des on your schematic ;) ). The low collector current reduces the gain in Q1 down to a couple of dB. That's why it fixed the motorboating problem. I kept the Ge diode on my breadboard and increased the 47K (no ref des 😡) to 62K in order to get the gain back up to where it would be with no diode. I really like the tone, even though it doesn't sound like the Basic Audio Messenger Fuzz demo.

Just for clarification, your mods are:
  1. Deleting the 4.7K resistor up front
  2. Adding the DEPTH circuit
  3. Adding the GATE pot
  4. Adding the Ge diode
  5. Increasing the cap just before the volume pot
Did I get that right? Anything else?
 
Chuck D. Bones said:
I took another hard look at the low-res photos and concluded that the mystery component is most likely an inductor. Can't be much more than 1mH based on size. LTSpice analysis says that a 1mH inductor doesn't do shit all the way up into the MHz region. I breadboarded your circuit with a Ge diode in place of the inductor and obtained decent results. However, that diode severely reduces the bias in Q1 (I'm docking you one point for not providing ref des on your schematic ;) ). The low collector current reduces the gain in Q1 down to a couple of dB. That's why it fixed the motorboating problem. I kept the Ge diode on my breadboard and increased the 47K (no ref des 😡) to 62K in order to get the gain back up to where it would be with no diode. I really like the tone, even though it doesn't sound like the Basic Audio Messenger Fuzz demo.

Just for clarification, your mods are:
  1. Deleting the 4.7K resistor up front
  2. Adding the DEPTH circuit
  3. Adding the GATE pot
  4. Adding the Ge diode
  5. Increasing the cap just before the volume pot
Did I get that right? Anything else?
Click to expand...
Fair point about ref des - that should become a habit even when handwriting when sharing schematics.

Those mods are just about right. For my own build I've gone further and added a buffered voltage source and pickup simulator - haven't gotten the boards made yet. That goes outside the bounds of this contest. Without those elements here's what I have:

Untitled 5_page_1.jpeg
 
t1redhands said:
Fair point about ref des - that should become a habit even when handwriting when sharing schematics.
Click to expand...
You could also add an arrow or a dot indicating potentiometer CW orientation. With VOL it's obvious (probalby). Fortunately, in the case of DEPTH and GATE it doesn't matter that much, but with the marker there will be no doubts :)
Not only in this schematic, but in general, with hand-drawn ones.
 
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I realized earlier that I never shared a picture of the breadboarded circuit. There's a pcb layout in the works that I need to finish. I've been a little preoccupied.

fireballbreadboard.jpg
 
Hi everyone!

The judges have finally come together and have chosen a winner! All contestants entries have been breadboarded and judged! In the end there were 3 circuits that stood out to us, each with its own strengths and weaknesses.

The three finalists were...
@BuddytheReow Sho Yo Muff
@PedalBuilder Hybrid Mk II Tonebender
@t1redhands Messenger Fuzz

Each circuit had great tone and an answer to the others' compromises, but in the end there could only be one winner!

The winner is…… @BuddytheReow with the Sho Yo Muff circuit! Congratulations Sandy! Your originality was the deciding factor when it came to choosing the winner!
 
Big congrats @BuddytheReow !

I could certainly learn a few things from you about getting stuff done— over the course of this contest you churned out more than a handful of intriguing circuits (all of which I saved so I can remember to try them out down the road). Lots of really creative circuits you came up with. Definitely a well-deserved win!
 
Hope you all had fun trying something new! If you ever ask yourself “What would happen if…?” in this hobby, then you should DEFINITELY do that. You may be surprised what you come up with, but not every time. Sometimes it’s crap. Either way write it down for your future self.
 
I should also mention that today is my birthday. Nothing super special happened today, and that’s ok. Our family calls it birthday month since my brother and father-in-law also have birthdays this month so every weekend there’s another get-together. This was a nice surprise
 
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