madbeanpedals::forum

Projects => How Do I? Beginner's Paradise. => Topic started by: jessenator on June 16, 2022, 06:26:30 PM

Title: Changing frequency filter caps…
Post by: jessenator on June 16, 2022, 06:26:30 PM
SO, I'm interesting in tinkering with modifying the filtration of the Super-Fuzz circuit and wondering a few things:
(https://i.imgur.com/8aa3uh6.png)
Are these two caps the main ones? From what I've searched, the filter is a bandpass, essentially making it a mid-scoop filter (at least it sounds like Metallica when I switch it on :P )

If I was to omit one of the caps, simply jumpering it, would I make it into a low/high pass depending on the values of the caps?

Could I modify it into more of a notch filter, where I'm boosting mids vs cutting them?

I'm pretty sold on the idea of replacing the switch with a pot to give more tonal control also, but generally I LIKE the circuit, I just don't like mid scooping, personally.


thanks

edit: I just realized this is my bad schematic lol. Yeah, the barrel jack for power has the poles swapped :|  just ignore that, I'll have to get a new board, I know, but just forgot about it.

edit 2: yeah, there's lots wrong with this schematic… it was my first, though. I hadn't figured out how to mirror drawings :S
Title: Re: Changing frequency filter caps…
Post by: jwin615 on September 01, 2022, 01:02:44 AM
To my eyes, looks like a modded bmp tone stack.
R24 c14 are low pass
C15, r23 are high pass
You should be able to modify.
See Duncan tone stack calc
You could do a pseudo mids knob hack and add a variable resistor (trimpot)in place/series of r23 and tune by ear. That would be a fast and easy experiment.
Maybe change r22 to 2k and add a 20k trimpot(or pot).
Or tie two legs of a pot together with a resistor (equaling ~44k combined, 22k ) and replace the resistor with that.
May have to modify the corner freq of the other filter stage though.
Give this one a readover.
https://www.coda-effects.com/p/big-muff-tonestack-dealing-with-mids.html?m=1
Title: Re: Changing frequency filter caps…
Post by: jessenator on September 01, 2022, 03:10:14 PM
Quote from: jwin615 on September 01, 2022, 01:02:44 AM
https://www.coda-effects.com/p/big-muff-tonestack-dealing-with-mids.html?m=1

Thanks for the input and link! I'll give it a look.
Title: Re: Changing frequency filter caps…
Post by: jwin615 on September 01, 2022, 11:11:29 PM
I think Wampler did a good yt vid on the bmp tone stack mids mod. Or maybe diyguitarpedala did. Or maybe both.