What does it take to trace a PCB?

fuzz

Member
Hi All,
Apologies if this is a basic question that has been discussed ad nauseum, but being a noob at this sort of thing, I guess I have to ask to learn.

Long story short, I have a DBA Evil Filter pedal. Two things: Its f*ing massive, and I have no use for the fuzz side. What would it take to get the PCB traced so I could get a PCB or schematic of just the filter side of things? Complete disassembly and high res photo's? Send to someone who can do this sort of thing? I have no idea regarding the ethics of this ask, if it's in bad taste, or not and I can only assume "not really" as there are other DIY's of existing pedals being sold. But again, I am unclear and come from a place of curiosity
 
Welcome brother.

We here on the forum look down upon anybody who dares to learn how to connect various electrical components in an order that resembles any existing effect pedal on the market, and firmly believe that the power of the state should be used in as heavy-handed a way as possible in order to snuff out any such attempts. Because reverse-engineering is for communists and the disgusting, wreched poors who don't understand how important magic diodes are.

*Seizes, foams at the mouth*

Huh? What? Must've just come out of a fugue state. Anywho, welcome dude. We're a community that enjoys circuits designed by folks who often learned by copying other designs and seeks to make information available to those who want to build those circuits, learn in the process, and exercise some degree of pride in the little noise maker boxes that we slap together. Cause it feels good to make things.

Also, we like music. And as the old saw goes: good artists borrow. Great artists steal.

Tracing circuits is a bit of an undertaking. I've done a couple myself, but those have been remarkably simple.

It's a time consuming process, but in reality it doesn't require a *lot* of knowledge in regard to electronics, but knowledge and familiarity makes the process *much* easier.

All one really needs is a pair of eyes, a soldering iron, and a multimeter. The traces on single and double-sided circuit boards can often be seen with the naked eye. From there, one simply needs to be able to identify and discern the values of the components, understand how to read a data sheet and schematica, use a meter to confirm connections, and put the pieces together.

A complex circuit is generally not a good first try. Honestly, I think the best way to get started is to do something relatively simple. My first trace was a crybaby/vox-style wah pedal.

Drawing up a schematic is an art form in and of itself, honestly. There are ways to do so that make more sense (Robert's schematics are always remarkably straightforward) and less sense (some of the early DEFX schematics can be a PITA to dissect).

There are folks who will trace a circuit for ya. IIRC, Robert's been known to borrow pedals from folks on here and develop circuit boards for sale on the website from time to time. But each is a time-consuming process, and sometimes the juice just isn't worth the squeeze.

This is especially true of pedals that rely on parts that are out of production and there are no readily available replacements that can do the same job exist. Also...sometimes there just isn't enough interest to justify devoting the amount of time required to trace a board and produce a product.

Although, what I will say is that I'd build the hell out of an evil filter. But I'm the kind of weirdo that really likes DBA's offerings.

Other folks might do it...but I can't imagine it's a particularly cheap proposition. It's the sort of thing that would require a hell of a lot of trust on both sides of the transaction too: you'll be without your pedal for quite some time, likely, and there's always a possibility that whoever traces the circuit could accidently do something that would render your pedal bricked.

But, I don't want to dissuade you. It's a fun aspect of the hobby, just know that it's something that takes practice. Like playing the guitar.
 
If you could find a schematic online and post pics of both sides of the board I'm sure someone here would be able to help....

If not, someone will need to trace out the pedal itself who has a general knowledge of guitar circuits. An audio probe and DMM would be needed to translate into a schematic.
 
Already traced it. The filter side isn't a whole lot different from the Anderton Super Tone Control (ProFilter), aside from the fact that it uses an extremely overpriced and unnecessary filter IC. (UAF42AP, $23 each)

Are you wanting expression control as well?
yea, Ideally.
 
Let me see what I can come up with.... It's been sitting on my desktop for a few years needing to be finished.

I can probably fit the whole thing (fuzz and filter) in a 125B... definitely a 1590BB (might make more sense with the expression jack).
 
Man, I would love this in a 1590BB. I have zero need for the fuzz, is it possible to make that optional? Or modular for those who want the fuzz? I just dont think the evil filter fuzz sounds good.
 
OK, this should come together in a 1590BB fairly easily... I just need to work up a control layout of some sort.

I think I'm going to replace the filter selector rotary with a 3-position toggle switch, just to make the build a little easier.
 
OK, this should come together in a 1590BB fairly easily... I just need to work up a control layout of some sort.

I think I'm going to replace the filter selector rotary with a 3-position toggle switch, just to make the build a little easier.
Great idea. That rotary switch takes up a lot of space it seems
 
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