Circuit design 101

January 19, 2020 6:52 AM

I'd like to design / mod my own guitar pedals. How do I learn the basics of circuit design?

I recently built a fuzzface clone from a kit, and had a blast, plus I really like the way it sounds. Even though I managed to pull off the physical act of making a pedal (basically soldering and wiring up everything on a pre-made PCB), I have no idea why it sounds the way it sounds, why it uses those specific components, etc. I'd like to learn enough electronics to a) be able to read and understand a simple circuit diagram (like the one that came with the fuzzface kit) and b) sometime in the future, modify or create my own design.

I'm not looking for a comprehensive education, just enough for a hobbyist to know what they're doing.

Youtube videos, websites, books, all might work.

posted by signal to Technology (10 answers total)

Somebody's going to recommend The Art of Electronics, so I might as well go for it. It's one of the seminal reference books on circuit design, though more something you'd read in an EE course than light fun reading.

SparkFun's tutorials look pretty good. Adafruit's are too. I've used info from both at various points, although I grew up around circuit schematics so I can't actually remember learning that stuff for the first time (pretty sure my father taught me, though I don't specifically remember learning)!

I was really hoping there would be a "Fran Blanche (of Frantone) talks through one of her boards" video, since Fran does lots of electronics content on youtube and used to design pedals, but I wasn't able to find anything.

I'm not sure if there is too much detail here for a beginner, but I tried searching for "Big Muff Pi Circuit Analysis," (because that's a pedal I know, I'm sure the same exists for other popular pedals) and ended up here, which has a diagram and some analysis. It definitely jumps over the basics and right into "here's a bunch of words about analog electronics," but it might help you figure out other things you want to search out, if you're into putting together information.
posted by Alterscape at 7:56 AM on January 19, 2020 [2 favorites]

Oh, there's a less jargon-y Big Muff analysis here, actually. It's more my speed, for certain, as someone who knows digital logic from DIY, but never formally studied EE..
posted by Alterscape at 7:58 AM on January 19, 2020

Response by poster: The sparkfun tutorials seem too be about the speed I'm looking, for, at least for the reading schematics, thanks!
posted by signal at 8:36 AM on January 19, 2020 [1 favorite]

Geofex has been a good resource for quite a while. There are several forums for enthusiasts. Smallbear has been supplying parts exclusively for the diy market. That site has some good resources and links.

I don't know if there's a single resource that works well for everyone. Experimenting and reading everything I could get my hands on gave me a reasonable understanding of what's going on with these kinds of circuits.
posted by 2N2222 at 1:21 PM on January 19, 2020 [2 favorites]

I almost forgot, author R. M. Marston wrote prolifically for diy electronics publications and many books. I found his writing concise and easy to digest. Some of his articles can be found on Nuts and Volts site here. The articles most relevant are Bipolar Transistor Cookbook, OP Amp Cookbook, FET Principles and Circuits. The info is basically reprinted from his books on the subject, which are numerous though mostly out of print.
posted by 2N2222 at 1:44 PM on January 19, 2020

Seconding GeoFX & Smallbear.

Also, rather than create a whole new pile of links & whatever, Imma refer you to this previous answer of mine from another Ask, which is a pretty comprehensive list of sites and sources I've collected for pedal building & modding.

One thing to keep in mind is that an awful lot of pedals are really just variations on a theme - there are lot of pedals that are essentially FuzzFaces, or Big Muffs, or Ibanez Tube Screamers, or whatever, in their core circuitry, just with certain values tweaked or relatively minor elements added, like a tone control. So that can help as you start to poke through stuff, once you're aware of this you can start to see that this pedal & schematic are 90-95% the same as that pedal and schematic, and start to see patterns in common between multiple pedals.
posted by soundguy99 at 5:55 PM on January 19, 2020 [1 favorite]

The Craig Anderton book is what I used back in the day, and should still be relevant.
posted by doctord at 5:52 AM on January 20, 2020 [3 favorites]

Ooooh yeah, Craig Anderton. Plus he's written a bunch of columns and articles for magazines like Guitar Player and Electronic Musician, which I think you could probably find online to some extent.
posted by soundguy99 at 6:54 AM on January 20, 2020

I'm in a similar boat as you (Synth DIY instead of pedals) and one of the most useful things I found that helped my understanding of circuits was being able to implement things in a circuit simulator and then play around and see which components affect which aspects of the signal. This is the simulator I have been using http://www.falstad.com/circuit . It is very simple and straightforward to use, operates in realtime, and it can show you the flow of electrons and graph changes in voltage and current. You can even add sliders to control individual component values so you can easily see how changing them affects the total circuit's output.
posted by Television Name at 9:43 AM on January 21, 2020

Not really a how-to, but you might check out Fran Blanche's effects pedals. Her YouTube channel has a lot of electronics stuff, and there's a playlist full of effects pedal goodness.
posted by xedrik at 10:44 PM on January 22, 2020