Circuit Bending 101 (...and a little more)
Emily Elhaj
A blog post about pedal building on this website? Yesss. The creative minds behind your favorite EarthQuaker Devices started somewhere, and I wager a few were bending before building in EQD’s workshop in Akron, OH. When you snatch your new effects, bring them to rehearsal, and work through your favorite settings, is your next thought to look inside to see what makes them tick? This article is for you! Curious minds want to know, what is in this box of tone, flange, fuzz, and magic?
Our friend Wiki describes circuit bending as the “creative, chance-based customization of the circuits within electronic devices such as low-voltage, battery-powered guitar effects, children's toys, and digital synthesizers to create new musical or visual instruments and sound generators.”
With help from musicians, guitarists, and studio technicians, we’re here to get you even more excited about effects than you were already. Learn more about how your existing pedals work, tips to assembling pedal kits, and the boundless possibilities in modifying materials for unexpected results with musicians and engineers right here.
Ana da Silva, The Raincoats
Ana is a renaissance woman. She is a visual artist and musician with a curiosity for gadgets and electronics. I made the mistake of calling a hand-held device she owns a ‘game boy.’ Not my finest comedic moment but it was definitely meant tongue-in-cheek (forgive me!). Currently, she performs as half the collaborative duo with avant-electronic artist Phew (formerly of the Osaka band Aunt Sally). To be sure, both use a fair share of effects and modular devices on their album Island.
Ana introduces us to artist and circuit bender Olaf Larousse who initially piqued her curiosity about bending. She also shares a few personal stories, pieces of equipment, and her love of modular synths.
Photo by Olaf Larousse.
“I met Olaf Ladousse in Madrid when I did a solo performance at Ladyfest in 2005. He built amazing instruments out of great looking, mostly mundane pieces of electrical equipment, food tins, plastic containers, toys, etc. All had incredible charm and showed inventiveness.
After this meeting, I investigated circuit bending on the internet to see what would happen and what sounds I’d get from transforming some sound toys. I bought a soldering iron, some potentiometers, resistors, capacitors, and wire. I then went to charity shops to get second-hand children’s toys like small keyboards, plastic telephones, and anything that produces sound. I did circuit bend some of these toys mostly successfully, although I fried a ‘Speak and Spell,’ which made me sad as it had been very promising in its variety and the most expensive one I had bought!
I only used one publicly at the Donau Festival in 2009 where the Raincoats played. All the different bands involved in the event curated by Chicks on Speed played together on one of their songs “Girlmonster.” That’s when I produced the sounds of a modified green telephone.
I recorded a collaborative album with Japanese musician Phew called Island in 2018 where I used a modular synth and Phew used fixed architecture synthesisers. Modules are made of some similar components as the ones used in circuit bending, but much more complex. The [modular] system I use is Eurorack, invented by the German Dieter Doepfer which has been around for over 20 years.
I use modules from several manufacturers depending on what I want to use them for and what a specific module provides and costs. Some people build their own modules, but I’m more interested in making music than building modules. Also, you really have to know what you’re doing when you mess about with things that are connected to electricity as opposed to when using batteries like in circuit bending.
To start a modular synth, first you need a case with power supply. Then you put in oscillators (source of sound), filters (sound modifiers), LFOs, envelope generators (ADSR), sequencers, effects, mixers, and others depending on your needs. Each module has one or more functions and you connect them with patch leads. It’s very exciting when you connect two or more modules and you get a great sound. The variety of sounds is limitless and in my view can be very beautiful.
The EarthQuaker Devices Afterneath eurorack synthesizer module is coming in 2020.
At the moment there are almost 8,000 modules from manufacturers from all over the world. There’s a lot of choice and therefore sometimes it is difficult to decide what to get. They’re not cheap either. There aren’t many physical modular synth shops, so I order mostly online. There are loads of demonstrations on the internet, so you can have an idea of what each one does and sounds like. There’s also an informative and beautiful new book that explores modular synthesis: PATCH & TWEAK written by Kim Bjørn and Chris Meyer, and edited by Paul Nagle.”
Paul Sukeena, Guitarist for Spacin’, Steve Gunn, & Angel Olsen
Pedal board whisperer, guitarist, and unabashed Grateful Dead fan, Paul Sukeena lends his keen sense of tone and comprehensive knowledge of effects for a section on pedal kits and building. Paul has found his place in pedal craft by inventing out of necessity and imitating the well-worn tones of classic pedals.
EE: What are some of the basic supplies and tools for bending/building?
PS: First off, I’d recommend a soldering iron that has adjustable temperature control. You set it to a specific temperature and the iron will stay there throughout the build. You’ll also need rosin core solder. Using a smaller diameter helps with precision. As for smaller tools, a desoldering braid or pump is useful if you have to change something or made a mistake. A wire stripper, fine tipped wire cutters, and pliers are nice to have, too.
EE: Do you assemble your pedals? Where do you like to order from?
PS: I definitely don’t assemble all of them because some builds are far more complicated than others. Delays and flangers require a ton of parts and the builds are way out of my area of expertise. I tend to build simple circuits like fuzzes, boosts, and overdrives. Usually, I order pre-organized kits from General Guitar Gadgets. They come with everything you need: enclosures, PCB, switches, jacks, LED, and transistors/resistors. To piece together the parts for a build you simply find a schematic and it will, typically, include a list of all of the parts needed. You can order just about any part you’d need (barring vintage/weird specialty parts) from Mammoth Electronics.
EE: Describe a little about the Pi pedal and how yours differs from the original.
PS: The Pi pedal is a clone of an Electro-Harmonix Big Muff Pi. I built it on a whim because I wanted a specific version of the Big Muff, The Violet Rams Head (there are like 50 different versions of the Big Muff!) and I couldn’t afford the real thing. It turned out to be a super simple circuit and easy build. I think it took me like four hours total. I’ve literally used it with every project I’ve been a part of since I built it.
EE: Helpful tips for assembling pedal kits, modular synths, or circuit bending after your experience with each/any of these?
PS: Take your time and don’t be hasty. In the beginning, I was always excited to finish building so I could have a new toy. I’d make tons of mistakes and would always have sloppy solder joints. You have to take your time and put it down if you start making mistakes. Also, start out with a very simple circuit like a boost pedal. You can hone your soldering chops on something a little less precious or complicated.
EE: Why build your own?
PS: First of all, building your own pedals offers you the chance to cheaply gather a bunch of classic sounds for your tone quiver. You know you need as many flavors as you can get. Secondly, it gives you an intimate knowledge of the devices. With enough time and experience you can build more complicated circuits and even troubleshoot and diagnose issues when your pedals get sick.
EE: What boutique companies do you enjoy?
PS: I love Strymon, there’s also a builder out of Sydney called Bondi Effects that makes amazing sounding pedals, aaaand of course EarthQuaker Devices!
Matt Kingdon & Ian Taylor, Technical Engineers at Abbey Road Studios
Ian was kind enough to show me around one of the most revered studios (ever?), Abbey Road. He is a wizard when it comes to repairing machinery. He designs and builds gadgets for the studio when an ‘off the shelf’ option isn’t available. Ian and yours truly are collaborating on a pedal venture (adventure) currently. More about that soon!
Matt has been a technical engineer at Abbey Road for the last ten years. Prior to that he worked at Olympic Studios which is where he learned the trade. He keeps studio equipment in top shape by repairing and updating gear.
Emily Elhaj: What is an average day for you at the studio?
Ian Taylor: We have two main shifts. The day routine would be to go around the studios and check with an assistant or sound engineer to make sure they are set for the session. This could include lining up tape machines or ensuring an operator has access to the correct computer rig. Once the session is under way, we return to our projects unless we get called out to fix something.
Matt Kingdon: It’s one of those, ‘there is no average day’ answers I’m afraid. There are certain things which will need attention most days, for example, preparing the studios for the particular requirements of the upcoming session or simply repairing broken cables. Mainly, we will all have projects on the go to continue with. We keep updating the studios as technology and workflow changes. Also, when we get a chance, we get to build cool stuff for the studio.
EE: What projects are you working on?
IT: In this very moment, we’re fitting one of our mixing rooms to Dolby Atmos specifications by updating the infrastructure to easily handle the current and, hopefully, future requirements of film music.
MK: We are working on an installation of one of our studios as well as designing a parallel processing unit that an engineer has requested.
EE: Can you explain the difference between using classic circuits and circuit bending?
IT: Classic circuits would be topography you see across many circuits, like the Sallen-Key implementation of a Butterworth filter [a type of signal processing filter] or just standard functional combinations like amplifiers. Bending a circuit would be to modify or introduce something into an electronic circuit to make it do something it couldn't do before. From something as simple as adding a resistor knob for volume control to something like this bent ‘talking computer’ [by Freeform Delusion].
MK: Not really, apart from maybe the first iconic version of a circuit such as a tone bender for example but every circuit has been bent by someone. Builders have been nicking ideas from each other forever. That’s one of the cool things about it. Grab a bit from here, get your filtering from there or whatever. I have been meaning to replace the drive circuit in a Metal Zone for ages just so you can use the EQ with a fuzz.
EE: When you experiment with circuit bending, do you have a goal in mind for sounds or how the instrument will function?
IT: To be completely honest, I'm wary about circuit bending! Especially if you're going to be modifying elements that are essential to the circuit. My own personal ethos is, any modification you've done to a circuit should be reversible. However, yes, I often think it would be neat to have a control here or there or I wish it had another gain stage.
MK: To a certain extent, yes. Most of the stuff I’ve been playing with has been basic drive circuits so I would probably start with a basic clone circuit and see what it could do with. Maybe more saturation or change the filtering. Change the caps or resistors in that part of the circuit and see what happens. Happy accidents can happen.
EE: How did you learn to build pedals/circuit-bend?
IT: YouTube is an incredible source of knowledge. You'll find stuff there for the beginner all the way up to pretty advanced stuff. There are also plenty of pedal circuit libraries out there. Take time with circuit diagrams and Google every word if you must. Most pedals are built using little variation in building blocks and their combinations. The more you build them, the more you'll recognise them.
Personally, I started off with a couple of kits 'to get the feeling.' After that, I got a breadboard and some perfboard [a material for prototyping electronic circuits also called DOT PCB] and trial'd and error'd. For circuit bending, I'd start with something cheap. With bigger instruments, like synths, I'd be careful. Any circuit bending will probably affect the value of your instrument and your ability to maintain it.
MK: I was in a fortunate position that I knew my way around a circuit diagram due to the nature of my work, but being able to replace the correct broken component on a pricey piece of equipment and then building my own bit of gear are different disciplines. So, I started like a lot of builders and looked online for circuits I could put together.
The first pedal I built was on some variboard for a fuzz circuit I liked it because it had a cool name and a tone control and a mid shift control. I got that working after correcting a couple of mistakes and it sounded brilliant and thought “I don’t have to buy another pedal ever again.” It was more difficult trying to work out how to get it in a box that could take being stomped on. It is actually a four-in-one and I called it the Apocalypse Drive. The four circuits are based on an octave up, a fuzz, a boost, and a compressor. It only ended up like that because I had a box kicking about that was too big for one pedal! So something I didn’t mention before, necessity is the mother of invention. It is a splendid way of being forced to make things work.
For both the electronics and the mechanical build there were loads of videos, blogs, forums that are packed full of advice. Loads of people have all the same questions when learning to build so they have all been answered before, but the best thing I found is that no matter how badly you get the circuit build wrong at 9 volts it’s really difficult to blow stuff up (apart from electrolytic caps, they still pop if you put them in backwards). You can make loads of mistakes and can reuse the components.
EE: What are some of your tried and true supplies and tools?
IT: For DIY pedals, I’m a big fan of Weller soldering irons. Advice, don’t forget to get a holder for the iron . . . it gets hot and you'll want to put it down every now and again. I learned that the hard way, haha. [Other tools are] wire cutter, tweezers, and solder sucker. I also highly recommend practicing soldering wires and desoldering them beforehand.
MK: In terms of supplies, a multi pack of resistors and caps, polys and electrolytics, they are probably going to be the things you change to tweak the sound of whatever you are building. You’ll need a few reels of different colour wire and some variboard. The rest of it you get when you have a bill of materials drawn up for whatever you want to build. I tend to over order to the next price break for specific components which starts to build up my supplies.
In terms of tools. It does make your life so much easier with decent tools. Whatever you build or modify will be more robust if you use quality cutters and a good soldering iron. If you have a cheap low wattage iron you are more likely to have dry or just bad solder joints. A multimeter is necessary and, although a signal generator and oscilloscope are helpful, you can use a guitar and an amp for [testing] instead. Oh yes, a vice is also really handy.
EE: Favorite boutique companies or effects?
IT: Big fan of Analog Man, TouellSkouarn, and Strymon but the list goes on and on!
MK: I like ZVEX because they were the first pedal I can remember that seemed to come with this mystique of being hand-built and painted and that the controls didn’t do “what it said on the tin” so you had to work with it some. I also like Fulltone because every pedal of theirs I’ve tried sounded just right for what it is. There is a company called Brantone Electronics and the guy who builds the pedals used to build bits for the aerospace industry and his attention to detail is second to none. He has gone as far as painting red paint on all the solder joints in line with the specs of his previous work. Simply beautifully crafted pedals from top to bottom.
EE: Where do you like to order supplies from?
MK: For the most part, Mouser seem to have the best choice of components for pedal building but I use RS and Farnell as well. For the hard to find bits, eBay or a couple sites based in Korea are good for small quantities of very random stuff.
EE: Helpful tips for assembling pedal kits, modular synths, or circuit bending after your experience?
IT: Take your time, plan things, draw it out, mark the perfboard, and DON’T solder the IC [integrated circuit] to the board use a holder. Make sure you have a good source of light and fresh air when soldering. Lastly, if you can, test before you commit.
MK: Find a site with a forum. This can be very helpful when you come across a certain problem. There are almost certainly others who have had the same issues with their builds. Reading a blog regarding a specific build can be helpful to see what the common issues are with it. Once you have the pedal working, you can start changing things. Trying different resistor values is a good place to start. You can keep notes on what results different values reveal giving you a good feel of what each component does practically rather than just theoretically.
From New Orleans and currently based in Los Angeles, Emily Elhaj is a writer, photographer, and has performed and recorded with Angel Olsen, The Raincoats, Implodes, Sofia Bolt, Anna St. Louis, Vagabon, Hand Habits, and Jess Cornelius. She plays guitar and bass and is generously endorsed by Hofner, Fender, EarthQuaker Devices, & Original Fuzz. Emily runs the label Love Lion which began in 2010 and currently moderates an ongoing collection of conversations with creatives called the Love Lion Interview Series.
