The real long-term future of computing consists of figuring out how to make the best possible use we can out of the literal millions of devices which already exist.

(Solderpunk, 2020, Cited in de Valk, 2022) (de Valk, 2024)

Beware! If you’ve picked up this publication expecting to learn how to make a flawless, DAW-less, in tune and always working polysynth, think again. However, if you, like me, are interested in making screamy, dreamy, sound devices using components you can find in the wild, you’ve come to the right place.

When I first read about salvage computing, I got very excited. Being part of the DIY Sound community, as a sound practitioner and hardware hacker, I’ve developed a growing discomfort with some aspects of the practice. Within the DIY Sound community, DIWO workshops are a common way of sharing knowledge (Richards, 2017), covering a wide range of topics, from the construction to bending and hacking and live coding. Over the past few years, I’ve hosted workshops around circuit bending¹ and LOFI sound devices in and around Rotterdam. These workshops are meant as an accessible way to get people tinkering with electronics, through something infinitely playful: making instruments².

In an ecosystem where a printer is only printing with a costly subscription ³, disruptive products become obsolete within a year⁴, fixing your own flat tires is outsourced ⁵ and some smartphones literally have to be frozen to be able to replace the battery ⁶, it’s clear we’re no longer in charge of our own devices. Warranty-void stickers and lengthy terms and conditions scare us into compliance.

First time soldering workshops can be very empowering in taking back this autonomy by making (or breaking) a circuit together⁷. They are a shared attempt to uncover some of the black boxes in our own products (Hertz and Parikka, 2012). However, the toys and materials used in the workshops are single-use ⁸ and, with ease, thrown out afterward. The carelessness notion creeps in that waste has no value, and is easily replaceable, and broke my heart a bit, one workshop at a time.

This is where the field guide comes into play: Can we shift the practice of playful tinkering to acknowledge, rather than ignore, the waste streams they are part of? Limiting ourselves to only use salvaged components and discovering; is it possible to live off (create with) electronic components salvaged in the wild? And what would such a practice entail?

Because salvage is not just about reusing materials; but about confronting the systems that create the waste in the first place. Not only the obsolete media but also the by-product of the entire production lifecycle of an electronic product; From the mining of minerals that make up the hardware to the inevitable disposal site (Gabrys, 2012). Since the rate at which waste is collected and recycled isn’t growing at the same pace as our collective buying and production, the landfills will continue to grow. Parikka even goes as far to say as that recycling is ultimately “waste-trade”, where our abandoned devices are shipped across the ocean (Parikka, 2012).

Beyond the kit

The preference for buying new is noticeable in the DIY synth community as well. When publishing a project, it’s common to share a pre-filled webshop cart along with the schematics or even sell it as a pre-compiled kit⁹. To me, this goes against the ethos of DIY that resonates with me the most: making do with what you have, with a focus on doing, and not the outcome (Hertz, 2023). Instead, a whole market is created for Lego-like kits. These kits gloss over the challenges and difficulties of creating sound devices, preventing the development of much-needed problem-solving skills, and not actually discovering anything new (Brown, Ferguson and Bennett, 2019).

Instead, what you will learn to build using this guide is a starting point. Small electronic circuits that produce sound on their own, but can also be duplicated, manipulated, and modulated ¹⁰, while diving into the questions around the practice of salvaging. The guide is tested, tinkered, and tweaked during (un)repair cafe evenings at the Klankschool¹¹. In these hangouts we modify, hack and repair devices together.

The guide is split up into the different stages of salvaging:

1. Gathering hardware

We trace where to find discarded electronics and how industry practices shape what ends up in the trash.

2. Dismantling devices

Opening up devices to uncover design strategies that prevent access

3. Components to salvage

Identifying and extracting useful components—motors, sensors, chips, while diving deeper in their material.

4. Recipes for making

Methods for building sound devices.

5. Taking inventory

Time to clean the workbench and reflect

Happy scavenging!

When salvaging for parts, we are looking for abandoned hardware. Hardware that is still fine on the inside but no longer considered as functional by its previous owners¹. These devices can be a literal goldmine of working parts that could be repurposed, as they probably still function, it’s the stylistic obsolescence that is the problem.

Remy & Huang argue that the core goals of ICT are simply researching new technologies and selling more products (Remy and Huang, 2015). To achieve the latter, manufacturers have embraced structured obsolescence: the idea that a product has a limited lifespan and ought to be consumed and upgraded within a few years (Sterne, 2007). This strategy is embedded in the manufacturing, marketing and even the naming of products ². It’s been embedded in consumer culture since the late 19th century, originally invented as a solution for overproduction (Hertz and Parikka, 2012). As a result, many devices have since been upgraded, replaced, devalued, and thrown out, before ever reaching their full potential (Parks, 2007). It is exactly these machines we are looking for. So, where to find them?

I’ve identified 3 strategies for gathering electronic hardware.

1. Institutional discards

Offices, schools, museums, or other companies often replace their hardware every 5 years, whether it’s broken or not, due to tax regulations³. If electronics aren’t central to their operations, their leftovers often gather dust. Keep your ears open, utilize your network, these forgotten machines could be your best source.

2. Browsing the streets

I feel like good waste “comes to you”. Keep your eyes open, look around. Actively going on waste walks has not paid off ⁴. Their chances depend heavily on local waste policies ⁵ and activities⁶.

3. Donations from friends & family

As you enthusiastically keep your friends & family in the loop about your salvaging endeavors, you’ll notice the phenomenon of donations. Since a sizeable portion of our replaced computing devices still reside in our storage units, waiting to be of any value, most would be happy to find such a good destination as you (Gabrys, 2011).

Infiltrating the waste stream

My attempts to create a consistent waste-income through more official routes have not been successful. These established waste streams, where trash is being collected, organized, and processed in multiple facilities, are difficult to trace. Rotterdam collects e-waste via official centers and drop-off bins, usually placed inside supermarkets. The emphasis is on bringing waste in. What happens after is vague and leans heavily on a promise of a circular economy⁷.

Consumer devices can be returned to the manufacturer through recycling programs. Here too, it’s unclear what exactly happens with the returned devices, and the program is always part of a customer journey ⁸. This relieves the consumer of the disposal responsibility but keeps the cycle of buying new unaltered.

Trying to engage with these streams differently, by salvaging, not just discarding, is nearly impossible. Access is tightly controlled. Waste is only moved when it can be translated into monetary value, and even then, only in bulk. Taking from recycling centers is prohibited; solo salvaging has no place in this transaction⁹.

Pick your battles

When inspecting a device for salvage possibilities, I try to imagine what the inside of the device looks like. What kind of components might I find? Are there any motors or moving parts? What kind of material is the device made of? What time period does it come from? Which companies manufactured the device and its parts? Is there an audio signal on the inside? Do I see any use for it now?

If I don’t expect much, I’ll leave it for the next person to salvage.

Once you’ve found a piece of hardware, it’s time to start dismantling the device. Let’s set up a workspace where you can easily move your device around and keep track of small parts. To take the device apart, we will need some tools. Which specifically differ a bit per device, but this is what I have in my own toolkit:

To open devices

• A set of screwdrivers with various bits and sizes ¹
• Plastic spudger or pick — Used to pry open seams without damaging the casing
• Saw or utility knife - cut through plastic cases or stubborn sections
• Flat pliers - for heavy duty pulling
• Drill - to drill through stuck and damaged screws
• Tweezers

For salvaging & making

• Multimeter — Tests components for continuity, resistance, or voltage
• Soldering iron & solder
• Desoldering pump
• Solder wick
• Flux
• Alligator clips - quickly make connections without soldering
• Thin copper wire²
• Battery powered speakers for listening + audio cable
• 9V batteries

Opening up

It’s not always clear where to start. Grabbing a heavy duty tool immediately could result in permanent damage. It is better to start more carefully. In some cases, product manufacturers provide service manuals³. But in most cases, we’re left to figure it out ourselves. Fortunately, online communities like IFixIt create their own teardown guides, that can sometimes give us a head start.

Let’s take a look at the device. Can you spot any screws? They might be hidden behind warranty stickers⁴ or tucked away in obscure corners. I find it helpful to follow the seams of the casing. Especially with plastic enclosures, it’s not just screws—look for small tabs or glue holding things together.

If you manage to create a small slit gap in a seam, insert a thin plastic pic and carefully push it along the seam. There might be small tabs holding the casing together. If the manufacturer really didn’t want you to get in there, they’ve glued it all up, and it is impossible to get in the device without causing permanent damage⁵.

Disassembly is really about patience and finding those small gaps in the enclosures, pulling and pushing until you’ve dismantled the entire device. Did you manage? Amazing! You’re now staring at the messy, material reality of your device⁶.

Uncovering black boxes

Through design choices like hiding screws, heat stakes⁷, strong adhesive, and using various screw sizes, it becomes clear: the manufacturer really does not want you in there. These are black boxes by design, destined to become obsolete, as replacement parts are not available, and critical components are not interchangeable. The only option is to buy an entirely new product again.

The act of black boxing are an attempt to keep us unconsciously incompetent, and increases the distance between the consumer and the materiality of the device. The modern laptop is silent, not giving any indication of whatever is happening on the inside, or its material origins. It is only when something breaks, that their materiality becomes a reality again (Hertz and Parikka, 2012) (Emerson, 2021).

It is by opening the devices, however, that we can rediscover materiality. Then it becomes clear that what may appear so robust, seamless, and futuristic on the outside is fragile, breakable and almost futile on the inside. With the Multimeter we can track the traces from the speaker to the microchip to the microphone. Or is there something else in between?

Discoveries at the (un)repair cafe

Once you’ve broken your device down into its individual puzzle pieces, we can zoom in on them more closely. Is there anything that immediately sparks your interest? Did you already uncover unexpected materials? Chances are you uncovered one or more Printed Circuit Boards (PCBs), and—very generally speaking—some kind of input and output components, all connected by several types of wire¹. For example, inside a digital picture frame I found a power input, a battery, a screen, speakers, a two-sided PCB, and an antenna.

PCBs are populated with either “through hole” (THT) or “surface mount” (SMD) components. SMD components are very small and soldered directly onto the board’s surface. Their size makes labels hard to read, and they’re designed for automated assembly, making them impractical for salvage². That’s why I rarely salvage from computer-type devices. These usually contain nothing but SMD components and lack interesting interactions or mechanical parts.

Desoldering

Desoldering components is generally more difficult than soldering and requires patience and practice. Ironically, desoldering guns are much more expensive than soldering irons, so here’s how I do it, without one.

In a well-ventilated³ room, heat up the blob of solder that connects the component to the PCB using a soldering iron. After a couple of seconds, you’ll notice the solder becomes liquid⁴.

Then, using tweezers or a plier, I carefully pull the leg out from the backside of the board, and then do the same for the other legs. This process can take somewhere between 10 seconds and 10 minutes and can be both frustrating and meditative.

Common components

In the next few pages, I’ll briefly address some of the more common components. If you want to know more about what each component specifically does, I recommend Getting started in electronics (Mims, 1983).

Many components, like transistors and chips, have datasheets available online. You can usually find them by entering the part number, often printed directly on the component⁵, into a search engine. While datasheets can be overwhelming and full of technical jargon, they typically show a pinout, explaining what each leg does, and a description of the component’s behavior.

In the next chapter, we’ll get into making with the salvaged components. The recipes need some specific components, which are highlighted below. It’s always wise to have some extra! Components might break, speaking from experience, having to stop because you’ve run out of working components, is very discouraging.

Overview of common components

Name	Category	Description	Found in	Symbol
555 Timer	Chip	A small chip that generates pulses	Timers, LED dimmers
Capacitor	Capacitor	Store a voltage	Everywhere!
Coil	Passive	These funky components can create sounds on their own	Transformers, relays, wireless charging
Crystal Oscillator	Passive	Generates a frequency that is often used as a clock	Devices that have processors
Diode	Passive	Forces current to flow in one direction	Everywhere!
Displays	Output	Display information	Monitors, calculators, embedded systems
LED	Output	Emit a small light	Everywhere!
Logic chips	Chip	Create logic and switches	Computers, microcontrollers, control circuits
MOSFET	Chip	Not sure yet	Power supplies, motor control
Magnet	Misc	Electromagnetic applications, motors	Speakers, hard drives
Microcontroller	Chip	Programmable chip, for example the ATmega328	Embedded systems, Arduino, automation
Microphone	Input	Record sound	Phones, vapes
Motor	Output	Spins when a power is applied	Printers, blenders, vacuums
NPN Transistor	Transistor	Amplification/switching	Everywhere!
Op-Amp	Chip	Amplifying signals	Audio circuits, sensors, control systems
PNP Transistor	Transistor	Amplification/switching	Everywhere!
Piezo disc	Ouput/Input	Records or creates vibrations	Buzzers, sensors
Potentiometer	Resistor	Limiting voltage through a knob	Volume knobs, light dimmers
Relay	Switch	Switches power	Household appliances
Resistor	Resistor	Limiting voltage	Everywhere!
Speaker	Ouput	Outputs sound	Toys, (portable) radios
Switches & buttons	Input	Interact with the device	Light switches, keyboards
Thermistor	Resistor	Limiting voltage dependent on temperature	Not sure yet
Trimpots	Resistor	Limit voltage through a small knob adjustable with a screwdriver	Audio circuits, calibration devices
Voltage regulators	Chip	Not sure yet	Power supplies, embedded systems

Hopefully, you’ve salvaged a variety of components by now, and we can start building sound with them. In this chapter you’ll find a bunch of recipes; the starting points for sound devices. These modular recipes can be used standalone or connected together into a bigger system. This modularity makes problem-solving slightly easier¹, and you can pick and choose your modules based on your salvaged inventory.

Every recipe contains a paper circuit² to print. These circuits are the blueprint of your device, between a schematic and an industrial PCB. The biggest advantage of using paper, apart from being able to solder the connections of your components right on top of the circuit, is that it is flexible. You can take notes, draw lines, and adjust the schematic as you go.

Assembling the circuit

1. Cut out the circuit and fold it in half, creating a two-sided print ³.
2. Gather the components listed in the “Bill of Materials” (BOM).
3. Populate the first components by pinning the legs through the paper in their designated areas. Keep an eye on the orientation⁴. Start small (resistors) then move to larger parts.
4. Create the connections according to the circuit by soldering the legs together using (copper) wire.
5. Repeat until all components are in place!
6. Test & triple-check all connections ⁵.

There is no need to understand every single component on each recipe ⁶ but try to follow the connections on the circuit. Which road is the audio signal taking? This will help you a lot with troubleshooting.

!Safety notes!

• Audio can be surprisingly loud. Use small speakers (never headphones! ⁷) you wouldn’t miss if they break and keep your hand on the volume dial when plugging in your sound device for the first time.
• Use batteries. Plugging into a wall (120V) can be incredibly dangerous. Always unplug the power from the circuit when making changes, to prevent shorts.
• Watch that smell. “Magic smoke” has a certain smell. Unplug immediately when something smells/smokes!
• Two know more than one. If you’re not sure, invite a friend and I’m sure you’ll figure it out together.

Finding recipes

The DIY synth community is not shy in sharing their schematics. There are fantastic resources online, such as the Experimentalists Anonymous DIY Archives the wiki, Music from Outer Space and Handmade Electronic Music (Collins, 2009). However, finding resources using salvaged components can be tricky, as our requirements are a bit different. Most schematics either contain 20+ components or require (specific) chips, which have proven to be difficult to find. This limitation has been interesting, as it forces me to experiment with smaller schematics. Turning the oscillators into self-modulating instruments, by attaching them together using alligator clips, actually helped me to learn more about electronics & sound than any pre-made kit could ever do.

After all the dismantling, salvaging, desoldering, and re-making, it’s time to take inventory. For me, this is the moment to sit in the middle of a workshop, surrounded by the carcasses of printers, cassette recorders, and radios, and deal with the remainders. Can we shift the practice of playful tinkering to also account for the waste streams it engages with?

In the DIY synth community, tinkering often happens collaboratively, through workshops where participants solder prefabricated kits, as an accessible entry point into electronics. When I started the field guide, I imagined creating a similar format, but using only salvaged components. Logistically, that turned out to be much harder than expected:

Waste streams are difficult to tap into

The circular economy, often marketed as a fix for the mountains of e-waste, is structured to keep the consumer lifecycle of buying intact. There is no method in place for taking waste, meaning we must revert to using what comes on our path or is donated. Which is a lot, but not consistent.

Salvaging the right components

Most synths built in workshops rely on chips like the 555 timers and op-amps. These chips simplify builds, lower the total amount of components needed, increasing the chances of a participant completing the circuit. In the past few months, I haven’t salvaged a single 555 timer, and only a handful of op-amps. That is not nearly enough to provide a group of participants with components.

But maybe these limitations can also be an opportunity. If we let go of the expectation that everyone would walk out with a polished synthesizer, similar to those that can be bought in shops, new possibilities open up. The constraints of using e-waste as material can help us to think differently—to engage with different contexts or reimagine how existing technologies might be repurposed. Instead of following a set in stone schematic, the recipes are a starting point, which everyone can execute differently.

Fennis urges us to rethink waste, not just as a pile of discarded phones, but as the material it was before, including the toxic, environmentally catastrophic legacy. Through reverse engineering and hacking, they explore the material and learn what the technologies can do other than what it was designed for(Fennis, 2022). In other words, by dismantling a wired electronic razor, that was deemed obsolete and replaced for a battery powered razor, we can remove the abstraction layer and see that it is actually a blade, a power supply, and a motor, which in turn can become an instrument. In this way, we can see the end-of-life of a device, where the consumer is done consuming, as a moment of celebration, and give it an afterlife (Mansoux et al., 2023)!

It is this kind of tinkering that I think will make us more resilient against the ongoing attempts by major companies and manufacturers to keep us locked out of our devices (Lu and Lopes, 2024). For me, that means not just rethinking waste but also questioning the workshop format itself—and whether I want to keep using the format with it. And the truth is, I don’t think so. I see much more to explore in collaborative spaces such as the (un)repair cafe. This means, this is not the end of the field guide! It’s the beginning. There are many more alligator clips to connect.