ON A SATURDAY MORNING in November, a dozen people of all ages are assembled around a communal table with winter coats still on, carefully soldering wires to simple circuit boards. All around them, the building is crammed from floor to ceiling with vintage musical equipment, home-made synthesisers, and other outdated tech: organs, Eighties computers, a telephone exchange from the Twenties, a floppy disc from the Fifties, a battalion of Furby toys wired up to a keyboard and hundreds of other gadgets, some playfully modified, some lovingly restored.

This nerdy wonderland, known as ‘This Museum is (Not) Obsolete,’ is located in a nondescript building in the British seaside town of Ramsgate and was assembled by Look Mum No Computer, real name Sam Battle. He’s bustling around the space in a stripy jumper and skinny jeans, moving sheets of plywood and tinkering with broken machines. With blinking red lights, satisfyingly space-age knobs and switches, and steam-punk-looking vacuum tubes, there are machines in this building spanning a century of electronic music. It’s an ideal place to reflect on the history of PCBs, and the role they’ve played in shaping our world.

The building is always open on weekends for people to play with instruments, but today, Dutch synth builder and educator Veerle Pennock is teaching a group how to build their own DIY synths. We live in an age where our laptops and phones are so advanced, you’d need an engineering degree to open them up and understand what’s happening inside, but with these simple machines rooted in technology from another era, it’s possible to understand how little pieces of metal and electrical currents can be transformed into music.

“The first synthesisers came from organs really,” Battle says, gesturing towards a Compton Electronic Organ, a wardrobe-sized rack of wheels, belts, wires and tubes that looks, as one YouTube commenter says, something like a WWII code-breaking machine. It uses spinning metal discs with sine waves etched onto them that generate an electrostatic signal, amplified by valves, and would have been hooked up to keyboards and foot pedals to replace gigantic pipe organs in churches and cinemas almost a century ago.

“We’ve got a lot of technology here that’s pre-PCB,” says Mitch Johns, who organises workshops at the museum and helps restore the equipment. “If you look at the back of them, it’s a rat’s nest of point-to-point wiring: layers and layers of wires criss-crossing and components, all soldered together. It’s really time-consuming to manufacture, and it makes the product expensive and difficult to repair.”

Valves (also known as vacuum tubes) are made of thin glass with heated cathodes inside: not a recipe for resilience. It was when transistors replaced this technology as a way to control currents and amplify signals that electronic machines could become smaller and more reliable. An early Moog synthesiser from 1964 may look bulky to modern eyes — a shelving unit of equipment, covered in a tangle of cables — but compare it to a tube-based RCA synth from the late Fifties that occupies an entire wall, and it looks streamlined.

Because transistors were so much smaller than vacuum tubes, PCBs evolved as a way to precisely wire them together, with copper pathways mapped onto the surface of a board to connect components, which were inserted through holes in the board and soldered to copper pads on the other side. The first Moog synth had individual PCBs for its different modules, like oscillators and filters, and these were connected externally with patch cords. Beatles fans will know that George Harrison was an early adopter, getting a Moog synth shipped from the US to London in 1969, and bringing it to Abbey Road studios to use on the album of the same name.

The following year, the Mini-Moog was released: patch cords had been replaced by more complex internal PCBs, and the modules had been integrated into one slimmed-down machine. Now, synths were small enough to carry (just about) and cheap enough that professional musicians who weren’t members of the Beatles might be able to afford them; a little over $1,000 USD, rather than $10,000. They were quickly adopted by artists such as Sun Ra, Kraftwerk, and Prince to experiment with a completely new palette of electronic sounds.

Of course, that price (closer to 10 grand in today’s terms) was still unaffordable for most, and a build-it-yourself synth scene sprang up in the 1970s for electronics hobbyists who had more spare time than spare cash. Magazines like Elektor offered kits and guides for building semi-modular synths like the Transcendent 2000, one of the DIY synths in Battle’s collection, which you can hear on Joy Division’s debut album, released in1979.

NYC-based experimental composer Nicolas Collins, an early adopter of microcomputers for live performance, has been making electronic music for more than four decades and has seen the technology evolve. He couldn’t afford a synth as a teenager in the 70s – “they cost as much as a car” – but learned how to wire basic circuits in a process “like sewing, pulling the wires around.” He even had a friend who’d make his own rudimentary PCBs by drawing circuits on trans- parent paper, layering them over photosensitive boards with a copper layer, putting them out in the garden to expose them to the sun, and then dipping them in acid to etch the parts hit by light.

“That period was when the integrated circuit was introduced,” he says. “Previously, you built a device like an amplifier by taking these individual components and putting them together. But with the integrated circuit, you suddenly had this little bug with everything inside. It was like Lego, you could just click a few pieces together.” Over the course of the 70s, it became possible to stuff these chips with more and more components, until microprocessors became available in the 80s, “an entire computer on a chip.”

Meanwhile, PCBs became multilayered, making them smaller and more powerful, and surface-mount technology enabled this trend. “That was a massive paradigm shift,” Johns says. When components no longer needed ‘little legs’ to be pushed through holes in a board, miniaturisation could continue to ramp up, and robotic machines took over the precise job of mounting them on boards, speeding up mass production. Now electronic instruments could really become affordable, powerful and small enough to put in a backpack.

Battle has some interesting items in his collection from the 80s, including a Suzuki Omnichord, released in ‘81, with buttons that you can press to play preset tunes, and a plate that triggers sounds when touched, as the finger closes an analogue electrical circuit. Among the bands who used it are The Human League, Talking Heads and Devo. For the most part, though, this type of analogue circuit was becoming obsolete.

“The ‘80s is when digital came in, and analogue fell out of fashion,” Battle says. “The first commercially successful digital synth was the Yamaha DX7 in 1983. This is when computers were starting to become popular. In the 90s, people started controlling digital synths with computers, and then the 2000s were when they ditched the digital synths and just had computers doing everything.”

Of course, the minute it became possible to create powerful sounds on a laptop or phone app, a revival of interest in analogue technology began. Hobbyists like Battle and Johns became obsessed with restoring older tech. “It’s an active rebellion against throwaway culture to try to preserve things,” Johns says.

In the 21st century, this process of increasing computing power in ever-smaller packages has only accelerated. Now, as Sunil Chander, a Senior Electronic Design Engineer at InstaDeep, explains, it’s possible to “squash billions of transistors into a chip.” PCBs have evolved, too, being made of flexible materials such as polyimide (PI), or even totally reimagined. If you opened up an Apple Watch, you wouldn’t see a bunch of chips on a green board, but a single square encased in resin, made up of chips stacked on top of each other, connected by microscopic gold thread. While this is becoming the status quo for wearable devices, it means they are not repairable: if one microscopic component encased in resin fails, the whole thing becomes waste.

There are still plenty of uses for more traditional-looking PCBs, which are becoming more and more dense, presenting challenges that engineers must address when designing them. “It’s all very data hungry,” Chander says. “Everything has to be high speed, and this means the board starts to emit electromagnetic energy and heat. The trace itself starts vibrating.” Considerations like durability, repairability and heat resistance come into play.

Computer-aided PCB design has been important for decades, but new AI tools like DeepPCB can factor in complex requirements like these and speed up the workflow. “We’re trying to ease the engineer workload,” Chander says, “so they can be more creative in their tasks.” AI will likely play an increasingly important role in PCB design as complexity grows.

As the synth-building workshop wraps up, there’s a palpable sense of satisfaction among the attendees who have been patiently troubleshooting, making tweaks to their creations, and finally getting them to make space-age beeps and blasts of fuzz. In such a frictionless digital world, there’s something deeply appealing about tinkering with circuits at such a tactile level. At the same time, being able to look up troubleshooting tips online and take video clips of the event definitely enhances the process. For that, we can thank the digital innovation that got us from room-sized machines teeming with wires to palm-sized supercomputers in just a few decades.