Rebooting An 1973 Art Installation Running On A Nova

May 12, 2025 by Dave Rowntree 18 Comments

Electronics-based art installations are often fleeting and specific things that only a select few people who are in the right place or time get to experience before they are lost to the ravages of ‘progress.’ So it’s wonderful to find a dedicated son who has recreated his father’s 1973 art installation, showing it to the world in a miniature form. The network-iv-rebooted project is a recreation of an installation once housed within a departure lounge in terminal C of Seattle-Tacoma airport.

You can do a lot with a ‘pi and a fistful of Teensies!

The original unit comprises an array of 1024 GE R6A neon lamps, controlled from a Data General Nova 1210 minicomputer. A bank of three analog synthesizers also drove into no fewer than 32 resonators. An 8×8 array of input switches was the only user-facing input. The switches were mounted to a floor-standing pedestal facing the display.

For the re-creation, the neon lamps were replaced with 16×16 WS2811 LED modules, driven via a Teensy 4.0 using the OctoWS2811 library. The display Teensy is controlled from a Raspberry Pi 4, hooked up as a virtual serial device over USB. A second Teensy (you can’t have too many Teensies!) is responsible for scanning a miniature 8×8 push button array as well as running a simulation of the original sound synthesis setup. Audio is pushed out of the Teensy using a PT8211 I²S audio DAC, before driving a final audio power amp.

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Open Source Commercial Synthesisers You Will Love

April 23, 2025 by Jenny List 17 Comments

Drumboy and Synthgirl from Randomwaves are a a pair of compact electronic instruments, a drum machine and a synthesiser. They are commercial products which were launched on Kickstarter, and if you’re in the market for such a thing you can buy one for yourself. What’s made them of interest to us here at Hackaday though is not their musical capabilities though, instead it’s that they’ve honoured their commitment to release them as open source in the entirety.

So for your download, you get everything you need to build a pair of rather good 24-bit synthesisers based upon the STM32 family of microcontrollers. We’re guessing that few of you will build your own when it’s an easier job to just buy one from Randomwaves, and we’re guessing that this open-sourcing will lead to interesting new features and extensions from the community of owners.

It will be interesting to watch how this progresses, because of course with the files out there, now anyone can produce and market a clone. Will AliExpress now be full of knock-off Drumboys and Synthgirls? It’s a problem we’ve looked at in the past with respect to closed-source projects, and doubtless there will be enterprising electronics shops eyeing this one up. By our observation though it seems to be those projects with cheaper bills of materials which suffer the most from clones, so perhaps that higher-end choice of parts will work in their favour.

Either way we look forward to more open-source from Randomwaves in the future, and if you’d like to buy either instrument you can go to their website.

Thanks [Eilís] for the tip.

Probably The Simplest Sequencing Synth

March 15, 2025 by Jenny List 31 Comments

With inexpensive microntrollers capable of the most impressive feats of sound synthesis, it’s not so often we see projects that return to an earlier style of electronic music project. The 1-bit synth from [Electroagenda] takes us firmly into that territory, employing that most trusty of circuits, a 555.

It’s a time-honored circuit, a 555 provides a note clock that drives a 4017 that functions as a sequencer. This switches in a set of voltage dividers, which in turn control another 555 oscillator that produces the notes. It’s a fun toy straight from the 1970s, right down to the protoboard and hookup wire construction. There’s a demo video with some lovely beeps below, and we think most of you should have what it takes to make your own.

If you’re seeking more inspiration, may we introduce you to our Logic Noise series?

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Where Did Electronic Music Start?

September 7, 2023 by Jenny List 53 Comments

A culture in which it’s fair to say the community which Hackaday serves is steeped in, is electronic music. Within these pages you’ll find plenty of synthesisers, chiptune players, and other projects devoted to synthetic sound. Not everyone here is a musician of obsessive listener, but if Hackaday had a soundtrack album we’re guessing it would be electronic. Along the way, many of us have picked up an appreciation for the history of electronic music, whether it’s EDM from the 1990s, 8-bit SID chiptunes, or further back to figures such as Wendy Carlos, Gershon Kingsley, or Delia Derbyshire. But for all that, the origin of electronic music is frustratingly difficult to pin down. Is it characterised by the instruments alone, or does it have something more specific in the music itself? Here follows the result of a few months’ idle self-enlightenment as we try to get tot he bottom of it all.

Will The Real Electronic Music Please Stand Up?

Page from the Telharmonium patent, showing the tone wheels — If you own a synthesiser, the Telharmonium is its daddy.

Anyone reading around the subject soon discovers that there are several different facets to synthesised music which are collectively brought together under the same banner and which at times are all claimed individually to be the purest form of the art. Further to that it rapidly becomes obvious when studying the origins of the technology, that purely electronic and electromechanical music are also two sides of the same coin. Is music electronic when it uses an electronic instrument, when electronics are used to modify the sound of an acoustic instrument, when it is sequenced electronically often in a manner unplayable by a human, or when it uses sampled sounds? Is an electric guitar making electronic music when played through an effects pedal?

The history of electronic music as far as it seems from here, starts around the turn of the twentieth century, and though the work of many different engineers and musicians could be cited at its source there are three inventions which stand out. Thaddeus Cahill’s tone-wheel-based Telharmonium US patent was granted in 1897, the same year as that for Edwin S. Votey’s Pianola player piano, while the Russian Lev Termen’s Theremin was invented in 1919. In those three inventions we find the progenital ancestors of all synthesisers, sequencers, and purely electronic instruments. If it appears we’ve made a glaring omission by not mentioning inventions such as the phonograph, it’s because they were invented not to make music but to record it. Continue reading “Where Did Electronic Music Start?” →

An Open Hardware Eurorack Compatible Audio FPGA Front End

February 13, 2023 by Dave Rowntree 4 Comments

[Sebastian Holzapfel] has designed an audio frontend (eurorack-pmod) for FPGA-based audio applications, which is designed to fit into a standard Eurorack enclosure. The project, released under CERN Open-Hardware License V2, is designed in KiCAD using the AK4619VN four-channel audio codec by Asahi Kasei microdevices. (And guess what folks, there’s plenty of those in stock!) Continue reading “An Open Hardware Eurorack Compatible Audio FPGA Front End” →

How The Roland 808 Cowbell Worked

May 12, 2022 by Jenny List 9 Comments

Every generation has an instrument which defines its sound, and for those whose formative musical years lie in the 1980s, a very strong contender to the crown is the Roland TR-808 percussion synthesizer. Its sounds can be recognized across a slew of hits from that era and every decade since, and though the original instrument wasn’t a commercial success it remains accessible through sample packs, emulations, and clones. The 808 was an all-analogue device that didn’t use samples, thus [Mark Longstaff-Tyrrell] has been able to reproduce its distinctive cowbell sound with reference to some of the original circuitry.

It shouldn’t come as too much of a surprise to find that the circuit is refreshingly simple. The trigger pulse is converted into an envelope which controls a pair of oscillators. The mixed output passes through a bandpass filter to create the distinctive sound on the output which you can hear in the video below the break. The circuit is recreated on a breadboard with the only concession to modernity being a microcontroller taking the place of the Schmitt trigger oscillators in the original.

Altogether it provides a fascinating insight into the synthesis behind a classic sound, and gives us an increased appreciation for the design skills of those Roland engineers who created it. We’ve looked at the 808 before a few times, including an explanation of the famous faulty transistors which contributed to its sound.

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A Transistor-less Sound Synthesizer

October 24, 2020 by Jenny List 34 Comments

A synthesizer without transistors could almost be the basis of a trick question, surely without transistors it must be using a vacuum tube or similar. Not [Dr. Cockroach]’s synth though, instead of transistors it uses coupled pairs of LEDs and light-dependent resistors as its active components. Its oscillator circuit comes courtesy of [Patrick Flett], and uses a pair of LED/LDR combinations to alternately charge and discharge a capacitor. This feeds another LDR/LED pair that appears to act as a buffer to drive a bridge rectifier, with a final amplifier following it.

The result oscillates, though at frequencies in the low audio range with a cluster of harmonics thrown in. Its sound is best described as something akin to a small single-cylinder motorcycle engine at the lower frequencies, and is something we see could have all sorts of interesting possibilities.

This approach of using LDR-based active devices may be something of a dead end that could have had its day back in the 1930s, but it’s nevertheless an entertaining field to explore. It’s not the first time we’ve followed [Dr. Cockroach] at it, in the past we’ve seen the same technique applied to logic gates.

Have a listen to the synth in the video below the break. Continue reading “A Transistor-less Sound Synthesizer” →