Audio Effects Applied To Text

April 11, 2025 by Al Williams 3 Comments

If you are a visual thinker, you might enjoy [AIHVHIA’s] recent video, which shows the effect of applying audio processing to text displayed on an oscilloscope. The video is below.

Of course, this presupposes you have some way to display text on an oscilloscope. Audio driving the X and Y channels of the scope does all the work. We aren’t sure exactly how he’s doing that, but we suspect it is something like Osci-Render.

Does this have any value other than art? It’s hard to say. Perhaps the effect of panning audio on text might give you some insight into your next audio project. Incidentally, panning certainly did what you would expect it to do, as did the pass filters. But some of the effects were a bit surprising. We still want to figure out just what’s happening with the wave folder.

If text isn’t enough for you, try video. Filtering that would probably be pretty entertaining, too. If you want to try your own experiments, we bet you could do it all — wave generation and filtering — in GNU Radio.

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A Tiny Tape Synth

April 7, 2025 by Jenny List 12 Comments

Afficionados of vintage electric organs will know about the Melotron, an instrument from the 1960s that had pre-recorded sounds on a bank of tape loops. A real Melotron in working order will set you back a bit, but it’s possible to play with the idea using much more attainable hardware. [Decurus] has made a simple tape based synth using a cassette deck.

It uses a loop of cassette tape, and varies the pitch by changing the speed of the cassette motor. There’s an RP2040 and a motor controller, which can take a MIDI signal and use it to drive the motor. We’re sorry to see that there’s no recording of the result, but it’s described as a drone.

Part of this project is a 3D printed tape loop holder to fit a cassette mechanism. We won’t go as far as to call it a cassette in itself, instead it’s a sort of tape loop frame. We can see that it might be an interesting component for other tape loop experimenters, now that cassettes themselves are no longer ubiquitous. This certainly isn’t the first tape pitch synth we’ve seen.

3D Print (and Play!) The Super Mario Tune As A Fidget Toy

April 4, 2025 by Donald Papp 34 Comments

[kida] has a highly innovative set of 3D-printable, musical fidget toys that play classic video game tunes. Of course there’s the classic Super Mario ditty, but there’s loads more. How they work is pretty nifty, and makes great use of a 3D printer’s strengths.

To play the device one uses a finger to drag a tab (or striker) across the top, and as it does so it twangs vertical tines one-by-one. Each tine emits a particular note — defined by how tall the thicker part is — and plays a short tune as a result. Each one plays a preprogrammed melody, with the tempo and timing up to the user. Listen to them in action in the videos embedded just under the page break!

There are some really clever bits to the design. One is that the gadget is made in two halves, which effectively doubles the notes one can fit into the space. Another is that it’s designed so that holding it against something like a tabletop makes it louder because the surface acts like a sounding board. Finally, the design is easily modified so making new tunes is easy. [kida]’s original design has loads of non-videogame tunes (like the Jeopardy! waiting theme) as well as full instructions on making your very own versions.

Fidget toys are a niche all their own when it comes to 3D printed devices. The fidget knife has a satisfying snap action to it, and this printable linear toggle design is practically a fidget toy all on its own.

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70 DIY Synths On One Webpage

April 2, 2025 by Elliot Williams 14 Comments

If you want to dip your toes into the deep, deep water of synth DIY but don’t know where to start, [Atarity] has just the resource for you. He’s compiled a list of 70 wonderful DIY synth and noise-making projects and put them all in one place. And as connoisseurs of the bleepy-bloopy ourselves, we can vouch for his choices here.

The collection runs the gamut from [Ray Wilson]’s “Music From Outer Space” analog oddities, through faithful recreations like Adafruit’s XOXBOX, and on to more modern synths powered by simple microcontrollers or even entire embedded Linux devices. Alongside the links to the original projects, there is also an estimate of the difficulty level, and a handy demo video for every example we tried out.

Our only self-serving complaint is that it’s a little bit light on the Logic Noise / CMOS-abuse side of synth hacking, but there are tons of other non-traditional noisemakers, sound manglers, and a good dose of musically useful devices here. Pick one, and get to work!

Reviving A Maplin 4600 DIY Synthesizer From The 1970s

March 19, 2025 by Donald Papp 16 Comments

A piece of musical history is the Maplin 4600, a DIY electronic music synthesizer from the 1970s. The design was published in an Australian electronics magazine and sold as a DIY kit, and [LOOK MUM NO COMPUTER] got his hands on an original Maplin 4600 that he refurbishes and puts through its paces.

Inserting conductive pegs is how the operator connects different inputs and outputs.

The Maplin 4600 is a (mostly) analog device with a slightly intimidating-looking layout. It features multiple oscillators, mixers, envelope generators, filters, and a complex-looking patch bay on the right hand side that is reminiscent of a breadboard. By inserting conductive pins, one can make connections between various inputs and outputs.

Internally the different features and circuits are mostly unconnected from one another by default, so the patch board is how the instrument is “programmed” and the connections made can be quite complex. The 4600 is one of a few synthesizer designs by [Trevor Marshall], who has some additional details about on his website.

The video (embedded below) is a complete walk-through of the unit, including its history, quirks, and design features. If you’d like to skip directly to a hands-on demonstrating how it works, that begins around the 10:15 mark.

Synthesizers have a rich DIY history and it’s fascinating to see an in-depth look at this one. And hey, if you like your synths complex and intimidating, do yourself a favor and check out the Starship One.

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Repairing A Legendary Elka Synthex Analog Synthesizer

March 17, 2025 by Maya Posch 16 Comments

Handy diagnostic LEDs on the side of the tone generator boards. (Credit: Mend it Mark, YouTube)

Somehow, an Elka Synthex analog synthesizer made it onto [Mend it Mark]’s repair bench recently. It had a couple of dud buttons, and some keys produced the wrong tone. Remember, this is an analog synthesizer from the 1980s, so we’re talking basic 74LS chips and kin. Fortunately, Elka helped him with the complete repair manual, including schematics.

As usual, [Mark] starts by diagnosing the faults, using the schematics to mark the parts of the circuitry to focus on. Then, the synth’s bonnet is popped open to reveal its absolutely gobsmackingly delightful inner workings, with neatly modular PCBs attached to a central backplane. The entire unit is controlled by a 6502 MPU, with basic counter ICs handling tone generation, controlled by top panel settings.

The Elka Synthex is a polyphonic analog synthesizer produced from 1981 to 1985 and used by famous artists, including Jean-Michel Jarre. Due to its modular nature, [Mark] was quickly able to hunt down the few defective 74LS chips and replace them before testing the instrument by playing some synth tunes from Jean-Michel Jarre’s Oxygène album, as is proper with a 1980s synthesizer.

Looking for something simpler? Or, perhaps, you want something not quite that simple.

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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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