synth

139 Articles

Disposable Vape Becomes Breath-Activated Synth

March 24, 2026 by 11 Comments

Makers and hardware hackers have been collecting disposable vapes for some time now, usually to salvage their batteries or the unique displays many models now come with. But you can also repurpose them for other ends, such as playing music. [Becky Stern]’s vape synth is a perfect example of this.

The build started with an ElfBars BC5000 vape. [Becky] notes there may be similar models under different names out there that would work just as well. The vape is effectively gutted for parts, with the LiPo cell, USB charging board, and the low-pressure sensor the main things that remain. These parts are combined with a drop-in 555 synthesizer circuit complete with speaker, which has its pitch controlled by a series of six photoresistors. When the low pressure sensor is triggered by inhalation, the 555 circuit is triggered, and operates at a pitch depending on the resistance of the photoresistor stack.

The output of the vape synth is kind of shrill, and frankly a little bit annoying — which is somehow rather fitting for what it is. If you want to make a better-sounding synth at home, we’ve featured such projects, you’re just unlikely to fit them entirely within the housing of a disposable vape.

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Analog Siren For Psychedelic Soundscapes

March 21, 2026 by 4 Comments

For better or worse, there are a few instruments that have been pigeonholed into specific genres of popular music. For example, banjos are often heard in bluegrass or folk, harmonicas in blues, and a sick horn section will take many of us immediately to third wave ska. Similarly, there are certain styles of synthesizers tied to various genres and if you’re a fan a certain sub-genre of reggae you’ll be familiar with the dub siren. This unique analog synth has a few tricks up its sleeve and [Jakub] shows us how he built his.

He’s calling this build the Sirenotron, and its based on the venerable 555 timer It also features an LFO built on an LM358, with triangle and square wave modes, plus an additional “acid mode” for the square wave which adds a single capacitor to the circuit but makes a big difference in the sound. Like any siren synth, there are potentiometers to control pitch and the pulse rate of the siren as well and another switch controls whether it is outputting sound or not. He’s also included the ability to control it with a foot pedal so he can use it while playing the bass guitar during live shows.

[Jakub] has gone through several prototypes before getting to this stage, and not only uses it when playing dub but also creates psychedelic soundscapes in a side project of his where it also fits right in. He’s also made the schematics available for anyone who wants to reproduce it or build on his design.

We’re always interested in a unique synthesizer build around here, and some of our favorites include this synth built from Sega Genesis parts and this one controlled more like a woodwind instrument.

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Upgrading The E-mu Audity 20 Years After Factory Support Ended

February 8, 2026 by 18 Comments

If you purchased an E-mu Audity 2000 ROMpler back in 1998, you almost certainly got a rig with the 1.00 firmware. It was fine, if a little limited, particularly where upgradability was concerned. E-mu would later offer firmware upgrades over MIDI with the 2.00 firmware, but to get the 2.00 firmware, you needed to ship the box back to E-mu. Or you did… until now.

Realizing that E-mu is long gone and they weren’t going to handle any further firmware upgrades, [Ray Bellis] set about finding another way to help aggrieved operators with gear stuck on v1.00. [Ray] had managed to lay hands on a Audity 2000 service manual as well as the official 2.00 upgrade kit in an estate sale, and set about reverse engineering it to help the community. It turned out that upgrading from 1.00 to 2.00 required the use of a special boot ROM and a flash device containing the upgraded firmware image. Booting from the special ROM required the use of a jumper, and when engaged, the ROM would copy the updated image to the device itself.

[Ray] didn’t want to duplicate the standard upgrade device, as that seemed a little difficult what with parts availability in 2026. Instead, he crafted his own ROM that, with compression, contained the necessary firmware upgrade image and could all be stuffed inside a single 512 KB chip. All you need to do is flash the custom upgrade ROM to an AM29F040B PLCC32 NOR flash chip, pop it in the empty PLCC32 socket on the mainboard, and away you go. This will get you a machine upgraded to the final v2.01 firmware delivered by E-mu before its demise.

It’s a finicky bit of work, but it’s a great way to get new functionality out of an old Audity 2000. We’ve featured similar work before regarding aging Yamaha synths, too. If you’ve got your own backdoor methods for giving older music hardware a new lease on life, don’t hesitate to notify the tipsline.

Building A Simple Ribbon Synth

November 29, 2025 by 1 Comment

The usual input device for playing a synthesizer is the good old piano keyboard. However, you don’t have to stick to such pedestrian interfaces when making music. [Daisy] has a fun build that shows us how to put together a ribbon synth that makes wonderful little noises.

Naturally, the heart of the build is a ribbon potentiometer (also known as soft pots). It’s essentially a touch sensitive strip that changes in resistance depending on where you touch it. You can slide your finger up and down to vary the output continuously; in musical contexts, they can behave rather like a fretless instrument. [Daisy] employs one of these potentiometers in such a role by hooking it up to a Daisy Seed microcontroller board, which reads it with an analog-to-digital converter (ADC). The resistance values are used to vary the pitch of a dual-saw synthesizer programmed in the plugdata framework.

We’ve featured some other great ribbon synths over the years, too, like this tribute to the Eowave Persephone. They’re not the ideal choice for those that prefer their notes on pitch, but they’re beautifully fun to play with when you’re getting a little more experimental.

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A small, colorful synth built for a 3-year-old. It has five pots, four sliders, and a tiny screen.

Baby’s First Synth Was Daddy’s First Project

November 22, 2025 by 7 Comments

We absolutely adore inspired labor-of-love tales such as this one. [Alastair] wanted to build a synth for his daughter’s third birthday in spite of having no prior hardware knowledge. It became the perfect excuse to learn about CAD, microcontrollers, PCB design, and of course, 3D printing.

So, why a synth for a toddler? Aside from plain old ‘why not?’, the story goes that she received a Montessori busy-type board which she seemed to enjoy, and it reminded [Alastair] of the control surface of a synth. He wondered how hard it could be to build something similar that made sound and didn’t require constant button presses.

[Alastair] began his journey by dusting off a 15-year-old Arduino Inventors Kit. The initial goal was to get potentiometer readings and map them to 12 discrete values, and then emit MIDI messages. This was easy enough, and it was time to move to a synth module and an Elegoo Nano.

The full adventure is definitely worth the read. Be sure to check out the pink version in action after the break. You really don’t wanna miss the lil’ panda bear. Trust us.

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A Casio Toy Synth Is Ready To ROCK!

October 11, 2025 by 6 Comments

There is likely to be more than one of you who has eyed up a child’s toy synthesizer in a second hand store, and considered making something more impressive with it. In many cases these instruments are underwhelming, having a very small subset of functions based into their black-epoxy-blob microcontrollers.

[Make Something] found a Casio toy synth that has a few more functions than the average model, and with the addition of some extra effects electronics and a beautifully made case, turned it into an altogether more interesting instrument.

Most of the video has an element of workshop porn about it, as he makes a very nice Moog-style console case for it, a task made easier by an impressive array of CNC tools. The electronics are slightly more interesting, being a selection of cheap guitar pedals gutted and combined with a cheap tube preamp board. The result is a machine capable of some far more interesting sounds

We think many Hackaday readers would be able to repeat these functions from scratch without the pedals, and while the case is a thing of beauty it’s likely a decent job could be done with a little less finesse on more commonplace tools. Perhaps it’s worth giving those toy synths a second look, because they really can be had for pennies if you look hard enough. Perhaps it’s an easier option than a previous toy musical upgrade.

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Round And Round With A Tape Delay Synth

September 11, 2025 by 7 Comments

Over the years we’ve been entertained by an array of musical projects from [Look Mum No Computer], and his latest is no exception. It’s a tape delay, loop generator, and synth all in one. Confused? That’s what you get if you position a load of tape heads around a rotating disk with magnetic tape on its perimeter.

Taking a circular piece of inch-thick Perspex, he wraps a length of one inch tape round its perimeter. This is placed as though it were a turntable on a stepper motor with variable speed, and the tape heads are positioned around its edge. Each read head feeds its own preamp which in turn drives a mixer array, and there’s also a record head and an erase head. If you’ve ever played with tape loops you’ll immediately understand the potential for feedback and sequence generation to make interesting sounds. There’s a lot of nuance to the build, in designing the mount for the motor to stop the enclosure flexing, in using a gearbox for increased torque, and in balancing the disk.

The result is as much an effect as it is an instrument in its own right, particularly in its prototype phase when the read head was movable. We’re treated to a demo/performance, and we look forward to perhaps seeing this in person at some point. There’s a future video promised in which a fix should come for a click caused by the erase circuitry, and he’ll make a more compact enclosure for it. Continue reading “Round And Round With A Tape Delay Synth” →