Playful ‘Space Dice’ Kit Shows Off Clever Design

March 28, 2026 by Donald Papp 4 Comments

[Tommy] at Oskitone has been making hardware synth kits for years, and his designs are always worth checking out. His newest offering Space Dice is an educational kit that is a combination vintage sci-fi space laser sound generator, and six-sided die roller. What’s more, as a kit it represents an effort to be genuinely educational, rather than just using it as a meaningless marketing term.

There are several elements we find pretty interesting in Space Dice. One is the fact that, like most of [Tommy]’s designs, there isn’t a microcontroller in sight. Synthesizers based mostly on CMOS logic chips have been a mainstay of DIY electronics for years, as have “electronic dice” circuits. This device mashes both together in an accessible way that uses a minimum of components.

There are only three chips inside: a CD4093 quad NAND with Schmitt-trigger inputs used as a relaxation oscillator, a CD4040 binary counter used as a prescaler, and a CD4017 decade counter responsible for spinning a signal around six LEDs while sound is generated, to represent an electronic die. Sound emerges from a speaker on the backside of the PCB, which we’re delighted to see is driven not by a separate amplifier chip, but by unused gates on the CD4093 acting as a simple but effective square wave booster.

In addition, [Tommy] puts effort into minimizing part count and complexity, ensuring that physical assembly does not depend on separate fasteners or adhesives. We also like the way he uses a lever assembly to make the big activation button — mounted squarely above the 9 V battery — interface with a button on the PCB that is physically off to the side. The result is an enclosure that is compact and tidy.

We recommend checking out [Tommy]’s concise writeup on the design details of Space Dice for some great design insights, and take a look at the assembly guide to see for yourself the attention paid to making the process an educational one. We love the concept of presenting an evolving schematic diagram, which changes and fills out as each assembly step is performed and tested.

Watch it in action in a demo video, embedded just below. Space Dice is available for purchase but if you prefer to roll your own, all the design files and documentation are available online from the project’s GitHub repository.

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SEGA Music To MODfile, (Semi)Automatically

March 27, 2026 by Tyler August 7 Comments

One thing SEGA’s MegaDrive/Genesis and the Commodore Amiga had in common was–aside from the Motorola 68000 processor– being known for excellent music in games. As [reassembler] continues his quest to de-assemble Sonic: The Hedgehog and re-assemble the code to run on Amiga, getting the music right is a key challenge. Rather than pull MIDI info or recreate the sound by ear, [reassembler] has written a program called Sonic2MOD to automatically take the assembly file music from the MegaDrive cartridge and turn it into an Amiga-style MODfile. He’s also made a video about it that you’ll find embedded below.

Of course how music gets made differs widly on the two systems. Amiga, famously has Paula, a custom ASIC designed for sampling, allowing you to play four eight-bit voices. The Sega, of course, has that glorious FM-synthesis chip from Yamaha synthesizing five channels of CD-quality sound and one channel of sample. It’s not as well known, but the Sega also has a bonus TI-compatible programmable sound chip (PSG) that can handle 3 square-wave tone channels and one noise channel. That’s ten total channels to the Amiga’s four, and CD-quality to 8-bit voices. Knowing all that, we were very curious how close to SEGA’s original music [reassembler] could get on the Amiga.

Before he could show us, [reassembler] needed to decode the SMPS files used on Sonic: The Hedgehog and many other MegaDrive games. Presumably he could have gotten a MIDI file online somewhere– there are oodles– but the goal was to reverse engineer Sonic from its cartridge for the Amiga, not download a lot of resources from the web. SMPS is a sort of programing language for sound, telling the Yamaha and PSG chips what to do.

In some ways, it’s not unlike the Amiga’s MOD format, which programmatically specifies how to play the sampled voices also stored in the file. Translating from one to another is a matter of reading the SMPS files, extracting the timing, volume, vibrato, et cetera, and translate that into a form the MOD file can use. Then [reassembler] needed to generate samples, which was an added hiccup because the Amiga can only handle 3 octaves vs the seven of the SEGA’s FM synthesizer. He’s able to solve this simply by generating multiple samples to span the Yamaha chip’s range, though, again, at only 8-bit fidelity. It doesn’t sound half bad.

What about the four-channel limit? That’s where a bit of artistry comes in; the automated tool produces MOD files with more voices, which MOD trackers can handle at increased computational load. Computational load you don’t need when trying to play a game. Scaling down the soundtrack to the Amiga’s limits is something [reassembler] already has practice with from his famous OutRun port, though, so we’re sure he’ll get it done.

All of this effort just to match the Mega Drive makes us appreciate what a capable little computer the Sega console was; why, you can even check your stocks with it! We’ve already featured [reassembler]’s Sonic port once before, but this music tool was interesting enough we couldn’t help ourselves coming back to it. The ability to play MOD files were pretty impressive when the Amiga came out, but nowadays all you need is a ten-cent microcontroller.

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Luthier Crafts Guitar From Cardboard

March 27, 2026 by Bryan Cockfield 18 Comments

The people at Signal Snowboards are well known not only for producing quality snowboards, but doing one-off builds out of unusual and perhaps questionable materials just to see what’s possible. From pennies to glass, if it can go on their press (and sometimes even if it can’t) they’ll build a snowboard out of it. At some point, they were challenged to build different types of boards from paper products which resulted in a few interesting final products, but this pushed them to see what else they could build from paper and are now here with an acoustic guitar fashioned almost entirely from cardboard.

For this build, the luthiers are modeling the cardboard guitar on a 50s-era archtop jazz guitar called a Benedetto. The parts can’t all just be CNC machined out of stacks of glued-up cardboard, though. Not only because of the forces involved in their construction, but because the parts are crucial to a guitar’s sound. The top and back are pressed using custom molds to get exactly the right shape needed for a working soundboard, and the sides have another set of molds. The neck, which has the added duty of supporting the tension of the strings, gets special attention here as well. Each piece is filled with resin before being pressed in a manner surprisingly similar to producing snowboards. From there, the parts go to the luthier in Detroit.

At this point all of the parts are treated similarly to how a wood guitar might be built. The parts are trimmed down on a table saw, glued together, and then finished with a router before getting some other finishing treatments. From there the bridge, tuning pegs, pickups, and strings are added before finally getting finished up. The result is impressive, and without looking closely or being told it’s made from cardboard, it’s not obvious that it was the featured material here.

Some of the snowboards that Signal produced during their Every Third Thursday series had similar results as well, and we actually featured a few of their more tech-oriented builds around a decade ago like their LED snowboard and another one which changes music based on how the snowboard is being ridden.

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Disposable Vape Becomes Breath-Activated Synth

March 24, 2026 by Lewin Day 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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Better Faux-Analog VU Meters

March 23, 2026 by Lewin Day 5 Comments

One of the coolest things about old hi-fi hardware is that it often came with flickety needles that danced with the audio level. You can still buy these if you want, or you can simulate the same look on a screen, as [mircemk] demonstrates.

It isn’t [mircemk]’s first rodeo in this regard. An earlier project involved creating simulated VU meters on round displays, but they were somewhat limited. Using the Adafruit GFX library on an ESP32 netted a working setup, but it was jerky and very jagged and digital-looking. It was more akin to a fake needle display running on an 8-bit computer than something that looked like a real vintage VU meter.

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Analog Siren For Psychedelic Soundscapes

March 21, 2026 by Bryan Cockfield 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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Simple MIDI Sample Player Runs On ESP32

March 19, 2026 by Lewin Day 4 Comments

[Jakub] is a musician, and found himself in need of a simple way to trigger samples via MIDI when on stage. So many commercial solutions exist, but most were overkill for the job or too messy and complicated to justify their use in a live environment. Thus, [Jakub] worked up Samplotron to do exactly the job needed with a minimum of fuss.

The project is based around the ESP32. It’s effectively a lightweight hardware sampler that can trigger sounds on command via MIDI. Sample data is loaded from an SD card, which also stores the device configuration. The Samplotron plays back mono 16-bit WAV files at 44,100 Hz, delivering audio via an ES8388 audio codec module connected via I2S. Two encoders are used to control the device, with a menu system presented via an SSD1309 OLED screen. Samples can be loaded and managed via this interface, and it allows tweaks to be made to volume levels and one-shot/loop playback as needed. MIDI input to the device is simply handled via the onboard UART functionality of the ESP32 itself.

It’s a neat little bit of music hardware that does exactly what [Jakub] needs and nothing more. We’ve featured similar builds before, like this neat RP2040 soundboard. If you’re building rad custom hardware for your own musical adventures, we’d love to know all about it.