While the days of audio cassette tapes are long over for almost everyone, magnetic tape still enjoys extensive use in some other realms such as large-scale data backup. Those that are still using it to store their tunes are a special subset of audio enthusiasts. [Frank] still has a working tape deck, and enthusiasm for classic non-vinyl sound. His homage to audio tape? Building a working cassette made (almost) entirely of wood.
The cassette is modeled on the formerly popular Maxell XL-II and the first versions of this build were modeled in paper. Once the precise dimensions of the enclosure were determined, [Frank] got to work building the final version from wood in a decidedly 2D process. He used a plotter to cut layers out of a wood veneer and glued them together one-by-one. The impressive part of this build is that the tape reel bearings are also made from wood, using a small piece as a race that holds the reels without too much friction.
Once everything was pieced together and glued up, [Frank] had a perfect working cassette tape made entirely from wood with the exception of the magnetic tape and a few critical plastic parts that handle the tape directly. The build is an impressive piece of woodworking, not unlike the solid wood arcade cabinet from a few days ago.
Ever heard of a handpan? If not, imagine a steel drum turned inside out, and in case that doesn’t help either, just think of a big metal pan you play music with by tapping your hands on its differently pitched tone fields. But as with pretty much any musical instrument, the people around you may not appreciate your enthusiasm to practice playing it at any time of the day, and being an acoustic instrument, it gets difficult to just plug in your headphones. Good news for the aspiring practitioners of Caribbean music though, as [Deepsoul77] created a MIDI version of this rather young and exotic instrument.
Using the foam salvaged from an old mattress as the core of the handpan, [Deepsoul77] cut a couple of plywood pads as tone fields that will be attached to the foam. Each plywood tone field will then have a piezo element mounted in between to pick up the hand tapping. Picking up the tapping itself and turning it into MIDI signals is then handled by an Alesis trigger interface, which is something you would usually find in electronic drums. From here on forward, it all becomes just a simple USB MIDI device, with all the perks that brings along — like headphone usage or changing MIDI instruments to make anything sound like a trumpet.
Anyone who has through the process of learning to play a musical instrument for the first time, or listening to someone attempting to do so will know that it can be a rather painful and frustrating experience. [Alessandro Perini] apparently couldn’t get enough of the sound of a first-time musician, so he created a robot to play the melodica badly for hours on end, as demonstrated in the video after the break.
The project is appropriately named “AI’ve just started to learn to play”, and attempts to copy every melody it hears in real-time. The robot consists of the cartridge carriage from an old printer, mounted on a wooden frame to hold the melodica. The original carriage used a DC motor with an encoder for accurate movement, but since position accuracy was not desirable, [Alessandro] ditched the encoder. Two small trolley wheels are mounted on the cartridge holder to push down on the melodica’s key. A bistable solenoid valve controls airflow to the melodica from an air compressor. The DC motor and solenoid valve is controlled by an Arduino via a pair of LM298 motor drivers.
A host computer running software written in Cycling ’74 MAX listens to the melody it’s trying to imitate, and send serial commands to the Arduino to move the carriage and open the solenoid to try and match the notes. Of course, it keeps hitting a series of wrong notes in the process. The Arduino code and build instructions have been published, but the main Max software is only described briefly. [Alessandro] demonstrated the robot at a local festival, where it played YouTube tutorial snippets and jammed with a local band for a full 24 hours. You have to respect that level of endurance.
It works like this: either shine some light on the photocells, cover them up, or find some middle ground between the two. No matter what you do, you’re going to get cool sounds out of this thing.
The photocells behave like potentiometers that are set up in a voltage divider. An Arduino UNO takes readings in from the photocells, does some MIDI math, and sends the serial data to a program called Hairless MIDI, which in turn sends it to Ableton live.
[knaylor1] is using a plugin called TAL Noisemaker on top of that to produce the dulcet acid house tones that you can hear in the video after the break.
Inspired by the creative genius of Martin Molin of Wintergatan fame, [iSax] set out to create a robotic MIDI-controlled trombone. It takes years for humans to develop the control and technique required to play the trombone well as the tone produced into the mouthpiece (embouchure) is a tricky combination of air pressure, lip tension, airflow, resonance in the mouth, and other sources of complex pressure.
[iSax] gives a thorough walkthrough of the machine, which is powered by two separate sources of air, one for the position of the slide and the other for producing sound. A potentiometer provides feedback on the position of the slide and a servo controls the flow rate into the silicone resonance chamber. The chamber can be tuned via a stepper motor that applies pressure, slightly altering the chamber’s frequency and pressure. An Arduino with Firmata allows the device to controlled easily from any host computer. A detailed writeup in PDF form is on the Hackday.io project page.
As you can imagine, simulating a human mouth is a daunting task and the number of variables meant that [iSax] ended up with something only vaguely trombone-like. While ultimately it didn’t turn out to be the astounding music machine that [iSax] hoped, it did end up being a fun feat of engineering we can appreciate and admire. Progress towards automatic brass instruments seems to be coming slowly as we saw similar results with this robotic trumpet. Maybe someday we’ll have robot brass sections, but not today.
The holiday season is here, and along with it comes Christmas music. Love them or hate them, Yuletide tunes are a simple fact of life each December. This year, [Derek Anderson] put a modern spin on a few classic melodies and listened to them via his set of self-playing chimes.
Inspired by [Derek]’s childhood Ye Merry Minstrel Caroling Christmas Bells (video), these chimes really bring the old-school Christmas decoration into the 21st century. Each chime is struck by a dedicated electromagnetically-actuated mallet, which is in turn controlled by an ESP32 running MicroPython.
The chimes play MIDI files, so you could, of course, play music unrelated to Christmas if you wanted to. And they even feature an OLED screen that displays what song is being played. For added flair, the entire thing is beautifully framed in black walnut, not to mention the custom-wound solenoids.
This project incorporated mechanical and electrical design, woodworking, 3D printing, programming, and song arrangement. It’s a wonder that [Derek] was able to create the entire product in the 40-80 hour time frame he estimated. (Though it looks like he had a bit of help.)
We always love to see projects like this, ones in which several disciplines get rolled together to create a beautiful finished piece.
At one end of the synthesizer world, there stands commercial instruments designed for the ultimate in sound quality and performance, tailored to the needs of professional musicians. On the other, there are weird, wacky prototypes and artistic builds that aim to challenge our conception of what a synth should be. The VOC-25 by [Love Hultén] falls firmly in the latter category.
The synth is built around the Axoloti Core, a microcontroller board set up for audio experimentation. Packing stereo DACs and ADCs, and MIDI input and output, it’s the perfect base for such a project. Loaded up with vocal samples, it’s played by a keyboard in a fairly typical sense. Where things get interesting is the panel containing 25 sets of plastic teeth. The teeth open and close when the user plays the corresponding note, thanks to a solenoid. Along with the clacking sound of the machinery and pearly whites themselves, it adds quite a creepy vibe to the piece.
With its clean pastel enclosure, we can imagine this piece as the star of an avant-garde filmclip, or merely something to terrify children at a Maker Faire. It’s a fun build, to be sure. We’ve seen some other great experimental synths over the years, too – this 48 Game Boy build comes to mind. Video after the break.