Musical Hacks

1382 Articles

This Synth Plays The Only Scale Everybody Knows

October 24, 2018 by 19 Comments

[randomprojectlab] is building a synthesizer around the pentatonic scale for the Hackaday Prize. It’s the Pentasynth, and it’s basically just a keyboard with five notes per scale.

There’s something common to every form of music. Nearly every musical tradition, from western art music, to Indonesian folk music makes use of a pentatonic scale. This is just a major scale without fourth and seventh scale degrees, or just playing the black keys on a piano.  It’s the one scale everybody knows, and forms the basis of every school of thought for music education. Noodling over the pentatonic scale is what all the cool guys do in Guitar Center. It’s absolutely the foundation of all music.

The hardware for this build is an Adafruit Metro Mini, or basically an Arduino with an ATMega328. This generates three channels of audio, two square waves — one each for the keyboard and bass accompaniment — and a pseudo-random noise drum beat. The keys are 3D printed, and the enclosure is CNC’s acrylic.

Most educational music toys out there have a few additional bits to make composing music easier. The Pentasynth is no exception, with a button that adds a drum beat, a button that adds a bassline, and a switch that makes the keyboard major or minor. It’s a great idea, and you can check out a video of the Pentasynth in action below.

Continue reading “This Synth Plays The Only Scale Everybody Knows” →

One Man’s Quest To Build His Own Speakers

October 23, 2018 by 49 Comments

Why build your own stereo speakers? Some people like to work on cars in their garage. Some people build fast computers. Others seek the perfect audio setup. The problem for a newcomer is the signal to noise ratio among audiophile experts. Forums are generally filled with a vocal group of extremists obsessing on that last tiny improvement in some spec.  It can be hard for a beginner to jump in and learn the ropes.

[Ynze] had this problem. He’d finished a custom amplifier and decided to build his own speakers. He found a lot of spirited debates about what was important for good speakers. He tried to wade through the discussions and determine which things had real practical value. The results and his speaker build are documented in a post that you’ll want to check out if you would like to design and build your own speakers.

Some of the topics ranged from solder type to capacitor construction and 700 Euro capacitors. [Ynze’s] goal was to build something that sounded good while keeping costs in line. He claims he spent about 250 Euro and wound up with speakers equivalent to 750 Euro store-bought speakers.

Continue reading “One Man’s Quest To Build His Own Speakers” →

Racing The Beam And Dropping Some Beats

October 23, 2018 by 5 Comments

The heart of the Atari 2600 wasn’t the 6502 (or the 6507 for the pedants), it was the TIA chip. This is the chip responsible for drawing graphics on the display, racing the beam, and extremely limited support for sound generation. We haven’t seen many attempts of using the Atari 2600 for chiptunes, but that doesn’t mean it can’t be done. [John Sutley]’s Syndrum, a take on an Atari 2600 drum machine is nearly a work of art. It’s a custom cartridge for the wood-paneled Atari, and an impressive input device that turns this classic console into a beat machine

Did the Atari 2600 ever come with a drum machine cartridge? Maybe. Probably not. [John] originally built this project to experiment with the TIA chip, but found it was less tonal than a kazoo. That struck ‘Atari synthesizer’ off the list and replaced it with an ‘Atari drum machine’. There are two key parts of the build here, the first being a repurposed Asteroids cartridge that had the PROM replaced with a ZIF socket. This allows [John] to easily burn new code to an EEPROM, stuff it in the socket, and run it on the Atari. All the code was developed with batari Basic, a BASIC-inspired language that spits out .bin files for the Atari.

But running code on the Atari is just one half of this build. To do a drum machine, you somehow need to tell the Atari when to play each sound. Given the lack of expansion capabilities for the Atari, [John] turned to the controller port. The Syndrum uses Arduino Nano to bridge the DE9 controller connector to a MIDI port. Yes, it’s real MIDI, on a machine that could probably never do MIDI natively (although we’d love to see someone try).

Need a video of this mind-blowing hack in action? Here you go:

Continue reading “Racing The Beam And Dropping Some Beats” →

The Spirit Of The 80s Lives On In A MIDI Harmonica

October 23, 2018 by 2 Comments

In the 1980s, there was a synthesizer that you could play like a harmonica. This device was called the Millioniser 2000. It utilized HIP (Harmonica In Principle) technology. The Millioniser 2000 was a breath controller wrapped in chrome-colored plastic embossed with its logo in an odd, pre-vaporwave aesthetic, and connected to a gray and green sheet metal enclosure loaded up with DIN jacks. The Millioniser 2000 is absolutely the pinnacle of late 70s, early 80s design philosophy. If it were painted brown, the Universe would implode.

Because of the rarity and downright weirdness of a harmonica synthesizer from the 80s, prices on the used market are through the roof. Musicians are a weird bunch. However, this does give someone the opportunity to recreate this bizarre instrument, and that’s exactly what [John Lassen] did for his entry for the Hackaday Prize.

While this isn’t as complex as the Millioniser 2000, it does have the same basic user interface. There’s a pressure sensor that measures how much you’re blowing. There’s a slider to change which notes are played, and there are a few buttons to change parameters, like the MIDI channel, a midi controller, or a transpose function. The electronics, like so many of the entries to the Musical Instrument Challenge in the Hackaday Prize, are built around the Teensy and it’s incredible audio library.

The HackadayPrize2018 is Sponsored by:

Robot + Trumpet = Sad Trombone.mp3

October 22, 2018 by 13 Comments

[Uri Shaked] is really into Latin music. When his interest crescendoed, he bought a trumpet in order to make some energetic tunes of his own. His enthusiasm flagged a bit when he realized just how hard it is to get reliably trumpet-like sounds out of the thing, but he wasn’t about to give up altogether. Geekcon 2018 was approaching, so he thought, why not make a robot that can play the trumpet for me?

He scoured the internet and found that someone else had taken pains 20 years ago to imitate embouchure with a pair of latex lips (think rubber glove fingers filled with water). Another soul had written about measuring air flow with regard to brass instruments. Armed with this info, [Uri] and partners [Ariella] and [Avi] spent a few hours messing around with air pumps, latex, and water and came up with a proof of concept that sounds like—and [Uri]’s description is spot-on—a broken robotic didgeridoo. It worked, but the sound was choppy.

Fast forward to Geekcon. In a flash of brilliance, [Avi] thought to add capacitance to the equation. He suggested that they use a plastic box as a buffer for air, and it worked. [Ariella] 3D printed some fingers to actuate the valves, but the team ultimately ended up with wooden fingers driven by servos. The robo-trumpet setup lasted just long enough to get a video, and then a servo promptly burned out. Wah wahhhh. Purse your lips and check it out after the break.

If [Uri] ever gets fed up with the thing, he could always turn it into a game controller a la Trumpet Hero.

Continue reading “Robot + Trumpet = Sad Trombone.mp3” →

Turning The Deep Note Into A Game

October 21, 2018 by 13 Comments

One of the most famous pieces of computer-generated music is the Deep Note, the audio trademark for THX. It begins with a dozen or so voices, randomly tuned between 200 and 400 Hz, then glissandos to a frequency spread of three octaves. Put that through a few thousand watts of a speaker system, play it before Jedi, and the audience will be listening.

The original THX Deep Note was created on hundreds of thousands of dollars worth of hardware running 20,000 lines of code, but that was in 1983. Now we have cheap microcontrollers, so of course, you can now fit the Deep Note in your pocket. You can even make it a game. That’s exactly what [Bob] did with his Deep Synth. It’s the Deep Note, in a Game Boy-ish format.

The hardware for this build is the 1Bitsy 1UP, a retro-inspired handheld game console from [Bob]’s friend [Pitor]. Onboard the 1Bitsy is an STM32 F4 running at 168 MHz with a 2.8″ LCD, SD card reader, and the traditional Game Boy control scheme. All the games are up to you.

[Bob] wrote an audio driver for the 1UP, but needed a good audio demo. Since the Deep Note was a good enough demo for Lucasfilms, it would obviously be a good enough demo for a microcontroller. In far less than 20,000 lines of code, [Bob] made the 1UP polyphonic, and it was surprisingly fast enough to synthesize around thirty oscillators. It actually sounds like the Deep Note, too. You can check out a video (and audio) of that after the break.

Continue reading “Turning The Deep Note Into A Game” →

Elegant Drum Machine From Teensy

October 20, 2018 by 7 Comments

Playing the drums is pretty hard, especially for the uncoordinated. Doing four things at the same time, all while keeping an even tempo, isn’t reasonable for most of us. Rather than hiring a drummer for your band who is well versed in this art, though, you might opt instead to outsource this job to a machine instead. It’s cheaper and also less likely to result in spontaneous combustion.

This drum machine is actually a MIDI Euclidean sequencer. Euclidean rhythms are interesting in their own regard, but the basics are that a common denominator between two beats is found in order to automatically generate complicated beats. This particular unit is running on a Teensy 3.5 and consists of four RGB rotary encoders, an SSD1306 LCD, four momentary buttons, and four 16 LED Neopixel rings. Setting each of the dials increases the number of beats for that particular channel, and it can be configured for an almost limitless combination of beats and patterns.

To really get a feel of what’s going on here, it’s worth it to check out the video after the break. MIDI is also a fascinating standard, beyond the fact that it’s one of the few remaining standards created in the 80s that still enjoys active use, it can also be used to build all kinds of interesting instruments like one that whacks wine glasses with mallets or custom synthesizers.

Thanks to [baldpower] for the tip!

Continue reading “Elegant Drum Machine From Teensy” →