Touch Tone MIDI Phone And Vocoder Covers Daft Punk

September 6, 2022 by Donald Papp 3 Comments

[poprhythm]’s Touch Tone MIDI Phone is a fantastic conversion of an old touch tone phone into a MIDI instrument complete with intact microphone, but this project isn’t just about showing off the result. [poprhythm] details everything about how he interfaced to the keypad, how he used that with an Arduino to create a working MIDI interface, and exactly how he decided — musically speaking — what each button should do. The LEDs on the phone are even repurposed to blink happily depending on what is going on, which is a nice touch.

Of course, it doesn’t end there. [poprhythm] also makes use of the microphone in the phone’s handset. Since the phone is now a MIDI instrument with both a microphone and note inputs, it’s possible to use them together as the inputs to vocoder software, which he demonstrates by covering Around the World by Daft Punk (video).

We love how [poprhythm] explains how he interfaced to everything because hardware work is all about such details, and finding the right resources. Here’s the GitHub repository for the Arduino code and a few links to other resources.

We have seen MIDI phone projects before, and each one is always unique in its own way: here’s a different approach to converting a keypad phone to MIDI, and this rotary pulse-dial phone went in a completely different direction with the phone itself completely unmodified, using only external interfacing.

You can admire [poprhythm]’s Touch Tone MIDI Phone in action in the short videos embedded below, with each one showing off a different aspect of the build. It’s great work!

Continue reading “Touch Tone MIDI Phone And Vocoder Covers Daft Punk” →

Reactive Load For Amplifiers Teaches Lessons About Inductors

August 24, 2022 by Bryan Cockfield 26 Comments

The sound produced by any given electric guitar is shaped not just by the instrument itself but by the amplifiers chosen to make that sound audible. Plenty of musicians swear by the warm sound of amplifiers with vacuum tube circuits, but they do have some limitations. [Collin] wanted to build a reactive load for using tube amps without generating a huge quantity of sound, and it resulted in an interesting project that also taught him a lot about inductors.

The reactive load is essentially a dummy load for the amplifier that replaces a speaker with something that won’t produce sound. Passive loads typically use resistor banks but since this one is active, it needs a very large inductor to handle the amount of current being produced by the amplifier. [Colin] has also built a headphone output into this load which allows it to output a much smaller quantity of sound to a headset while retaining the sound and feel of the amplifier tubes, and it additionally includes a widely-used tone control circuit as well.

There’s a lot going on in the design of the circuitry for this amplifier load, including a lot of research into low-frequency inductors that can handle a significant amount of current. [Collin] eventually ended up winding his own, but the path he took to it was long and winding. There’s a lot of other circuit theory discussed as well especially with regards to the Baxandall EQ that he built into it as well. And, if you’d like to learn more about tube amplifiers in general, take a look at this piece which notes one of the best stereo amps ever produced.

Arduino Drum Platform Is Fast

June 28, 2022 by Bryan Cockfield 53 Comments

Drums are an exciting instrument to learn to play, but often prohibitive if there are housemates or close neighbors involved. For that problem there are still electronic drums which can be played much more quietly, but then the problem becomes one of price. To solve at least part of that one, [Jeremy] turned to using an Arduino to build a drum module on his own, but he still had to solve yet a third problem: how to make the Arduino fast enough for the drums to sound natural.

Playing music in real life requires precise timing, so the choice of C++ as a language poses some problems as it’s not typically as fast as lower-level languages. It is much easier to work with though, and [Jeremy] explains this in great detail over a series of blog posts detailing his drum kit’s design. Some of the solutions to the software timing are made up for with the hardware on the specific Arduino he chose to use, including an even system, a speedy EEPROM, hardware timers, and an ADC that can sample at 150k samples per second.

With that being said, the hardware isn’t the only thing standing out on this build. [Jeremy] has released the source code on his GitHub page for those curious about the build, and is planning on releasing several more blog posts about the drum kit build in the near future as well. This isn’t the only path to electronic drums, though, as we’ve seen with this build which converts an analog drumset into a digital one.

Continue reading “Arduino Drum Platform Is Fast” →

Doodlestation Is Beautifully Musical Furniture

June 18, 2022 by Lewin Day 7 Comments

Whether you’re a modular synth enthusiast or simply love the idea of rad electronic jams, we can all get behind the idea of crazy electronic instruments with buttons, dials, and patch cables galore. The Doodlestation is a wonderful example of that, built by [Love Hulten].

There’s a custom 37-key keyboard that lets one input musical notes in the typical way, along with a hilarious animated MIDI visualizer with a man that uses his mouth to shoot rainbows. There’s a theremin built into the chassis, too, allowing your hands to control the sound via the magic of the æther. Even better, there’s a custom-built tape echo in the upright section, and you even get to see the mechanical parts working and the mag ribbon wiggling about. That’s fun.

The custom hardware is joined by a series of off-the-shelf devices that add their own functionality to the mix. It includes a Sequential OB-6 analog synthesizer, a Moog DFAM drum module, and a Hologram Microcosm loop & glitch box for more noodling possibilities.

We love a good musical project around these parts; we’ve featured some great other projects for live electronic jams before, too. Video after the break.

Continue reading “Doodlestation Is Beautifully Musical Furniture” →

Behold The Mighty Floppotron 3.0

June 14, 2022 by Dave Rowntree 37 Comments

If anyone has been struggling to get hold of a 3.5″ floppy drive lately, we think we’ve got a clue as to why — behold, the mighty floppotron 3.0 by [Paweł Zadrożniak.] With an utterly bonkers 512 floppy drives, four flatbed scanners and sixteen hard disks of various sizes, the floppotron 3.0 MIDI synthesiser is possibly the biggest such retro hardware synthesiser so far. Since every part of the system is motor-based, nobody is going to be surprised that to power the show is quite an undertaking, with nearly twenty switched-mode PSU modules needed to keep up with the demand, averaging 300W but rated at 1.2kW peak!

A full custom MIDI-to-RS485 gateway based around the nRF52xx series MCU deals with the communication to the collection of instrument controllers. These controllers are generic enough to take RS485 input and control a dedicated driver for either an array of floppy drives (up to 192), an array of hard drives or the handful of scanners. The way the floppy drives are grouped is quite neat. Rather than using each drive to generate a specific tone, the software uses the whole column for each note. By varying the number of drives moving simultaneously over time, the sound volume varies, simulating the note envelope and giving a richer sound. Multiple columns driving in parallel give the system a 16-note polyphony. The floppies cover the low notes, with the four flatbed scanners covering the higher notes. MIDI drum sounds are mapped to the hard disks, operating in a, well, percussive manner, with different case shapes giving unique sounds. Even the firmware can be updated over MIDI! So, checkout the demo video after the break for a sweet rendition of the very familiar “Entry of the gladiators” by Czech composer Julius Fučík.

If you think this looks familiar, you’re not mistaken, we’ve covered an earlier floppotron before, but we reckon nobody has attempted to do it with ye olde eight-inch drives yet!

Continue reading “Behold The Mighty Floppotron 3.0” →

Live Floppy Music Adds Elegance To Any Event

June 9, 2022 by Tom Nardi 16 Comments

It wasn’t long after early humans started banging rocks together that somebody in the tribe thought they could improve on things a bit by doing it with a little rhythm. As such the first musician was born, and since it would be a couple million years before humanity figured out how to record sound, musical performances had to be experienced live throughout most of history. On the cosmic scale of things, Spotify only shows up about a zeptosecond before the big bash at midnight.

So its only fitting that [Linus Åkesson] has perfected the musical floppy drive to the point that it can now be played live. We understand the irony of this being demonstrated via the video below the break, but we think it still gets the point across — rather than having to get a whole array of carefully-scripted drives going to perform something that even comes close to a musical number, he’s able to produce tones by manipulating a single drive in real-time.

In his write-up, [Linus] not only goes over the general nuts and bolts of making music with floppy drives, but specifically explains how this Commodore 1541-II drive has been modified for its new life as a digital virtuoso. From his experiments to determine which drive moves corresponded to the most pleasing sounds, to the addition of a small microphone and a piezo sensor paired with an LMC662-based amplifier to provide a high-fidelity capture of the drive’s sounds and vibrations, there’s a lot of valuable info here for anyone else looking to make some sweet tunes with their old gear.

We’ve seen something of a resurgence of the floppy drive this year, with folks like Adafruit digging into the classic storage medium, and an experimental project to allow the Arduino IDE to create bootable x86 floppies. You won’t hear any complaints from us — while they might not offer much capacity compared to more modern tech, there’s something about a stack of multi-colored disks with hastily applied labels that warms our cold robotic hearts.

Continue reading “Live Floppy Music Adds Elegance To Any Event” →

Put Another Dime In The Jukebox

May 24, 2022 by Al Williams 19 Comments

We don’t always acknowledge it, but most people have an innate need for music. Think of all the technology that brings us music. For decades, most of the consumer radio spectrum carried music. We went from records, to tape in various forms, to CDs, to pure digital. There are entire satellites that carry — mostly — music. Piracy aside, people are willing to pay for music, too. While it isn’t very common to see “jukeboxes” these days, there was a time when they were staples at any bar or restaurant or even laundrymat you happened to be in. For the cost of a dime, you can hear the music and share it with everyone around you.

Even before we could record music, there was something like a jukebox. Coin-operated machines, as you’ll recall, are actually very old. Prior to the 1890s, you might find coin-op player pianos or music boxes. These machines actually played the music they were set up to play using a paper roll with holes in it or metal disks or cylinders.

Early Days

That changed in 1890 when a pair of inventors connected a coin acceptor to an Edison phonograph. Patrons of San Francisco’s Palais Royale Saloon could put a hard-earned nickel in the slot and sound came out of four different tubes. Keep in mind there were no electronic amplifiers as we know them in 1890. Reportedly, the box earned $1,000 in six months.

Continue reading “Put Another Dime In The Jukebox” →