Stick Your Own Samples In The Cheetah SpecDrum

May 21, 2019 by Lewin Day 10 Comments

The Sinclair ZX Spectrum was a popular computer in the 8-bit era, and particularly so in its homeland of the United Kingdom. It was known more for its low cost than its capabilities, but it gained many add-ons over the years. One of those was the Cheetah SpecDrum, which turned the Spectrum into a rudimentary drum machine. [PianoMatt] wasn’t happy with the original drum samples, so he set about loading a custom kit into the SpecDrum.

The SpecDrum software initially came with extra sample tapes, so [PianoMatt] knew it was an achievable task to load in custom samples. Starting by loading the software in an emulator, the RAM was then exported as raw data and loaded up in Audacity. After some experimentation, it was determined the samples were stored in 8-bit format at a sample rate of approximately 20 kHz. With this figured out, it was then possible to load replacement samples directly into RAM through the emulator.

However, this wasn’t enough for [PianoMatt]. Further digging enabled him to reverse engineer the format of the replacement sample tapes. Armed with this knowledge, [PianoMatt] then generated his own tape, complete with proper headers and labels for each drum sound.

It’s a tidy effort to bring a more modern sound to a now positively ancient piece of hardware. We’d love to hear a track with drums courtesy of the SpecDrum, so we’ll keep an ear out on Soundcloud. Mucking around with old sound hardware is a popular pastime in these parts – we’ve even seen people go so far as to build bespoke Sega chiptune players from scratch.

The Rhysonic Wheel Automates Live Music

May 18, 2019 by Bryan Cockfield 10 Comments

Making waves in the music world is getting harder. Almost anyone who has access to the internet also has access to a few guitars and maybe knows a drummer or can program a drum machine. With all that competition it can be difficult to stand out. Rather than go with a typical band setup or self-producing mediocre rap tracks, though, you could build your own unique musical instrument from scratch and use it to make your music, and your live performances, one-of-a-kind.

[Pete O’Connell]’s instrument is known as the Rhysonic Wheel, which he created over the course of a year in his garage. The device consists of several wheels, all driven at the same speed and with a common shaft. At different locations on each of the wheels, there are pieces of either metal or rubber attached to strings. The metal and rubber bits fling around and can strike various other instruments at specified intervals. [Pete O’Connell] uses them to hit a series of percussion instruments, a set of bells, and even to play a guitar later on in the performance.

While it looks somewhat dangerous, we think that it adds a level of excitement to an already talented musical performance. After all, in skilled hands, any number of things can be used to create an engaging and unparalleled musical performance with all kinds of sounds most of us have never heard before.

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MIDI Synthesizer From A Sega Genesis

May 15, 2019 by Bryan Cockfield 14 Comments

[Aidan] is really into FM synthesis chips for creating audio, and one of the most interesting chips from that era is found on the Sega Genesis. Anyone involved in the console wars at that time certainly remembers the classic, unique sound that those video game systems were able to produce, so [Aidan] built a device using a sound chip from a Genesis to play any piece of music from any game. The second iteration of that project, though, is able to use those same sound files as a MIDI synthesizer.

The interesting aspect of these chips is how they use registers to change the audio output. Essentially, there is a complicated register map (one section of his write-up is simply called “Register Hell”) that can be called in order to access the various types of effects one would normally see on a synthesizer. It’s not straightforward at all, though, and got even more complicated once [Aidan] started adding MIDI functionality to it as well. Once he finished sifting through the Sega Genesis technical manuals and a bunch of registers, though, he had a unique synthesizer working that doesn’t sound like anything you’ve ever heard, unless you’ve ever played a Genesis.

If you’d like to check out his first project, the MegaBlaster, which plays the sound files of the old Genesis games directly, we featured that a while ago. Keep in mind though that his latest project isn’t just an updated MegaBlaster, though. He built this entire thing from the ground up.

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The Sampler That Fits In Your Pocket

May 7, 2019 by Brian Benchoff 5 Comments

The future of the music instrument industry lies in synthesizers, and nowhere is this more apparent than the suite of tiny, pocket-sized synths more than capable of making bleeps and bloops. You’ve got tiny Korgs and Pocket Operators, and the time is ripe for people to wake up to tiny, pocket-sized synths.

The latest in a wide, diverse range of pocketable synthesizers is the Bitty. It’s a pocket-sized drum machine that’s the closest we’ve seen to a pocketable MPC to date. It’s a Kickstarter project that’s already completely funded only a day into the campaign.

The core of the Bitty is built around the Arduino, and for good reason. The last few years have seen some incredible advances in Arduino audio libraries, and this is no exception. The Bitty is built around the Mozzi library that gives it actual oscillators and ready-made wavetables. The Bitty comes with ‘software packs’ that include the Theremin Bitty, Techno Bitty, Basement Bitty, Trap Bitty, Lofi Bitty Bitty, and Beach Bitty. All of these are different sounds and samples, turning this tiny device into an all-in-one sampling solution. Seriously: look at how many Pocket Operators there are, how much they sell for, and realize this is a device that can download new samples and sounds. There’s a market here.

The Arduino-compatible Bitty is available on Kickstarter right now, with the base reward starting at under $100, with delivery in February, 2020. You can check out the video demo below.

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Marvelously Machined Clutch Masters Musical Marble Machine Mayhem

May 1, 2019 by Lewin Day 29 Comments

As far as marble runs go, few can hope to compete with [Wintergatan]’s amazing musical works. While undertaking the build of the Marble Machine X, timing problems became apparent. You can crank the machine faster or slower to alter the tempo, but the time it took marbles to drop due to gravity and hit an awaiting drum remains constant. You can’t control gravity, so you look to a mechanical solution in adjusting marble drops. In music, as in a jewel heist, timing is everything. Thankfully, [Machine Thinking] was on hand to collaborate, and a solution was found in the form of a beautifully machine indexable clutch.

The duo came together and designed a clutch, that would allow the timing relationship between various parts of the Marble Machine X to be varied. At 7:10 into the Wintergatan video below he gets down to brass tacks on how this brass music timing clutch actually works. At 90 BMP, the clutch allows the synchronization of the machine to be altered in approximately 10ms increments. Without this vital addition, drum beats would tend to slip out of time.

It’s a part that would challenge the novice, requiring the cutting of teeth and the inscription of accurate markings to allow it to do its job. However, it’s no trouble for [Machine Thinking], who shared a video of the machining process, including the outsourcing of the hand-engraved dial numbers.

Such a piece takes significant work to produce, and yet it is just one part of a much larger machine. We can’t wait to see the Marble Machine X finished, but if you’re unfamiliar with [Wintergatan]’s earlier works — you’re in for a treat.

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Junkbox MIDI

April 27, 2019 by Brian McEvoy No comments

Do you ever peer into the void…of your hardware scrap box? It may be a wonderland of parts with near-infinite potential, and they just need to be assembled and depending on what you hoard, programmed. Access to a laser engraver doesn’t hurt either. The stuff in [Mr. Sobolak]’s bin is cooler than average, at least by Hackaday writer standards. His sound palette project is a wild mixture of interfaces, hardware, channels, and color. There are arcade pushbuttons, slider potentiometers, rotary potentiometers, miniature laser harp, touch piano, and drum pads which earns the title of junk box build extraordinaire.

Under the hood, we find the usual copper tape, wire and solder connecting operators to a Teensy 3.2. In the more esoteric part of the BOM, we find some fancy SoftPots which look like great fun to play. All the code is linked in the Instructable, but there is absolutely no reason to make an exact copy. MIDI is from the 80s and libraries abound for this protocol so the building may be the hardest part of making an interface that fits your character. Some of the techniques in the Instructable may help you, like how to connect a piezo element so it can read something lighter than a wrecking ball or the laser harp roughly the size of your palm.

We are not short of MIDI interfaces if you are thinking of making your own or be truly random.

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A Tesla Coil From PCBs

April 25, 2019 by Jenny List 6 Comments

While at the Hacker Hotel camp in the Netherlands back in February, our attention was diverted to an unusual project. [Niklas Fauth] had bought along a Tesla coil, but it was no ordinary Tesla coil. Instead of the usual tall coil and doughnut-shaped capacity hat it took the form of a stack of PCBs with spacers between them, and because Tesla coils are simply cooler that way, he had it playing music as an impromptu MIDI-driven plasma-ball lousdpeaker. Now he’s been able to write up the project we can take a closer look, and it makes for a fascinating intro not only to double-resonant Tesla coils but also to Galium Nitride transistors.

The limiting factor on Tesla coils comes from the abilities of a transistor to efficiently switch at higher frequencies. Few designs make it above the tens of kHz switching frequencies, and thus they rely on the large coils we’re used to. A PCB coil can not practically have enough inductance for these lower frequencies, thus Niklas’ design employs a very high frequency indeed for a Tesla coil design, 2.6 MHz with both primary and secondary coils being resonant. His write-up sets out in detail the shortcomings of conventional MOSFETS and bipolar transistors in this application, and sets out his design choices in using the GaN FETs. The device he’s using is the TI LMG5200 GaN half-bridge driver, that includes all the necessary circuitry to produce the GaN FET’s demanding drive requirements.

The design files can be found in a GitHub repository, and you can see a chorus of three of them in action in the video below. Meanwhile [Niklas] is a prolific hardware hacker whose work has appeared on these pages in the past, so take a look at his ultrasonic phased array and his x-ray image sensor work.

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