Synthesizer Gets An External Touch Screen

July 8, 2020 by Tom Nardi 3 Comments

Like other owners of the high-end Yamaha MODX, [sn00zerman] wasn’t happy with the synthesizer’s integrated touch screen. It’s a bit small, and not at a very good angle for viewing. So he made it his mission to find some way of adding a larger external touch screen without making any permanent modifications to the expensive instrument.

This might seem like a tall order, but he wasn’t starting from zero. It was already known that you could plug an external display into it if you used a USB to DVI/HDMI adapter; but without the touch overlay it wasn’t a particularly useful trick. He pondered adding an external connector for the device’s built-in touch screen overlay, but that broke his no modifications rule. Considering how much one of these things cost, we can’t blame him for not wanting to put a hole in the side.

Sometimes you just have to dig out the right parts.

So he started to look for a software solution to get him the rest of the way. Luckily the MODX runs Linux, and Yamaha has made good on their GPL responsibilities and released the source code for anyone who’s interested. While poking around, he figured out that the device uses tslib to talk to the touch screen, which [sn00zerman] had worked with on previous projects. He realized that the solution might be as simple as finding a USB touch screen controller that’s compatible with the version of tslib running on the MODX.

In the end, a trip through his parts bin uncovered a stand-alone touch screen controller that he knew from experience would work with the library. Sure enough, when plugged into the MODX, the OS accepted it as an input device. With the addition of a USB hub, he was able to combine this with an existing display and finally have a more comfortable user-interface for his synthesizer.

Now all he’s got to do is plug in a USB floppy drive, and he’ll have the ultimate Yamaha Beat Laboratory.

Continue reading “Synthesizer Gets An External Touch Screen” →

Analog Noise Generator, Fighter Of Other Noises

July 6, 2020 by Donald Papp 11 Comments

A chaotic drone of meaningless sound to lull the human brain out of its usual drive to latch on to patterns can at times be a welcome thing. A nonsense background din — like an old television tuned to a dead channel — can help drown out distractions and other invading sounds when earplugs aren’t enough. As [mitxela] explains, this can be done with an MP3 file of white noise, and that is a solution that works perfectly well for most practical purposes. However he found himself wanting a more refined hardware noise generator with analog controls to fine tune the output, and so the Rumbler was born.

The Rumbler isn’t just a white noise generator. White noise has a flat spectrum, but the noise from the Rumbler is closer to Red or Brownian Noise. The different colors of noise have specific definitions, but the Rumbler’s output is really just white noise that has been put through some low pass filters to create an output closer to a nice background rumble that sounds pleasant, whereas white noise is more like flat static.

Why bother with doing this? Mainly because building things is fun, but there is also the idea that this is better at blocking out nuisance sounds from neighboring human activities. By the time distant music (or television, or talking, or shouting) has trickled through walls and into one’s eardrums, the higher frequencies have been much more strongly attenuated than the lower frequencies. This is why one can easily hear the bass from a nearby party’s music, but the lyrics don’t survive the trip through walls and windows nearly as well. The noise from the Rumbler is simply a better fit to those more durable lower frequencies.

[Mitxela]’s writeup has quite a few useful tips on analog design and prototyping, so give it a read even if you’re not planning to make your own analog noise box. Want to hear the Rumbler for yourself? There’s an embedded audio sample near the bottom of the page, so go check it out.

For a truly modern application of white noise, check out the cone of silence for snooping smart speakers.

DJing Without The Truckload Of Equipment; Secret Ingredient Is Raspberry Pi

July 3, 2020 by Jenny List 7 Comments

There is a romance to notions of a byegone age of DJing — driving a pair of Technics 1200s dwarfed on either side by the stacks, pumping techno bass through the laser-tinged darkness into a hungry crowd. Even if the reality of early evening Saturday wedding parties playing inoffensive crooners for the 50-somethings didn’t really live up to it.

The trouble with DJing old-style was that it required extensive logistics to shift all that equipment not to mention a record collection, so the modern DJ for whom everything has gone digital is truly lucky in the scale of their operation. For some people even that is too much to carry, and [Dennisdebel] has minimised a DJ rig to the next level, by running the popular Mixxx DJing software on a Raspberry Pi hooked up to his DJ controller. You can see the result in the video below the break.

This is more of a HOWTO for installing a set of software packages on the Pi to achieve an aim rather than a special hardware hack, but as he points out the interest lies in regaining control of the process. The DJ space is dominated by commercial offerings increasingly laden with DRM and proprietary cloud offerings, so this represents a means of taking back control of the process. If it’s not hacky enough, you can always add a home-made DJ mixing station.

Continue reading “DJing Without The Truckload Of Equipment; Secret Ingredient Is Raspberry Pi” →

A Baby Grand Gets MIDI

June 25, 2020 by Al Williams 10 Comments

Like a lot of people, [Jacques] doesn’t think a big hunk of plastic light enough to carry under your arm is a piano, even if it does have 88 keys. A piano is supposed to be a hefty piece of furniture that you have to buy people pizza to help you move. So he bought a used baby grand piano. It wasn’t in very good shape, though, so while restoring it, he also added MIDI to it. You can see the finished result in the video below.

At $100, the price was right, although it cost more to move it. Between water damage, moth attacks, and storage in a garage, the piano — an old Zimmerman — needed a lot of tender loving care. When it came to MIDI, [Jacques] found a used Disklavier — a very expensive piece of kit — but it didn’t fit the Zimmerman or another piano at hand. The solenoids and optical sensors are set up for a particular piano, so what can you do? Easy! Rebuild the bar that holds the solenoids and sensors.

Continue reading “A Baby Grand Gets MIDI” →

3D Printing Transmission Line Speakers

June 21, 2020 by Lewin Day 9 Comments

Anyone who has played with speakers on the workbench knows the huge difference enclosure design makes to the frequency response of an audio system. Speakerheads spend hours tinkering with designs and calculations, aiming to get the best out of a given set of drivers. [HexiBase] decided to try some experiments of his own, running into some hurdles along the way.

[Hexibase] aimed to 3D print a compact transmission line design, to suit a pair of 1 1/8″ full-range drivers. Being aware of the benefits of high-resolution resin 3D printing, he set out to print a design taking full advantage of the build volume of his Longer 3D Orange 30 printer. Unfortunately, after much fiddling with slicer settings, the printer turned out to have a fundamental fault, leading to unusable prints.

Undeterred, [Hexibase] switched to using his Longer FDM model instead. Printing out the enclosures in PLA. he noted that the different material will have a slightly altered frequency response than originally intended. Regardless, the final result sounds great, and barring some higher-frequency anomalies, the output correlates well with the mathematical model of expected performance.

3D printers make great tools for budding speaker builders, as they make constructing advanced geometries a cinch. Of course, you can even try and 3D print the drivers themselves if you’re so inclined. Video after the break.

Continue reading “3D Printing Transmission Line Speakers” →

Wurlitzer Note Visualizer Gets A 2020-Spec Replica

June 20, 2020 by Lewin Day 1 Comment

Way back in the 1970s, when smog laws were choking American V8s and the oil crisis was in full swing, Wurlitzer released their Key Note Visualizer. Intended as a teaching aid, the device lit up keys on a keyboard graphic, allowing an organ player to visually demonstrate their performance to a class. [Guy Dupont] set out to replicate this hardware, but with a modern twist.

The build consists of an ESP-32, which accepts MIDI data over Bluetooth Low Energy. This is then used to light up a series of RGB LEDs on a musical staff and a keyboard graphic, corresponding to the notes being played. The LEDs used are the old-school four-wire type, rather than more modern data-driven types. They’re placed in 3D-printed holders which serve to stop the light from each LED bleeding into adjacent areas. The faceplate is made of acrylic, stencilled with that classic orange paint and with vinyl decals applied for the markings. It’s all wrapped up in a walnut case, which [Guy] CNC machined himself.

It’s a tidy build that faithfully recreates the 1970s aesthetic of the original. We plaintively wish that manufacturers would release more electronics in walnut enclosures, though ask politely that they leave cheap veneer in the past where it belongs.

Of course, if you like your musical displays more abstract than instructional, try this giant oscilloscope visualisation on for size. Video after the break.

Continue reading “Wurlitzer Note Visualizer Gets A 2020-Spec Replica” →

Less Rock, More Roll: A MIDI Barrel Piano

June 18, 2020 by Sven Gregori 5 Comments

Strolling around a park, pedestrian zone, or tourist area in any bigger city is rarely complete without encountering the sound of a barrel organ — the perfect instrument if arm stamina and steady rotation speed are your kind of musical skills. Its less-encountered cousin, and predecessor of self-playing pianos, is the barrel piano, which follows the same playing principle: a hand-operated crank rotates a barrel, and either pins located on that barrel, or punched paper rolls encode the strings it should pluck in order to play its programmed song. [gabbapeople] thought optocouplers would be the perfect alternative here, and built a MIDI barrel piano with them.

Keeping the classic, hand-operated wheel-cranking, a 3D-printed gear mechanism rolls a paper sheet over a plexiglas fixture, but instead of having holes punched into it, [gabbapeople]’s piano has simple markings printed on them. Those markings are read by a set of Octoliner modules mounted next to each other, connected to an Arduino. The Octoliner itself has eight pairs of IR LEDs and phototransistors arranged in a row, and is normally used to build line-following robots, so reading note markings is certainly a clever alternative use for it.

Each LED/transistor pair represents a dedicated note, and to prevent false positives from neighboring lines, [gabbapeople] 3D printed little collars to isolate each of the pairs. Once the signals are read by the Arduino, they’re turned into MIDI messages to send via USB to a computer running any type of software synthesizer. And if your hands do get tired, you can also crank it with a power drill, as shown in the video after the break, along with a few playback demonstrations.

It’s always fun to see a modern twist added to old-school instruments, especially the ones that aren’t your typical MIDI controllers, like a harp, a full-scale church organ, or of course the magnificently named hurdy-gurdy. And for more of [gabbapeople]’s work, check out his split-flip weather display.

Continue reading “Less Rock, More Roll: A MIDI Barrel Piano” →