Build A Circuit Sculpture-Style VU Meter For Music

February 2, 2023 by Lewin Day 19 Comments

One of the coolest things any sound system can have is some kind of musical visualization. Thumping level meters that pump with the volume are a great example, and were particularly popular in the 1980s. Now, you can build a rainbow set with great response, thanks to this guide from [Invexlab World].

The build relies on a very simple circuit that relies entirely on analog electronics in lieu of the usual digital signal analysis usually employed for the job. It’s a barebones design that’s assembled using a jig to create the attractive circuit sculpture structure. It uses simple colored LEDs, assembled in a line with red at the bottom, stepping through yellow and green, to blue and white at the top. A series of diodes is placed in series, with the sound level having to exceed the voltage drop of successive diodes to light the higher LEDs. It’s intended to be directly connected to a speaker’s audio input, and thus likely does load down the amplifier output slightly.

The result is an attractive rainbow VU meter display that would look great as a part of any old-school stereo setup. We can imagine it would look even better if it was cast in clear resin. Video after the break.

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1000 Aluminium Cans Cast Into A Guitar

January 30, 2023 by Lewin Day 31 Comments

Aluminium cans are all around us, and are one of readily recyclable. While you can turn them into more cans, [Burls Art] had other ideas. Instead, he turned roughly 1000 cans into a custom aluminium guitar.

Both the body and neck of the electric guitar are made out of aluminium. It’s an impressive effort, as manufacturing a usable neck requires care to end up with something actually playable when you’re done with it.

Producing the guitar started with a big propane furnace to melt all the cans down so they could be cast into parts for the guitar. 38 lbs of cans went into the project, and were first dried out before being placed into the furnace for safety reasons. Aluminium cans aren’t made of the best alloy for casting, but you can use them in a pinch. The cans were first melted down and formed into ingots to be later used for producing the neck and body.

[Burls Art] then built sand casting molds for his parts with a material called Petrobond. Wood plugs were used to form the sand into the desired shape. The neck casting came out remarkably well, and was finished with a grinder, hacksaw, and sandpaper to get it to the right shape and install the frets. The body proved more difficult, with its multiple cavities, but it came together after a second attempt at casting.

Fully kitted out with pickups and hardware, the finished product looks great, and weighs 12.3 pounds. It sounds remarkably like a regular electric guitar, too. It does pick up fingerprints easily, and does have some voids in the casting, but overall, it’s a solid effort for an all-cast guitar.

We’ve seen some other great casting projects over the years before, too. Video after the break.

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Lego Guitar Is Really An Ultrasonically-Controlled Synth

January 26, 2023 by Lewin Day 4 Comments

The phrase “Lego Guitar” can be a stressful one to hear. You might imagine the idea of strings under tension and a subsequently exploding cloud of plastic shrapnel. This build from the [Brick Experiment Channel] eschews all that, thankfully, and is instead a digital synth that only emulates a guitar in its rough form factor.

The heart of the build is a Lego Mindstorms EV3 controller. It’s acts as the “body” of the guitar, and is fitted with a Lego “fretboard” of sorts. A slide is moved up and down the fretboard by the player. The EV3 controller detects the position of the slide via an ultrasonic sensor, and uses this to determine the fret the user is trying to play. The button the user presses on the controller then determines which of five “strings” the user is playing, and the selected note is sounded out from the EV3’s internal speaker. It’s strictly a monophonic instrument, but three different sounds are available: a bass guitar, a rock guitar, and a solo guitar, with all the fidelity and timbre of a 90s Casio keyboard.

It’s a fun and silly instrument, and also kind of difficult to play. The slide mechanism doesn’t offer much feedback, nor are the EV3 buttons intended for dynamic musical performance. Regardless, the player belts out some basic tunes to demonstrate the concept. We doubt you’d ever be able to play Through The Fire and Flames on such a limited instrument, but [Brick Experiment Channel] used their editing skills to explore what that might sound like regardless.

We’ve seen some other great synth guitars before, too. Modern microcontrollers and electronics give makers all kinds of creative ways to build electronic instruments with unique and compelling interfaces. Some are more successful than others, but they’re all fun to explore. Video after the break.

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Sequencing The Vintage Way

January 24, 2023 by Jenny List 5 Comments

For most of us, an 8-bit microcomputer means one of the home computers which set so many of us on our way back in the 1980s. But this ignores an entire generation of 1970s 8-bit machines which filled the market for affordable office and industrial desktop computing before we were seduced by Pac-Man or Frogger. It’s one of these, an SWTPC 6809, that’s found its way into the hands of [Look Mum No Computer], and in direct contradiction to his branding, he’s used it to control a synthesizer.

As you’d expect from the name, the computer hides a 6809 processor, and comes from the end of the 1970s when that chip had been released in an effort to stave off the market threat from the likes of Zilog and MOS Technologies. It has an SS-50 bus motherboard, and the saga in the video below the break is as much about the production of a custom DAC and trigger port for it to drive the synth as it is about troubleshooting a four-decade-old computer. It’s a credit to SWTPC that the machine is largely working after all this time, however it succumbs to some damage during the development of the interface.

At the end though, there’s a fully functional sequencer on a 1970s computer, playing some pretty good electronic music from an analogue synth. This is EXACTLY the future we were promised, back in 1979!

Long-time readers will know this isn’t the first SWTPC that has graced these pages.

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Arduino Synthesizer Uses Modified Slide Pots

January 6, 2023 by Kristina Panos 7 Comments

There comes a point in every Arduino’s life where, if it’s lucky, it becomes a permanent fixture in a project. We can’t think of too many better forever homes for an Arduino than inside of a 3D-printed synthesizer such as this 17-key number by [ignargomez] et al.

While there are myriad ways to synthesizer, this one uses the tried-and-true method of FM synthesis courtesy of an Arduino Nano R3. In addition to the 17 keys, there are eight potentiometers here — four are used for FM synthesis control, and the other four are dedicated to attack/delay/sustain/release (ADSR) control of the sound envelope.

One of the interesting things here is that [ignargomez] and their team were short a few regular pots and modified a couple of slide pots for circular use — we wish there was more information on that. As a result, the 3D printed enclosure underwent several iterations. Be sure to check out the brief demo after the break.

Don’t have any spare Arduinos? The BBC Micro:bit likes to make noise, too.

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Dittytoy recreation of Jean-Michel Jarre's Oxygene Part IV

Generative Music Created In Minimalistic Javascript Code

January 2, 2023 by Joseph Long 10 Comments

Dittytoy user [srtuss] has recreated one of the most influential works of electronic music in an elegant nineteen kilobytes of Javascript code. The recreation of Jean-Michel Jarre’s Oxygene Part IV on the Dittytoy platform, currently in beta, plays live right in your browser. Dittytoy empowers users to create generative music online using a simple Javascript API. Syntax of the API is loosely based on that of Sonic Pi, a code-based music creation and performance tool.

“Oxygene (Part IV)” was recorded by Jean-Michel Jarre in 1976. It was Jarre’s most successful single, charted on the top ten in several countries, and was more recently featured in the Grand Theft Auto IV video game. In the 1990s, famed electronic music innovator Brian Eno used the term “generative music” to describe music generated by an electronic system comprising ever-changing elements that may be algorithmic or random.

Recreation of Jarre’s work required modeling the Korg Minipops 7 drum machine, one of the instruments presented in our slew of open-source synthesizers.

Beat Backing Box For Bassists

December 23, 2022 by Bryan Cockfield 9 Comments

The soul of a rock band is its rhythm section, usually consisting of a drummer and bass player. If you don’t believe that, try listening to a band where these two can’t keep proper time. Bands can often get away with sloppy guitars and vocals (this is how punk became a genre), but without that foundation you’ll be hard pressed to score any gigs at all. Unfortunately drums are bulky and expensive, and good drummers hard to find, so if you’re an aspiring bassist looking to practice laying down a solid groove on your own check out this drum machine designed by [Duncan McIntyre].

The drum machine is designed to be as user-friendly as possible for someone who is actively playing another instrument, which means all tactile inputs and no touch screens. Several rows of buttons across the top select the drum sounds for the sequencer and each column corresponds to the various beats, allowing custom patterns to be selected and changed rapidly. There are several other controls for volume and tempo, and since it’s based on MIDI using the VS1053 chip and uses an STM32 microcontroller it’s easily configurable and can be quickly interfaced with other machines as well.

For anyone who wants to build their own, all of the circuit schematics and code are available on GitHub. If you have an aversion to digital equipment, though, take a look at this drum machine that produces its rhythms using circuits that are completely analog.

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