music

437 Articles

Professional Audio On An ESP32

October 6, 2019 by 53 Comments

Audiophiles have worked diligently to alert the rest of the world to products with superior sound quality, and to warn us away from expensive gimmicks that have middling features at best. Unfortunately, the downside of most high quality audio equipment is the sticker price. But with some soldering skills and a bit of hardware, you can build your own professional-level audio equipment around an ESP32 and impress almost any dedicated audiophile.

The list of features the tiny picoAUDIO board packs is impressive, starting with a 3.7 watt stereo amplifier and a second dedicated headphone amplifier. It also has all of the I/O you would expect something based on an ESP32 to have, such as I2S stereo DAC, an I2S microphone input, I2C GPIO extenders and, of course, a built-in MicroSD card reader. The audio quality is impressive too, and the project page has some MP3 files of audio recorded using this device that are worth listening to.

Whether you want the highest sound quality for your headphones while you listen to music, or you need a pocket-sized audio recording device, this might be the way to go. The project files are all available so you can build this from the ground up as well. Once you have that knocked out, you can move on to building your own speakers.

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How Many Commodores Does It Take To Crack A Nut?

September 7, 2019 by 19 Comments

It’s brilliant enough when composers make use of the “2SID” technique to double the channels in a Commodore 64 with two sound chips, but even then some people like to kick things up a notch. Say, five times more. [David Youd], [David Knapp] and [Joeri van Haren] worked together to bring us just that, ten Commodore computers synchronously playing a beautiful rendition of the Dance of the Sugar Plum Fairy at this year’s Commodore Retro eXpo.

The feat is composed of nine Commodore 64 computers and one Commodore 128, all fitted with the SID chip. It is a notorious synthesizer chip for utilizing both analog and digital circuitry, making each and every one of its revisions unique to a trained ear, not to mention impossible to faithfully reproduce in emulation. The SID was designed by Bob Yannes at MOS Technology, who later went on to co-found Ensoniq with his experience in making digital synthesizers.

How this orchestra of retro computers came to be, including details on how everything is pieced together can be found on this slideshow prepared by the authors of the exhibition. It’s interesting to note that because of timing differences in each computer’s crystal clock and how only the start of the song is synchronized between them, they can’t play long music tracks accurately yet, but a 90-second piece works just fine for this demonstration.

These synthesizer chips are slowly going extinct since they’re no longer being manufactured, so if you need a new replacement solution, FPGAs can fill that SID-shaped hole in your heart. If you need the whole computer though, the newer Teensy 3.6 will do just fine emulating it all. Check out this beast of a display in action after the break. While we’re at it, this isn’t the only time multiple 8-bit computers have been combined as an orchestra, though these Commodores sound a lot better than a table full of ZX Spectrums.

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Creative Limitation And The Super Nintendo Sound Chips

July 31, 2019 by 18 Comments

The Super Nintendo recently experienced a surge in popularity, either from a combination of nostalgic 30-somethings recreating their childhoods, or because Nintendo released a “classic” version of this nearly-perfect video game system. Or a combination of both. But what made the system worthy of being remembered at all? With only 16 bits and graphics that look ancient by modern standards, gameplay is similarly limited. This video from [Nerdwriter1] goes into depth on a single part of the console – the sound chips – and uses them to illustrate a small part of what makes this console still worth playing even now.

The SNES processed sound with two chips, a processing core and a DSP. They only had a capacity of 64 kb, meaning that all of a game’s sounds and music had to fit in this tiny space. This might seem impossible if you’ve ever played enduring classics like Donkey Kong Country, a game known for its impressive musical score. This is where the concept of creative limitation comes in. The theory says that creativity can flourish if given a set of boundaries. In this case it was a small amount of memory, and within that tiny space the composer at Rare who made this game a work of art was able to develop a musical masterpiece within strict limitations.

Even though this video only discusses the sound abilities of the SNES, which are still being put to good use, it’s a good illustration of what made this system so much fun. Even though it was limited, game developers (and composers) were able to work within its limitations to create some amazingly fun games that seem to have withstood the test of time fairly well. Not all of the games were winners, but the ones that were still get some playtime from us even now.

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A Simple Way To Analyze Guitar Pickups

July 29, 2019 by 21 Comments

To the uninitiated an electric guitar seems fairly simple: you pluck a string and the electronics send the corresponding audio signal on the 6.3 mm jack output, all ready for for the amplifier to work its magic. Much of what makes a guitar like that sound good depends on the pickups, however. These are the devices which are placed between the guitar body and the strings. Depending on the guitar there can be one, two, or more of them, of varying types and configurations.

As a Gibson fan who upon getting introduced to a Fender Telecaster just had to replace its pickups with humbucking types, [Ken Willmott] found himself thrown into the wonderful world of pickup design and characterization. After two years of working through a number of designs and approaches, he eventually settled on a preamplifier design featuring a JFET opamp (LT1058) on a custom PCB which amplifies the pickup response from a test signal, acting as a front end signal conditioner.

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Probability-Based Drummer Leaves The Beats Up To Chance

July 23, 2019 by No comments

Drum machines may seem like one of the many rites of passage for hardware makers, they’re a concept you can implement simply or take into the extreme making it as complex as you want. [Matt’s] DrumKid is one of them, and its long development history is wonderfully documented in the project logs.

[Matt’s] original intention was to use the automatic drummer as part of his band, wanting “the expressiveness of a good drummer but without the robotic tendencies of a simple drum machine”. For that, he created the first iteration of the DrumKid, a web-based project using the Web Audio API. The interface consisted of bars showing levels for different settings which could be intuitively tweaked, changing the probability of a drum sound being played. This gave the “drummer” its unpredictability, setting itself apart from any regular old drum machine.

Fast forward a few years, and [Matt] now wants to recreate his DrumKid as a proper piece of musical gear, porting the concept into a standalone hardware drum machine you can plug into your mixer. He decided to go with the Arduino framework for his project rather than the Teensy platform in order to make it cheaper to build. The controls are simplified down to a few buttons and potentiometers, and the whole thing runs off of three AAA batteries. Also, targeting the project for hardware like this allowed for new features to be added, such as a bit-crush filter.

We already saw the first prototype here on Hackaday when it was featured in a Hackaday Prize mentor session, and it’s nice to see how the project evolved since. After a number of revisions, the new prototype takes design cues from Teenage Engineering’s “Pocket Operator” drum machine, using the main PCB as its own faceplate rather than a 3D printed case in a familiar way we’ve seen before. Unfortunately, the latest board is non-functional due to a routing mistake, but you can see the previous working prototypes in his project logs.

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Getting MIDI Under Control

July 15, 2019 by No comments

When [Mr. Sobolak] started his DIY Midi Fighter he already had experience with the MIDI protocol, and because it is only natural once you have mastered something to expand on the success and build something more impressive, more useful, and more button-y. He is far from rare in this regard. More buttons mean more than extra mounting holes, for example an Arduino’s I/O will fill up quickly as potentiometers hog precious analog inputs and button arrays take digital ones. Multiplexing came to the rescue, a logic-based way to monitor or control more devices, in contrast to the serial protocols used by an IO expander.

Multiplexing was not in [Mr. Sobolak]’s repertoire, but it was a fitting time to learn and who doesn’t love acquiring a new skill by improving upon a past project? All the buttons were easy enough to mount but keeping the wires tidy was not in the scope of this project, so if you have a weak stomach when it comes to a “bird’s nest” on the underside you may want to look away and think of something neat. Regardless of how well-groomed the wires are, the system works and you can listen to a demo after the break. Perhaps the tangle of copper beneath serves a purpose as it buoys the board up in lieu of an enclosure.

We are looking forward to the exciting new versions where more solutions are exercised, but sometimes, you just have to tackle a problem with the tools you have, like when the code won’t compile with the MIDI and NeoPixel libraries together so he adds an Uno to take care of the LEDs. Is it the most elegant? No. Did it get the job done? Yes, and if you don’t flip over the board, you would not even know.

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Universal music translation network

Hiding Data In Music Might Be The Key To Ditching Coffee Shop WiFi Passwords

July 15, 2019 by 52 Comments

In a move guaranteed to send audiophiles recoiling back into their sonically pristine caves, two doctoral students at ETH Zurich have come up with an interesting way to embed information into music. What sounds crazy about this is that they’re hiding data firmly in the audible spectrum from 9.8 kHz to 10 kHz. The question is, does it actually sound crazy? Not to our ears, playback remains surprisingly ok.

You can listen to a clip with and without the data on ETH’s site and see for yourself. As a brief example, here’s twelve seconds of the audio presenting two versions of the same clip. The first riff has no data, and the second riff has the encoded data.

You can probably convince yourself that there’s a difference, but it’s negligible. Even if we use a janky bandpass filter over the 8 kHz -10 kHz range to make the differences stand out, it’s not easy to differentiate what you’re hearing:

After many years of performing live music and dabbling in the recording studio, I’d describe the data-encoded clip as having a tinny feedback or a weird reverb effect. However, you wouldn’t notice this in a track playing on the grocery store’s speaker. Continue reading “Hiding Data In Music Might Be The Key To Ditching Coffee Shop WiFi Passwords” →