Rocking A New Sound For Guitar

January 31, 2015 by Sarah Petkus 26 Comments

We’ve seen inventive sound hacking from [Jeremy Bell] before on Hackaday. You may remember reading a few months ago about how he invented a new way to produce that familiar effect DJs create when scratching records. By clipping samples from cassette tapes and stretching them across a set of short rails, he was able to refashion the audio pickup to glide over the tape at his fingertips. With a clothes pin wrapped in strips of foil teetering over a contact, he had a responsive tactile switch to aid in producing the cutting needed to carve out a beat.

Since then, [Jeremy] has been evolving this same switch concept and testing out new applications for it. The most recent of which he appropriately referrers to as the “Rocker”. With an electric guitar as a starting point, [Jeremy] uses a similar switching technique to bounce back and forth between two audio signals. The first of which being the sound produced in real-time by hammering on the frets of the guitar, and the second channel having a slight delay. By leveraging the glitchy effect created when switching between the two channels he is able to produce a sound all its own.

The prototype seen in his video is table-bound like the early versions of his Scrubboard, yet he’s able to play one-handed with the guitar and demo his device like a cake walk. It’d be fantastic to see this quirkiness and ingenuity taken to the level of his previous hack, leading to a stand-alone add-on for the guitar. Either way, this is yet another great example of sound play:

Continue reading “Rocking A New Sound For Guitar” →

Digitally Controlled Circuit Bending

January 30, 2015 by Brian Benchoff 16 Comments

Circuit bending doesn’t get a lot of respect around some parts of the Internet we frequent, but there is certainly an artistry to it. Case in point is the most incredible circuit bending we’ve ever seen. Yes, it’s soldering wires to seemingly random points on a PCB, but these bend points are digitally controlled, allowing a drum machine to transform between bent crunchiness and a classic 1980s drum machine with just a few presses of a touch screen controller.

All circuit bending must begin with an interesting piece of equipment and for this project, [Charles], the creator of this masterpiece of circuit bending, is using a Roland TR-626, a slightly more modern version of the TR-606, the percussive counterpart of the infamous TB-303. The circuit is bent in the classical fashion – tying signals on the PCB to ground, VCC, or other signals on the board. [Charles] then out does everyone else by connecting these wires to 384 analog switches controlled by an Arduino Mega. Also on the Arduino is a touch screen, and with a slick UI, this old drum machine can be bent digitally, no vast array of toggle switches required.

[Charles] has put up a few videos going over the construction, capabilities, and sound of this touch screen, circuit bent drum machine. It’s an amazing piece of work, and something that raises the bar for every circuit bending mod from this point on.

Thanks [oxygen_addiction] and [Kroaton] for sending this one in.

Continue reading “Digitally Controlled Circuit Bending” →

Is That A Tuner In Your Pocket…?

January 29, 2015 by Sarah Petkus 38 Comments

As a musician, it’s rare to consistently recognize with the naked ear whether or not a single instrument is in tune. There are a number of electronic devices on the market to aid in this, however if you’re leading into an impromptu performance to impress your friends, using one feels about as suave as putting on your dental headgear before bed. When tuning is necessary, why not do so in a fashion that won’t cramp your style?

To help his music-major friends add an element of Bond-like flare to the chore, [dbtayl] designed a chromatic tuner that’s disguised as a pocket watch, pet-named the “pokey”. The form for the custom casing was designed in OpenSCAD and cut from aluminum stock on a home-built CNC mill. Under its bass-clef bedecked cover is the PCB which was laid out in KiCad to fit the watch’s circular cavity, then milled from a piece of copped-clad board. The board contains the NXP Cortex M3 which acts as the tuner’s brain and runs an FFT (Fast Fourier Transform) that uses a microphone to match the dominant pitch it hears to the closest note. Five blue surface-mount LEDs on the side indicate how sharp or flat the note is, with the center being true.

[dbtayl’s] juxtaposition of circuitry in something that is so heavily associated with mechanical function is a clever play on our familiarity. You can see a test video of the trinket in action below:

Continue reading “Is That A Tuner In Your Pocket…?” →

3D Printed LED Guitar Chord Chart

January 18, 2015 by Adam Fabio 12 Comments

Learning to play guitar can involve a lot of memorization – chords, scales, arpeggios, you name it. [MushfiqM] has made the process a bit easier with his Digital Chord Chart. Just about every beginning guitarist keeps a chord app, chord book, or even a chord poster handy. Usually these chord charts are in the form of tablature, which is a shorthand method of showing where each finger should go on the instrument. [MushfiqM] took things a step further by actually placing that chart on a 3D printed model of a guitar fretboard.

[MushfiqM] started by rendering a 3D model of an abbreviated guitar using Autodesk Inventor. He then printed his creation in 3 parts: headstock, neck, and fretboard. The neck of the guitar was hollowed out to allow room for a matrix of LEDs which would show the finger positions. [MushfiqM] then painstakingly soldered in a charlieplexed matrix of 30 leds, all connected by magnet wire. The LEDs are controlled by an Arduino UNO, which has the chord and scale charts stored in flash.

For a user interface, [MushfiqM] used a 2×16 character based LCD and a low-cost IR remote control. All the user has to do is select a chord or scale, and it’s displayed on the fretboard.

There are a couple of commercial products out there which perform a similar function, most notably the Fretlight guitar. Those can get a bit pricy though – costing up to $400.00 USD for an LED enabled guitar.

[via Instructables]

Drums Anywhere!

January 16, 2015 by Bryan Cockfield 16 Comments

The students over at Cornell’s School of Electrical and Computer Engineering have been hard at it again with their senior projects. This time, it’s the very tiny and portable drumset dubbed Drums Anywhere by its creators [Shiva Rajagopal] and [Richard Quan]. Since there are other highly portable instruments like roll-up pianos, they suppose there should be a portable drum kit that actually sounds like drums, and this ECE duo have hit the metaphorical and physical drum on the head… except that this project doesn’t actually use physical drums to make sound.

The project consists of two 3D-printed box-like sensors with velcro straps that can be attached to any drumstick-shaped object that might be lying around. Inside the box is a flex sensor and a tiny microphone which report the “beats” to a microcontroller when they strike another object.

On the software side, there are two sampled sounds stored in the microcontroller but they plan to add more sounds in the future. The microcontroller outputs sound to a pair of speakers, and the sensors are sensitive to force, so the volume can range from almost inaudible all the way up to [John Bonham]-style booms. This could also be theoretically expanded to include more than two “beat boxes” for extra sounds, or be wireless. The options are virtually limitless, although the team notes that they are limited by the number of interrupts and ADC converters on their particular microcontroller, an ATmega1284.

This is another interesting take on a having drumset without the drums, and definitely expands the range of what a virtual drum set can do. It’s also great to see interesting projects coming from senior design classes! Be sure to check out the video after the break.

Continue reading “Drums Anywhere!” →

Organ Donor Gives Up A Leslie Speaker

January 14, 2015 by Rick Osgood 23 Comments

It was about ten years ago that [Richard] received an old musical organ. Moving to a new house meant it would be cumbersome to move the organ with him, so he opted to harvest some interesting components instead. Specifically, he kept the Leslie speaker.

A Leslie speaker is a special kind of speaker mechanism that creates a tremolo effect as well as a vibrato effect. You can hear this effect in [Richard’s] video below. Simple effects like this would be easy to do on a computer nowadays, but that wasn’t the case several decades ago. Before digital electronics, musical effects were often performed by analog means. [Richard’s] Leslie speaker is a small speaker behind of a Styrofoam baffle. The baffle spins around the speaker which changes the reflection angle of the sound, producing the musical effect.

[Richard] tried hooking this speaker up to other musical instruments but found that turning off the electric motor created an audible pop over the speakers. To remedy this, he build a simple “snubber” circuit. The circuit is just a simple 240 ohm resister and a 0.05 uF capacitor. These components give the transients a path to ground, preventing the pops and clicks when the motor is powered up. Now [Richard] can use this classic piece of audio equipment for newer projects. Continue reading “Organ Donor Gives Up A Leslie Speaker” →

Stereo Audio On A PIC32

January 11, 2015 by Bryan Cockfield 13 Comments

The PIC microcontrollers are powerful little devices, and [Tahmid] is certainly pushing the envelope of what these integrated circuits can do. He has built (for educational purposes, he notes) an audio player based on a PIC32 and a microSD card. Oh, and this microcontroller-based audio player can play in stereo, too.

The core of the project is a PIC32MX250F128B microcontroller. 16-bit 44.1kHz WAV files are stored on the microSD card and playback is an impressive 12-bit stereo audio. It can also play back 8-bit files (with some difficulty). [Tahmid] programmed the interface to work through the serial port and it is very minimalistic, mostly because this was a project for him to explore audio on a microcontroller and wasn’t to build an actual stand-alone audio player that he would use from day to day.

Still, even though the project isn’t ready to replace your iPod, the core audio-processing parts are already done if you want to try to build on [Tahmid]’s extensive work. You could even build a standalone audio player like this but have it play high-quality 12-bit stereo audio!

Continue reading “Stereo Audio On A PIC32” →