LaunchPad MIDI Synth

February 13, 2011 by Mike Nathan 6 Comments

launchpad_midi_synth

[NatureTM] sent in a writeup for the MIDI synthesizer he recently built using a TI LaunchPad. The construction is pretty simple overall, consisting of little more than the MSP430, a handful of resistors, and an optoiosolater. Of course, a MIDI controller is required, but he already had that on hand.

Once the MIDI data is read from the optoisolator, his code takes care of the rest, adjusting the square wave sound generator to get the proper note. He does mention that since the synthesizer is monophonic, special care is taken to ensure that simultaneous notes are processed properly. You can route all of the sound into a single speaker, but he used the optoisolator to send the sound data to multiple LaunchPads instead, resulting in a fun little MIDI quintet.

He provides code and plenty of video on his site, but keep reading for a sneak peek of his synth in action.

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Theremin Midi Board Is Like Using Autotune

February 8, 2011 by Mike Szczys 8 Comments

[Steve Hobley] built a Theremin interface board that tracks pitch and volume. Using this setup he’s able to pass data over a midi interface which effectively converts the instrument into a non-contact midi controller. As we joked in the headline, this does allow for the use of autotune, by snapping notes that are sharp or flat to the center of the nearest pitch. But you should watch the video after the break to see [Steve] show off the other features as well. A keyboard can be used to seed a starting pitch, with arpeggios of several different tonalities built on top of it based on the input from the Theremin.

Want the details? Unfortunately you’ll have to pay for the schematics. But the concept is still just as interesting to read about, even if you don’t know what went into the system. Continue reading “Theremin Midi Board Is Like Using Autotune” →

Homebrew Mp3 Player With Some Bonus Features

February 4, 2011 by Kevin Dady 16 Comments

When [falldeaf] set about making his own homebrew Mp3 player, he ended up at the same place we most do while looking into the subject, the wonderful Minty Mp3. Basing the design on [Adafruit Industries] popular board, we are presented The Mp3 Garbler.

First change of the project was to replace the sometimes difficult to find ST013, or the more expensive ST015T Mp3 decoder chip, and the CS4340 digital to analog cconverter with a single vs1001k, which we have checked out before. And while yes VLSI says that the 1001 series is a discontinued product, and it may be a bit hard to find now days, they also offer an updated model on their website, which should suit the application fine.

Next up is a useful LCD display sporting a Sparkfun lcd backpack, that shows us all the important to know music info. And finally there is a 10×14 led matrix display, that can be used to display all sort of user feedback icons, and is driven by a MAX6953, which we think is a pretty spiffy chip.

While there is no schematic, there are brd files, and source code available for your PIC18F452 or similar micro controller to complete your own

MIDI Input For The Kaossilator

February 4, 2011 by Mike Szczys 7 Comments

This isn’t strictly a MIDI input hack; [Furrtek] pulled off an alternate input hack for the Kaossilator that he’s currently using with a MIDI connection. In its unhacked form the Kaossilator is a small touchpad-based sound manipulation tool. [Furrtek] sniffed out how the touchpad data is read and used on the little device. He then purposed an ATtiny2313 as the core of a circuit that spoofs those signals. The microcontroller now listens for incoming MIDI data, looks up the proper signal translations in a table, then outputs them to the Kaossilator.

In the video after the break you can see that it works perfectly, with no lag or noticeable problems. As we alluded to at the top, there could be so much more done with this. Since the ATtiny2313 is merely translating MIDI into touchpad signals, the input could be anything. The first thing that comes to mind is a dance floor that changes the music based on how many people are out there tearing it up. Continue reading “MIDI Input For The Kaossilator” →

LEGO Wah-wah Pedal

January 20, 2011 by Mike Szczys 9 Comments

Here’s a guitar wah-wah pedal that [Christian Munk] built. Inside you’ll find a circuit board that he etched and populated based on this design but he chose to build the housing out of LEGO. The video after the break gives you an idea of what it sounds like, but for those who’ve stepped on a LEGO piece with bare feet, his pedal pounding might make you cringe!

To manipulate the sound the pedal rocks forward and backward on a center pivot shown above as a grey “nut” sticking out the side of the frame. Inside there’s a system of LEGO gears that turn a trimpot to alter the sound. This might go along nicely with that guitar amp you hacked together.

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Guitar Tube-amp From Junk Hi-fi

January 20, 2011 by Mike Szczys 21 Comments

[Tristan Chambers] picked up an old speaker box some friends acquired at a yard sale. It didn’t have any inputs, and there weren’t any tuning knobs like a radio would have, so it’s a mystery what this was originally used for. [Tristan] traced out the circuit and figured out where he could input audio signals which allowed him to hook up an iPod, but it was mono and not very loud. He ended building his own vacuum tube preamp from a schematic he found on the Internet so that he could use it with an electric guitar. As the video after the break shows, the box not only puts out some pretty good sound but it’s nice and loud too.

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Audio Crossover Back In Service

January 17, 2011 by James Munns 24 Comments

Audio Crossovers are an essential tool for any high end speaker system. Because most individual loudspeakers are unable to cover the entire spectrum of audible sound as well as multiple drivers are, it is necessary to split the input signal into low and high frequency parts. When a friend of [Anthony]’s was about to send off a classic Klipsch AA Crossover to be repaired professionally, [Anthony] insisted it was possible to save some money and do it himself.

The oil can capacitors of the Crossover had gone bad, so a new set of metalized polypropylene capacitors were ordered to pick up the task. After carefully removing the old caps, [Anthony] assembled the new set on a breadboard, and mounted the board to the old Crossover base (along with some tasteful McDonalds straw spacers). The entire process is detailed on his blog, and we are sure his friend saved a good deal by this home repair method. Capacitor issues are a common problem in repairing electronics new and old alike, and always a great place to start looking when devices start acting funny.