Turning A Broken Bass Into A Headless Bass

January 11, 2013 by Brian Benchoff 5 Comments

bass

A while back [Michael] inherited a broken bass guitar from a friend. The headstock for this bass was cracked right down the middle, and the friend attempted a repair with a bolt and a couple of washers. After trying to figure out what the addition of a bolt was trying to accomplish, [Michael] set to work repairing this bass and ended up doing a headless conversion.

A headless bass, just as the name implies, does away with the headstock and moves the tuners to the other side of the guitar – in [Michael]’s case, right below the bridge. After sawing off the broken headstock above the truss rod, [Michael] made a string retainer and bolted it on to the remainder of the neck.

The tuners had to be moved, of course, so [Michael] routed out a section of the body below the bridge. Four holes were drilled and the original tuners slipped right in. The result is a perfectly functional bass that would fit right in to the tour van of an 80’s metal band.

You can check out [Michael]’s bass down in the pocket.

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Reading Piano Rolls Without A Player Piano

January 7, 2013 by Brian Benchoff 22 Comments

detection-example

A while back, [Jacob] played around with a player piano. After feeding a roll into the machine and trying to figure out how a fifty year old machine using hundred year old technology can replicate a skilled pianist, he decided to take a crack at decoding piano rolls for himself. He came up with a clever way of doing it over Christmas break, using a camera and a few bits of OpenCV.

The old-school mechanics of a player piano use a bellows and valve system to suck air through dozens of holes, making the action hit a string whenever a hole is present in the piano roll. To bring this mechanism into the modern age, [Jacob] pointed a video camera at the active part of the piano roll and used OpenCV to translate holes in a piece of paper to a MIDI file.

The synthesized version sounds just as good as the original paper scroll-based version, as seen in the video after the break. There are a few sync issues in the video and the resulting MIDI file isn’t in the right key, but that’s easily fixed by anyone willing to replicate this project.

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Put That Headphone Jack Anywhere You Want It

December 25, 2012 by Mike Szczys 17 Comments

yamaha-keyboard-headphone-jack-hack

Check out this brand new Yamaha keyboard. The fact that we’re seeing the guts means that [Todd Harrison] can kiss his warranty goodbye. But by now you should know that he doesn’t look to others when something goes wrong with his electronics. This time around he’s not repairing anything. He didn’t like having to plug in headphones on the rear of the keyboard. He cracked it open and relocated the headphone jack to a more convenient location.

As you can see, there’s a ton of room inside once the MDF base which holds the speakers and some sounding boxes has been removed. While he’s in there he takes a good look at the mechanics of the keys. They’re weighted with metal rods (seen above) to help the electronic instrument feel more like an acoustic version to the player. But he doesn’t neglect the chance to gawk at all the electronics as well.

After pulling out the PCB that has the headphone jack on it he goes to work with a solder sucker. With the solder gone he cuts through the glue that holds the jack on the board. All that’s left is to solder some wire in its place and give it a nice project box as an enclosure. To complete the hack he mounts the box on the MDF base and now the headphones connect on the front. See the entire process in the video after the break.

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Organ Pedals Fill In When Your Bass Player Is Missing

December 18, 2012 by Mike Szczys 10 Comments

organ-foot-pedals-instead-of-string-bass

Since his string bass player isn’t always around [Antoine] built his own electric bass stand-in using the pedals from an old organ. The project — which he calls the Organ Donor — was inspired by a similar standalone organ pedal bass project. That instrument was built using a 555 timer to generate the sound. But [Antoine] has a little more room for growth as he’s using an old microcontroller development board to generate sound.

The octaves worth of pedals were pulled from an old broken Yamaha A55 Electone organ. After extracting the assembly from the instrument he built a nice wooden case around it. This doubles as a stand for the amplifier which broadcasts the sound. An old Freescale development board is wired up to twelve of the keys (the top C is unused). It generates a square wave at the appropriate frequency for each key. This signal is fed through a low-pass filter before being routed to the audio jack on the back of the case.

Future improvements include building an amplifier into the pedal assembly. We would also love to see different signal processing to expand the range of sounds the pedals can generate. We’re not sure of the capabilities of that microcontroller, but it would be neat to hear tone generation using stored samples.

Tablet Rig Takes Sheet Music Digital

December 12, 2012 by Mike Szczys 12 Comments

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[Bill Dudley’s] wife wanted to use a couple of different tablets for displaying sheet music. Sure, a proper music stand will have no trouble supporting the weight of the device, but if it’s not secured it place you may soon have a broken device. [Bill’s] solution was to build this tablet stand out of PVC.

The image above doesn’t tell the entire story of how he did this. But if you look really closely you’ll notice that the pipe is actually acting as a frame rather than a cradle. After measuring, cutting, and gluing all of the components together he cut a channel around the inside of the u-shaped PVC frame. The channel is the exact thickness of the tablet and holds the device securely. A base from a music stand makes up the rest of the rig.

Pages can be turned using a USB foot pedal. This is fantastic for gigging musician who use digital music collections like the Real Book.

Digital IR Theremin

December 12, 2012 by Eric Evenchick 6 Comments

This Digital IR Theremin creates tones based on the distance of an object from its IR sensor. There’s no microcontroller here, since the project is part of an Introduction to Digital Electronics course. Instead, it uses a handful of comparators, transistors, AND gates, and a 555 timer to make noise.

The comparators are connected to create window comparators. This configuration will output a digital 1 if the input is between two reference voltages, and 0 if it is not. Using this, the analog output of the IR range sensor can be converted to digital values.

The 555 timer takes care of creating the output waveform. A specific resistor is switched in to the timer’s RC circuit depending on which window comparator is active. This allows for a different tone to be played depending on the distance from the IR sensor.

The result is a square wave, which has a frequency dependant on how close an object is to the IR sensor. By selecting the right resistances for each distance, the theremin can be tuned to play a specific scale.

This is a neat project for people looking to learn digital electronics, and the write up does a great job of explaining the theory. After the break, check out a video of the theremin generating some tones.

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Air Harp Using The Leap Motion

December 5, 2012 by Mike Szczys 6 Comments

leap-motion-air-harp

He’s just pointing in this image, but this Air Harp can be played using many fingers as once. It’s a demonstration which [Adam Somers] threw together in one weekend when working with the Leap Motion developer board. We first heard about this slick piece of hardware back in May and from the looks of it this is every bit as amazing as first reported.

Part of what made the project come together so quickly is that [Adam] had already developed a package called muskit. It’s a C++ toolkit for making music applications. It puts the framework in place what we hear in the video after the break. The weekend of hacking makes use of the positional data from the Leap Motion and handles how your digits interact with the virtual strings. You can watch as [Adam] adds more and more strings to the virtual instrument for his finger to interact with. The distance from the screen is what decided is your finger will pluck or not. This is indicated with a red circle when your fingertip is close enough to interact with the phantom string.

Get your hands on the code from his repositories.

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