[Dino’s] JFET Guitar Preamp With Piezo Pickup

September 12, 2011 by Mike Szczys 10 Comments

This week, with a little help from a Roomba, [Dino] built a guitar pickup and preamp that sounds marvelous. A pickup takes vibrations from the guitar and turns them into an electrical signal which can then be amplified and broadcast. He grabbed a long-dead Roomba which has slowly but surely been donating its organs for his weekly projects. After plucking out a piezo element he grabbed a bag of Junction gate Field-Effect Transistors (JFET) and built a preamp circuit around one of them.

JFETs operate in much the same way as MOSFETs (which we took a look at last week). [Dino’s] design adds a few resistors and capacitors to tune the gain and decouple the circuit from the input and power rails. He epoxied the piezo element inside the guitar and connected leads between it and a jack mounted in the body. As always, he does an excellent job of explaining the concepts behind the design and outlining the build techniques that he used. We’ve embedded his video after the break.

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Broken Vintage Record Player Reborn As A Portable MP3 Cabinet

September 7, 2011 by Mike Nathan 23 Comments

old_record_player_pc_jukebox

[Julian] picked up an old record player that was sitting in somebody’s trash pile, and brought it home to see if it could be restored to working order. When he got it home he discovered that it didn’t work at all, so he and his wife decided to modernize it a bit.

In an effort to simultaneously reunite himself with his music collection and piss off audiophiles/antique collectors in the process, he gutted the radio and began rebuilding it to serve as an MP3 jukebox. Once the innards were removed, his wife refinished the cabinet and gave the front grill a new cloth cover.

An old PC was installed inside the cabinet, along with a set of relatively cheap (but better than paper cone) speakers. A pair of custom cut plexi panels were used to cover the computer, while providing space for the monitor and Apple wireless keyboard + trackpad [Julian] uses to manage the jukebox.

The refurbed record player came out looking quite nice, and although it likely raises the ire of several different groups of purists, we think it’s pretty cool.

Controlling Samplers And Sequencers With Multitouch

September 6, 2011 by Brian Benchoff 5 Comments

When we see artists like Daft Punk or Madeon working their magic in a live setting, we’re always impressed with their controllers. Sample-based artist use controllers like the Monome and Kaoss Pad a lot, but these devices are fairly expensive. Thankfully, we live in an age of multitouch displays, so [Graham Comerford] came up with his own multitouch controller that does just about anything.

The build is based on the Kivy framework and includes a Monome emulator, MIDI drum pads, mixer, and a whole bunch of other sliders and buttons. There’s no word on how [Graham]’s multitouch display was constructed, but if you’re looking to build your own gigantic audio control setup there’s a lot of info on building Microsoft Surface clones, adapting computer monitors, and spherical multitouch rigs.

We’re not sure if [Graham]’s virtual drum kit is velocity sensitive but even if it’s not, it’s an interesting bit of kit. Check out an earlier version of his setup after the break.

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Insects Turned Into Orchestra; Not Harmed But Terribly Inconvenienced

August 31, 2011 by Brian Benchoff 28 Comments

[Jochem] has always been fascinated by chaos in nature, whether it’s a swarm of ants or evolution in action in a petri dish. His insect orchestra takes the chaos in the natural world and changes it into something completely artificial. In this case, MIDI.

For the build, a light sensor was placed at the bottom of a test tube. A cricket (or grasshopper, or locust) is then put into the test tube. The test tube is then closed up with a cap that houses a LED. An Arduino reads the light sensors and then transmits the data over MIDI. The MIDI commands are picked up in Abelton Live which converts everything to audio.

[Jochem] rigged up Abelton to have the insects perform in four different modes – instrument, synthesis, samples, and drums. Definitely an improvement over the humble Mexican Jumping bean.

You can check out the insect orchestra in action after the break.

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Guitar Pickup Winding Workstation

August 30, 2011 by Brian Benchoff 16 Comments

After a bit of inspiration, [Pete] decided to build a solid body electric guitar for himself. Instead of assembling a conglomeration of off-the-shelf parts, he plans on building just about everything from scratch. This includes the guitar pickups, so he built himself a pickup winder that has measures RPM, ETA until done, and auto stop for when the pickup is complete.

Electric guitar pickups are simple devices – just a magnet for each string wrapped in thousands of turns of wire about as thin as a human hair. [Pete] began his build with a cheap sewing machine and added a tachometer and pickup mount. As an added bonus, [Pete] threw in an ohmmeter to measure the coil resistance and a Gauss meter to measure the magnetic flux and polarity of the pole pieces. It’s a very nice build that’s designed to be as functional as commercial pickup winders.

[Pete] was originally inspired to build a pickup winder by the Les Paul Google doodle, and he plans on continuing Les Paul’s tradition of guitar innovation by building his own solid body guitar. The wood has been cut already, and we can’t wait to see the final product.

Check out a video of [Pete]’s coil winder in action after the break.

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High Voltage Hacks: A 1000 Watt Tube Amp

August 26, 2011 by Brian Benchoff 26 Comments

Normally when we hear of a Champ guitar amp, we think of a sweet-sounding rig that puts out 6 Watts through an 8-inch speaker. [John Chambers] of Champ Electronics wanted to build a true champion for the field of battle and came up with The Champ 1000 Watt Tube Amp, an amplifier that probably puts out enough heat to keep an igloo warm.

The amp is based on 807 valves. With some clever engineering [John] managed to coax 100 watts out of a pair of 807s, so the entire amp “only” requires 20 power tubes. The build log shows some pretty impressive examples of electrical prowess. We can’t recall the last time we featured a build with point-to-point wiring on tagboard, and [John]’s work is some of the best we’ve ever seen.

[John] has been working on this amp off and on for a few years now, but he should be wrapping up the build sometime soon. We haven’t seen this amp in action, but we imagine it would look something like this 36×10 monstrosity. Send us a message or post a comment if you can find a video and we’ll put it up.

Water-powered Multi-channel Audio

August 24, 2011 by Mike Szczys 8 Comments

[Niklas Roy] is rolling out some water-powered music for Berlin’s Museum night. It seems that this water-wheel is attached to the side of the Museum. It’s got a stream flowing past it and the wheel is constantly turning. The thing is, that work isn’t being used for anything. Now we’ve already seen [Niklas] making electricity from moving water, but that’s far from what he had in mind this time around. Instead he’s driving a multitude of music boxes with the motion transferred from the water.

He teamed up with another artist named [La belle Imira] to build and connect a series of pulleys to the waterwheel. The video after the break shows the rope system being strung throughout the grounds of the museum. After passing around the output drum of the water wheel, the rope snakes through each pulley. Many of the pulleys have the mechanism from a music box attached to their axles, so whenever the water is flowing, music plays. They don’t all play the same tune, so you get a variety of selections as you walk around. We could swear that one of them is playing ‘My Way’.

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