Analog Clocks Play Their Own Beat

November 10, 2015 by Mike Szczys 10 Comments

Play the demo video below and try not to let the rhythm worm its way into your brain. What you’re hearing is the sound of a bunch of clocks, amplified. None of them are keeping wall time, but all of them are playing together.

[Gijs] makes crazy musical instruments. He doesn’t give us much more than a video and a couple schematics for this project, so this one’s still a bit of an enigma, but here’s what we’ve put together.

The video looks like eight identical version of the same module. The input takes a voltage and converts the rising and falling edges into pulses to drive the coil of an el-cheapo clock. The LEDs pulse as the poles of the clock switch to the incoming beats. The output comes from an amplified piezo sensor stuck on the back of each clock. That is, what you’re hearing is each clock ticking, but amplified. And if you watch the dials spin, it doesn’t look like any of them are telling time.

So far so good, and it matches up with the schematic. But what’s up with that switch on the front? It doesn’t show up anywhere.

And what’s driving the show? [Gijs] tantalizes us with a master clock module (on the same page) that looks like it does keep time, and outputs subdivisions thereof. But that would be too slow to be what’s used in the video. Has he swapped the crystal to make it run faster? It’s a mystery.

Of course, we’d expect no less from the man who mics up a kitchen timer or a gear motor and adds them to his synthesizer rack. We’ve covered a bunch more of [Gijs]’s work in the past, from his video mixers to this hard-drive turned synth oscillator, but this time he’s got us scratching our heads a bit, as well as tapping our feet.

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Two Turntables And No Microphone

November 9, 2015 by Elliot Williams 23 Comments

It used to be that you had to spend real money to get an alternative controller for your electronic musical arsenal. These days, with cheap microcontrollers and easily-accessible free software libraries, you can do something awesome for pocket change. But that doesn’t mean that you can’t make a sexy, functional piece of art along the way! [Jan Godde] did just that with his cleverly named Wooden Sensor Box With Two Rotary Disks. (If you’ve got a better name for this thing, toss it in the comments.)

From what we can see, the box has two potentiometer sliders, two touch-sensitive potentiometers, two force sensitive resistors, a slew of knobs, and a whole bunch of (capacitive?) touch points. In short, a ton of continuous controllers of all sizes and shapes in an aesthetic case. But stealing the show, and giving the device its name, are two platters from old hard drives that serve as jog wheels.

As shown in the video below the break, the two jog wheels are covered with alternating stripes on the underside. Each platter has a dedicated pair of IR LEDs and photodetectors underneath serving as a quadrature encoder that allows [Jan] to tell which direction the platters are rotating, and how far.

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Synth Secrets Exposed!

November 8, 2015 by Elliot Williams 2 Comments

If you’re at all interested in synthesizers, but haven’t gotten as deep into programming them as you’d like, you absolutely need to check out the old “Synth Secrets” column from Sound on Sound magazine. Across 63(!) articles, the author [Gordon Reid] takes a practical approach to learning synthesizers: trying to copy the sound of one real instrument at a time, with concrete examples built up on one particular synthesizer.

[Gordon]’s approach to synthesis is straightforward, but that’s exactly what makes it useful. After the first couple articles, which introduce you to the common functions of many synthesizers, most articles follow a simple pattern: listen to the instrument’s characteristic sounds, look to the physics behind how it produces them, and then figure out how to replicate as much of the sound as is necessary (or possible) to capture the essence of the instrument. Sometimes when the instrument’s sounds are particularly complex, as in this series of articles on the violin, he’ll break this simple formula up across multiple articles.

Now you might complain that you don’t have a Korg MS-20 or an ARP Odyssey or whatever particular old synth is being used in any particular article. But the “Secrets” are actually so fundamental, and by-and-large worked out on such simple analog synths, that even if you can’t make exactly the same sounds as [Gordon] does, you’ll understand how he got where he got, you’ll probably get pretty close, and you’ll have tuned up your ears along the way.

Plus, you’ll learn a tremendous amount about the character and capabilities of your synthesizer by trying. Working through the “Synth Secrets” examples would be a great way to get to know a new synth in your rack, even if you’re only into space noise and not interested in reproducing real instruments.

But if you are into space noise, also check out our own Logic Noise series. You won’t learn anything about real instruments, but you’ll learn a heck of a lot about the 4000-series logic chips and the abuse thereof.

Thanks [Greg Kennedy] for reminding us of this gem, and for re-installing the “Synth Secrets” bee in our bonnet!

Compressorhead: Best Robot Band Ever?

November 7, 2015 by Elliot Williams 12 Comments

We’ve written about Compressorhead before but we’re writing about them again. Why? Because Compressorhead is the most amazing robot band you’ve ever seen, and because they’ve just opened up a Kickstarter to fund building a lead singer robot and recording an album.

And because they’ve released a bunch of new videos, one of which you’ll find below the break.

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Logic Noise: Digital To Analog With An R-2R DAC

November 5, 2015 by Elliot Williams 28 Comments

Making sound with digital logic usually calls for a Digital to Analog converter. Building one can be very simple, and the sound quality out of an R-2R Ladder is actually pretty good.

In the last edition of Logic Noise, we built up a (relatively) simple VCO — voltage-controlled oscillator — that had roughly one-volt-per-octave response. I even demonstrated it working mostly in tune with another synth’s keyboard. But what if you don’t have a control-voltage keyboard sitting around or you want to combine all of the logic-based circuits that we’ve been building with other circuits under voltage control? That’s where the digital to analog (DAC) voltage converter comes in.

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Controlling Guitar Amps With Servos

October 9, 2015 by Brian Benchoff 27 Comments

[fichl] plays electric guitar, and with that hobby comes an incredible amount of knob twisting and dial turning. This comes at a cost; he can’t change the settings on his small amp without taking his hands off the guitar. While larger, more expensive amps have multiple channels and footswitches, this tiny amp does not. Instead of upgrading, [fichl] came up with a device that turns his single channel amp into a completely programmable one, with just an Arduino and a handful of servos.

The amp in question – an Orange Dark Terror head – has just three knobs on the front of the chassis, volume, shape, and gain. [fichl] had the idea of controlling these knobs electronically, and the simplest solution he came up with is cheap hobby servos. These servos are mounted in an aluminum box, and mount to the knobs with a few shaft couplings.

The footswitch is the brains of the setup, with three buttons, four LEDs, and a DIN-5 output jack that delivers power, ground, and three PWM signals to the servo box. With the help of an Arduino Nano, [fichl] can change any of the knobs independently, or switch between twelve programmed settings. It’s an interesting setup, and something that could serve as a prototype for a much larger system on a much larger amp.

Tape Loop Echo Made With An Actual Tape Loop

October 7, 2015 by Bryan Cockfield 10 Comments

A lot of digital processes are named after an old analog device that they’ve since replaced. It’s not uncommon to “tape” a show nowadays, for example, even though the recording work is actually done by a digital video recorder. Sometimes, though, the old analog devices have a certain je ne sais quoi that is desirable even in today’s digital world. This is certainly the case with [Dima]’s tape loop echo which is actually made with a physical tape loop.

The process of building the tape loop hardware is surprisingly non-technical. By positioning a recording head and a playback head right next to one another, a delay is introduced. An echo is created by mixing the original live sound signal with this delayed signal coming from the tape By varying the speed of the tape or altering several other variables, many different-sounding effects can be achieved.

Although in practice it’s not as simple as it sounds (the device required a lot of trial-and-error), the resulting effect is one that Pink Floyd or Beck would surely be proud of. Analog isn’t the only way to go though, there are plenty of digital effects that are easily created, and some with interesting mounting options as well.

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