Loop Machine

Did you ever spend time circling a great idea without realizing it? The moment of recognition is an epiphany that can make one feel a genius. Or make one wonder what great ideas one never recognized.


A few years ago, a little transistor radio-sized device called the Buddha Machine caused a bit of a stir. Created by a duo of Chinese musicians who go by the name FM3, the small plastic box plays ambient music loops. The only controls are the volume knob (with integrated power switch) and track switch (a sliding switch). A newer version changes track control to a button and adds a playback speed control.

FM3 based the Buddha Machine on chanting boxes found in Asia, which are meant to be a sort of portable temple for Buddhist and Hindu faithful. There is an amazing variety of the small plastic boxes – different sizes, colors, number of tracks, and religions.

Inspired by the Buddha Machine, industrial music pioneers Throbbing Gristle worked with FM3 to create the Gristleism, a looping box that plays jarring sounds meant to annoy rather than soothe.

Several weeks ago, it occurred to me that with an Arduino, it should be possible to make a looping box with custom sounds. It seemed a good project for Handmade Music L.A., which is taking place at Crash Space later this month.

I’ve been calling it Loop Machine.

The challenge was choosing an Arduino shield to play back audio. The Arduino itself is not capable of playing back full bandwidth audio, but Adafruit has a Wave Shield which seems perfect. It plays WAVE files stored on a SD card, which makes the device easily updatable. A volume thumbwheel with integrated on/off switch works just like the chanting boxes. There is a headphone jack, but I will probably hook up a small speaker (recovered from a dead portable DVD player) to the jack. A 9 volt battery can provide power.

The only addition is a button to to switch tracks, which is simple to do with an Arduino.

One of the Crash Space members works in a cigar shop and he brought in a bunch of cigar boxes, one of which was a perfect size for the Arduino and Wave Shield.

The hardest part of making the box work was figuring out the WaveHC library that controls audio playback. The library documentation is complete, but lacking a certain practical aspect, which is common for programming libraries, but still very frustrating.


While developing the prototype, I used a couple simple audio sketches that I had made for other purposes. I needed more than a couple, so the next step was to make more loops. Ideally, the loops should go well together. And not necessarily sound like loops (mostly meaning longer than a few seconds).

That’s when I noticed the great idea. The collection of loops would be the next Bangsplat album. The loops could be listened to linearly (on a CD or a folder of MP3 files), but the full version would be loaded into a Loop Machine and listened to in that manner.

The Arduino and Wave Shield are open source, and the schematics and design files are available online. I will make the Arduino code available once I fully debug it and clean it up, along with implementation details (what pins to hook up to what, and how to build it into an enclosure).

I will also sell pre-built Loop Machines. I will not be cheap, but the option will be there for anyone who wants one, but does not want to build their own.


  1. Ian
    Posted 12 July 2011 at 10:26 pm | Permalink

    Were the Loop Machines ever created, or did you post the schematics/design files? I’m not the most tech savy, but I’d love to try.

  2. Ian
    Posted 12 July 2011 at 10:27 pm | Permalink


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