Category: Project

12/22/16 – The LED Panner is another fun circuit from the great book “Handmade Electronic Music” by Nicolas Collins.

This circuit uses a single 74C14 Hex Schmitt Trigger chip, taking advantage of only a few pins (so you could to much more with this). LEDs paired with photo resistors create an optically controlled circuit which is designed to switch audio off and on in a flip-flop or ping-pong type motion. A single dial adjusts the speed of the effect. You can use just one side of the device for a mono signal, or in stereo, though stereo is where you get the neatest effects.

I always seem to do the most building during the holiday season, hence the Christmas themed box. The initial breadboard prototype went together rather quickly, so it wasn’t long before I had everything in the box. The hardest part was deciding on a physical layout for the LED/photoresistors, as they take up a lot of space. I would probably try a different orientation if I built one of these again, but this works fine.

The unit below with the green knob is the same unit as the one with the red knob. Only difference is that at first I didn’t add an on/off switch. That was added later and I changed the knob because I thought it matched the case better.

I built this device as an addition to my constantly evolving electronic/experimental music soundscape table, which you can hear on my Soundcloud page. Recordings featuring this device coming soon.

12/9/16 – The Xmas Fly is a riff on the Black Fly, which is basically nothing more than a piezo element and a few parts in a nice box. The Black Fly includes springs, which cause interesting vibrations for the piezo to pick up.

To make springs work you need a very solid box that can hold up to the hardware. I didn’t have such a box, so I used one of my Christmas tins and made this into more of an ambient pickup rather than a device that created it’s own sound. Youtube shows several hacks for the Black Fly, so all I needed was an interior photo of the build from one of those videos, and the rest was easy.

The piezo is set in place with Guerrilla Glue. The filter capacitor value was a bit tricky. First attempt with a 10pF cap showed no filtering effect. I couldn’t make out what they were using in the photo, so I checked with my dad who advised based on his experience with similar circuits, “try .01uF to .05uF. The pot could be 50K more or less… ” The second attempt with a .022uF Mylar cap works well!

What’s it for? This can be used as a pickup for all sorts of sounds around the studio, basically like a low-fi mic. The filter acts as a tone control, which is necessary to roll off some of the harshness of the piezo. Paired with a proper DI box, this can be a very effective tool for sound design. The larger form factor and thinner metal also gives this much different properties from a Black Fly, though I would still like to build one of those when I have the materials.

To hear this in action, check out some of my piezo sound scapes.