Jamming on Lightwaves in this Weekend Project

Follow along with Weekend Projects as we build the Infrared String Bass, a 4-string optical guitar. Based on an older build, this project has been updated, replacing the LM741 with the LM386, which sounds great and has the added benefit of only requiring a 9V battery. The circuit is divided into three parts: the main amplifier circuit, and the emitter and detector diode circuits.

Once the circuits are wired up, any interruptions of light between the infrared emitter and detector diodes will generate a corresponding audio signal. In this case, the pluck of a string will convert light into sound!

We start by making a breadboard version of the basic audio circuit. We then multiply this circuit to accommodate four inputs, or strings. Interestingly, the color and material used for the strings produces slightly different sounds. Feel free to experiment with this! Also, feel free to experiment with the look and feel of the guitar. Since the actual body and shape of the guitar don’t effect the output like an acoustic guitar, you can mount this circuit onto whatever chassis you want. Build frets for your guitar, make an upright bass or slide guitar, and design a custom case to put all your hardware in!

Sign up below for the Weekend Projects Newsletter to receive the projects before anybody else does, get tips, see other makers’ builds, and more.

More:
See all of the Weekend Projects posts

7 Responses to Jamming on Lightwaves in this Weekend Project

Zing on July 26th, 2012 at 3:08 pm said:

Actually if your detector has high enough resolution to convert string movement to audio signal with enough fidelity, you will find out that the body material will make a difference. Find out how different woods in a solid body electric bass affects it’s tone.

Reply ↓
JJ on July 30th, 2012 at 12:41 am said:

is there different to commercial systems? http://lightwave-systems.com/

Reply ↓
- Nick Normal on July 30th, 2012 at 5:34 am said:
  
  Why buy it when you can MAKE: it?
  
  Reply ↓
TDev on October 15th, 2012 at 3:47 pm said:

Is there a better amplifier circuit i could use to get a better sound?

Reply ↓
- Nick Normal on October 16th, 2012 at 1:05 pm said:
  
  hi TDev, the LM386 was employed because it only requires one 9V battery. I’m curious what type of sound you’re currently getting, and what you don’t like about it?
  
  Reply ↓
  
  TDev on October 16th, 2012 at 3:08 pm said:
  
  Hey Nick, I havent actually built it yet and im researching a number of projects but i was just wondering if anyone went further with this and what results they got, for my project it would need to be a bit more advanced circuitry wise.
  
  Reply ↓
Beats By Dr Dre Pro Diamond on April 29th, 2013 at 7:45 am said:

Beats reportedly named the project “Daisy” honoring what it called the primary digital, computerized song. At the time, it said in a news release that the service would likely “bring an emotional connection time for the act of tunes discovery, ” referring to the method through which users come across, buy and consume songs.

Reply ↓