Glitch LFO

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Glitch LFO

I’ve been wanting to get into circuit bending for a while now, but due to a jam-packed project notebook, it has taken the back seat…until now.

Music is my passion. I’ve played various instruments throughout my life and have always loved strange and exciting sounds and instruments. That being said, I’ve decided to focus my attention on music-making instruments / bends / circuits for a while. There’s something euphoric about mixing my love for music with my love for electronics…it’s hard to explain.

Seeing as I’m still a n00b at bending, I thought it proper to start with a staple bent instrument and see what I can do…enter garage sale find #1: Casio SK-1. As I started scouring the internet for ideas of bend points, and various different things people have done with the SK-1, I came across this really handy LFO circuit based on a LM555. I had all of the components in my parts bin, so I built it and started playing. The circuit itself is nice, but when applying it to any bend points, there was something missing. One of the changes I tried out was applying a PNP transistor to the trigger, so it acts as a switch that is being turned on and off to the speed of the timer. When I applied the bend points to either end of this switch, the results were very satisfying. I decided that for my bent SK-1 it would only be right to etch a PCB, so I made a quick change to the etch template and wanted to share that with everyone. I’ve also attached a few pics and a video of me playing with my SK-1 with this “glitch LFO”. I hope someone else gets some use out of it!

Download etchable circuit drawing here.

Comments ( 3 )

  1. ReplyArni Geir Larusson
    Hey!! This sounds really nice!! I would really like to build one of these. I was just wandering what tipe of NPN transistor you used? Cheers and keep up the good work!!!! :D Arni Geir
  2. ReplyDan
    Thanks Arni, I believe the transistor I used is a 2N5058. I'm close to having this project done, and will post more details when it's complete.
  3. ReplyPerry
    Hey, I just wanted to know if any general purpose NPN Transistor would work in the LFO. Thanks!