Here’s a wonderful effect that can be used with a guitar (listen to the sample at the bottom) or just any instrument. I don’t think it can be done with any existing stompbox, analog or digital (please correct me if i’m wrong!).
This patch was made by Katja, who shared it on the Pd forum (her post is here, and I use here patch in my blog with her kind permission). Katja’s been very active in the Pd community lately, and if you’re not a beginner you should take a look at her website (there are lots of interesting things, including patches and externals).
You can get awesome sounds with this patch. If you toy with the sliders as you play (or if you control them with LFOs or with Arduino) you can get sounds close to the famous guitar solo in Talking head’s “Born under punches”.
As in the majority of effects altering the pitch of the incoming sound, this patch is based on a delay line. The trick here is that the length of the delay line follows a “trapezoidal” curve, as described in the figure below.
Here’s the original patch. Please note that she changed the default appearance settings of the sliders (read this post if you want some tips to use the GUI efficiently). Also, note that the two messages in the lower right corner reading “pd dsp 1;” and “pd dsp 0;” are there to turn the audio on and off in Pd. This is very useful if you want to automatically turn on the audio when you open a patch.
- Here’s the link to download Katja’s patch.
- And a sound sample 🙂