A CMOS version of the Nyquist aliaser

The Nyquist aliaser is a strange sounding effect which sometimes resembles a ring modulator. Works by "sampling" the signal at a frequency set by a pot, in the same way it happens in an analog-to-digital converter. But unlike the converter, the frequency is set into the audio range, so all kind of aliasing artifacts appear in the final sound. It can make your guitar sound like some kind of synthesizer, and/or heavily distorted.

This version uses only two CD4016 CMOS switches to buffer, amplify, sample the sound and provide the clock. It has very low bleedthrough (as long as you keep your wiring neat and use a good layout, like the one made by Basicaudio). It was presented for the first FX-X competition at Aron's Stompbox Forum, but only came on second place :(.

Listen for yourself:

Here's the schematic: Click on the image to enlarge

Fellow stompboxer Basicaudio made a PCB layout, which is already tested to work OK. Download it here.

Related stuff

Read this articles to expand on this subject:
JC Maillet's Nyquist aliaser, schematic and theory of operation.
Sound samples and some talk about the effect at Aron's stompbox forum.

v1.0 07/05/2007

Miguel Canel, Buenos Aires, Argentina bioroids.miguelNOSPAM@yahoo.com.ar (Quitar NOSPAM) http://www.bioroids.com.ar