The PAiA Chord EGG creates an endless stream of majestic tones.
As soon as you turn it on, it instantly sends the listener on a trip to the underground oceans of the Europa.
The circuit was made by the American synthesizer company PAiA in 1978, and was distributed in electronics magazines for DIY builders.
Detailed schematics for it are still available online, but unfortunately one of the ICs is obsolete and difficult to obtain.
After studying the schematics and listening to recordings of it, I decided to make a version in PD.
The Chord EGG randomly selects between four chords. Importantly, each note in a chord is faded in and out by a random slope generator, which I made by filtering a sample & hold source. The complete output is then made stereo by a pair of bandpass filters, which also have a random slope controlling cutoff.
No abstractions are needed, but it can be used as an abstraction within other patches in addition to a stand alone patch.
Enjoy!
All credit for the original circuit design goes to PAiA, John S. Simonton, Jr. and Craig Anderson.IMG_2287.jpgchord-egg-low-res.jpgPAiA-Chord-EGGv002.pd