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Detailed schematics for it are still available online, but unfortunately one of the ICs is obsolete and difficult to obtain.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!

PAiA-Chord-EGGv002.pd

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

I've recently been thinking about using a Turing machine type module in Pure Data to add sequencers. Some of the Eurorack designs look pretty cool but, I'm not finding a lot of info on versions of these in pd. Any good examples or tips to design one?

@jameslo @seb-harmonik-ar

Thanks! The toggle patch works like a charm!! This will save years of my life!

I'll just make a copy and send a message to the toggle objects to clear the receive of one and the send of the other.

@jameslo That sounds interesting! How do you set up the clone architecture?

I'm a beginner currently working on a 24/24 Toggle matrix to use as a general purpose tool for patching.
The Toggles are organized in a square grid inspired by a design used by a few vintage synths to connect modules together. The toggles basically function as ON/OFF switches for patching signals in a synthesizer.

For example, if the output of a sine wave oscillator is sent to horizontal row ( 4 ) and the input of a filter is connected to vertical row ( e ) they can be connected together by triggering the toggle e4.

By sending (send) or (receive) messages in a message box I was able to give several toggles the same row name. I started manually numbering these but then realized that I’d have to name 1152 of them! Half of them sending and the other half receiving with different letter and number combinations.

Is there a way to give the toggles a two part message that includes the numerical row and the alphabetical row so I don’t have to manually add a number?
Or do some kind of row check similar to a button matrix?

Patch Matrix 1.pd