I will soon be posting about Audrey II from Synthux Academy. The diagram above is a screenshot from a video explaining the design of Audrey II. It shows a feedback loop that starts with a low noise signal exciting a resonator (comb filter) that produces a Karplus-Strong effect. This is passed successively through distortion, reverb, high pass and low pass filters before being sent through a delay and mixed with the original noise back into the resonator. The output is tapped at the filters, passed through another delay to produce a stereo output

I experimented with stereo patches using this feedback concept, using eurorack modules.

I tried two different noise sources, one from a eurorack random module, the other from my Quantum Ocean (pictured above to the lower right). The noise was patched into either of the Veno-Echo stereo delay or the Make Noise Mimeophon. Veno-Echo was clocked into the Karplus-Strong region and Mimeophon was set to the fastest zone where it can also generate Karplus-Strong.

Output from the Karplus-Strong generator was passed through Instruo Tanh[3] for distortion and limiting, then to the White Rabbit reverb and then through one of the filters available in Vult Freak. The filter output then goes through Nonlinear Memory Machine for delay and mixed back with the noise to complete the feedback input to the K-P generator. I put the Tanh function just after the Quantum Ocean for amplification in some patches.

The filter outputs were also taken to the ThreeTom Doppio, then to the Worng Midside+, with the side signals processed through a channel of NANO modules CEQ before going to the main output.

Four Takes

Improvisation with Mocante/Aurora together with the feedback patch