Neptune Delay – DIY PT2399 Echo with Modulation

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Neptune Delay

The Neptune Delay is a PT2399-based digital delay with footswitch-controlled modulation. The base/core circuit was derived from the Sea Urchin circuit drawn up by (no longer in production). The Neptune differs from its predecessor in a few key ways, however: the delay line filtering has a much lower cutoff frequency (high pass filtering), leading to very smooth and murky repeats that are virtually free of the digital noise that often plagues PT2399 delay circuits; and it also has a momentary footswitch that modulates the delay time in very interesting ways.

Download the Neptune Delay File Pack.
Includes: Schematic and PCB Layout images, legacy build guide, and Eagle CAD files.

Here is a very old and very crappy demo video of the Neptune Delay: