Projects => Build Reports => Topic started by: culturejam on March 31, 2021, 01:46:50 PM

Title: Modulated Echo - Spatial Edition
Post by: culturejam on March 31, 2021, 01:46:50 PM
I'll be releasing this as a DIY project at some point in the near future, but wanted to post the first build now since I liked how (almost) everything turned out. Sound clips are in the works.

The base delay circuit is one that I and earthtonesaudio (of DIYstomboxes fame) came up with several years ago, and as I recall, it was the inspiration for madbean's Cave Dweller project. I had initially intended the original as a pseudo-reverb type of effect (short delay time and loads of feedback), but it also works out pretty well as a longer delay. Then recently I was playing around with a CD40106 oscillator and working on getting the wave shape to resemble something usable for modulation effects (triangle shape, at least), and I wondered how it would work with a PT2399 to wiggle the delay time. I still need to hook it up to my scope and have a look, but it seems to get pretty close to a triangle, if not a little bit more like a sawtooth.

To cut to the chase, it works pretty well with a PT2399, so I boxed it all up. I did the LFO as an on-the-fly perf layout, and I'm quite pleased with how that turned out. PCB for the delay was one already populated that has been kicking around my work bench for years now. I'll be doing a new integrated PCB that puts everything together. Still have a few minor things to work out, but the circuit is 95% done. More details to come!

The Depth and Time controls are highly interactive because of how it's set up. It's odd, but also offers a lot of flexibility on the tone of the repeats because as the Time control is increased, there is more and more low-pass filtering of the delay line. So you can turner that back a bit and then crank the Depth and get longer, clearer repeats. Or you do the opposite and get darker, more  BBD-like filtered repeats. Modulation ranges from mild to borderline insane.

The enclosure is etched with my little hobby laser (5w) and then backfilled with acrylic paint. I found the graphic on a stock image site and thought it would be cool on a pedal. I did white on the top, and white and gold on the bottom plate. Gold looks pretty solid on a blue box.

Definitely had to compromise on control layout because of using a PCB not designed for this kind of application. Perf LFO uses board-mounted pots for stability. Miscalculated the drill spot for the DC jack (classic culturejam!), so that's fugly. But this is a true prototype sort of build, so I don't mind.



Title: Re: Modulated Echo - Spatial Edition
Post by: jimilee on March 31, 2021, 02:25:09 PM
Nice job Forest. Looking forward to some tasty delay.

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Title: Re: Modulated Echo - Spatial Edition
Post by: matmosphere on March 31, 2021, 03:09:03 PM
Very cool, canít wait to hear what it sounds like.
Title: Re: Modulated Echo - Spatial Edition
Post by: jjjimi84 on March 31, 2021, 05:17:48 PM
Super cool! I cant wait to hear it.
Title: Re: Modulated Echo - Spatial Edition
Post by: Bio77 on April 01, 2021, 05:26:44 PM
That graphic is super cool!  Interested to hear it.