This is a library of perfboard and single-sided PCB effect layouts for guitar and bass. I'm not an electrical engineer by any stretch of the imagination, just a DIY'er who likes drawing layouts. It is meant for the hobbyist (so commercial use of any of these layout is not allowed without permission) and as a way to give back to the online DIY community.

Tuesday, August 14, 2018

Valve Wizard Jenny Greenteeth

Here's a weird chorus from Valve Wizard based around a PT2399. In Merlin's own words...

Chorus is created by passing the signal through a very short delay line, somewhere between about 8ms and 25ms. The delay time is modulated and the delayed signal is mixed back with the original un-delayed signal. Some feedback ('repeats') is often applied too, to thicken the effect. The PT2399 has a minimum delay time of about 25ms, which is just short enough to do a thick chorus effect. The more subtle chorus effects that a 'proper' chorus pedal would do are not available as they require shorter delay times ( but I'm one of those people who only ever wants his chorus thick!). However, as well as getting chorus I soon found that various other unexpected effects could also be had for free, including pitch bend and a kind of ring modulation. That's why I've called it 'weird chorus'.

It will fit in a 125B with top mounted jacks easily, but it's narrow enough that it will fit in a 1590B, but probably without the pots board mounted. Here's the original build doc with the schematic and Merlin's original layout.




13 comments:

  1. what can i sub the bc337 with?

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    1. They are a whopping .05 cents on Tayda. Why bother substituting?

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  2. https://alltransistors.com/crsearch.php?mat=Si&struct=pnp&pc=0.36&ucb=50V&uce=45V&ueb=5V&ic=0.8&tj=150

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    1. YO HE VARIADO POR UN BC548 Y UN 2N4401,,FUNCIONA MUY BIEN,,TAMBIEN 202 EN VEZ DE 222

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  3. Hello, I like this one, it reminds me of the Danelectro FAB Chorus but with no mix pot, I would like to have a more useful sweep range for depth pot, should I try bigger or smaller values?

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  4. Hi! Maybe I'm wrong but I think there is a little mistake with this layout.Resistor 47k and diode 4148 must be connected to +5v ,not to ground.Resistor in series with rate pot is 4,7k not 47k.

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    1. Can confirm these fixes make the pedal work "as it should."

      Haha this is a weird one and I love it, and I'm pretty sure it doesn't do anything that "it should."

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  5. Dobrin, it work for you with that corrections? Mine not yet.

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  6. Verificado, tal como esta, recomiendo usar zocalos en transistores y capacitores para variar, experimentar con otros valores.

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