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.

Wednesday, April 8, 2015

Valve WizardEntropy Chorus

Stumbled across this effect while looking for a completely different schematic. It's a low cost chorus designed by Merlin Blencowe (here's his schematic for reference), using a PT2399. It generates deep modulation and a very thick warble (here's a sound clip).


  1. construi um tambem e nao funciona
    ainda nao descobri o porque

  2. 2 times tried,but I only got echo and pots didn't worked well, so I built little Angel one. Perfect!! Layout is not the problem in my opinion, it's more a matter of using some configuration with our friends 2399s XD

  3. Quickly built the PCB version this afternoon. Didn't work. The rate oscillator that uses pin 13 & 14 was not running. There is a layout error. There is a link on the board that goes to pin 14. Remove this link and use a jumper wire from the pin 14 hole of the link just removed and run the other end of the jumper wire to the junction of the 91K and 10K resistor. The oscillator will now run and the board now matches the Valve Wizard circuit.

  4. almost PT2399's pedal.. The pin3 and pin4 is connected, like in LAChorus, DBDelay, also Equinox Reverb.. i verified 3 of em
    So give it a try, connect the pin3 and pin4..

  5. I use it with an active jazz bass, I changed the controls in half 50k and 5k. the 47n capacitor from pin 2 of depth by one of 150n, and the input capacitor of 100n by one jump.
    the problem I notice is that with a passive guitar it makes a tremolo effect.
    lo uso con un bajo jazz bass activo, cambié los controles por la mitad de valor 50k y 5k. el capacitor de 47n del pin 2 de profundida por uno de 150n, y el capacitor de entradade 100n por un salto.
    el problema que noto es que con una guitarra pasiva hace efecto de tremolo

  6. I confirm that the fix mentioned by Slowpoke101 works. Just use a longer jumper. Also, the depth knob is backwards. I'll try to make a video of the effect once I put it inside an enclosure.