Nurse Quacky almost there :D

[thomas2]

well i decided to try building it again.. this time there's sound! well sorta.. there's only this low rumble going on.. no highs at all.. how are the two led's supposed to work? mine has the other led on all the time (the one connected to pins 3 and 4) and the other one doesn't do anything at all..    any kind of information about this would be appreciated.

[Sic]

what layout are you using? the home-wrecker one?

[thomas2]

yep

[thomas2]

i mean.. yes, the home wrecker one  :lol:

[B Tremblay]

The LED between pins 3 and 4 should be always lit when the circuit is powered on.  The other LED should light in relation to the input signal envelope.

Double-check the wiring of all three pots as well as the orientation of the LED connected to the 3M3 resistor.

[thomas2]

thanks! i'll check that tomorrow.. well i didn't have the 3M3 resistor.. i substituted it with two smaller ones..

[B Tremblay]

well i didn't have the 3M3 resistor.. i substituted it with two smaller ones..

Double-check that those values do in fact add up to 3M3.  If that resistor is too small, the LED will not light in the same manner.

[thomas2]

alrighty then! i noticed that it works when i hit the strings very hard. i tried it with a booster pedal and it worked! i dunno where the problem is..
well anyway.. does anyone know how i would get more attack?

[thomas2]

actually what i'd like to know is.. how can i get a faster decay.. i'd like it to make the wah sound quickly with every note.

[B Tremblay]

Change the 22uF cap (to ground after the 51 ohm resistor) to a 10uF for faster decay.

[thomas2]

thank you sir! i'll do that  :lol:

[smoguzbenjamin]

If it works with you booster and when you hit the strings hard, I think you don't have enough gain in the envelope detector. Try increasing the resistance in the opamp's feedback loop as to increase the gain.

[idlefaction]

also, the half wave diode sucks the first 0.7V out of the envelope detector signal - i take out the 'pin 3 & 4 LED' and replace it with the same LED in series with a regular diode, that gets rid of that problem and makes the envelope detector 0.7V more sensitive without even having to change the 3M3 resitor.  :-)

PS. building a treble booster into the effect will also work!  these filters work best like that anyway since your high strings put out less voltage than your low strings. HTH...

[idlefaction]

oh yeah!  if you replace the 10k resistor that's in series with the LED/diode i was just talking about with a 10k pot, wire the ends of the pot to 9V and the LED, and connect the input pin of the envelope opamp to the wiper, you have an instant manual filter control - great for set wah effects if you turn the sensitivity right off, or just adjusting the envelope start point to taste.

[thomas2]

thanks! any mods how to make the effect more extreme?  :twisted:

[Torchy]

Before I dig out ExpressPCB, anyone got a pcb layout for the Quack ??
Ta  :wink:

[Gringo]

I drew one just for fun the other day, let me take a look cos i don't remember if it's finished.

[thomas2]

i've done it too, but i believe there was some small error.. gotta check that
:lol:  it was way easier and faster to build on perfboard than pcb

[thomas2]

this is what mine looks like.. compare it to the home wrecker layout and see where everything goes  :lol:

[thomas2]

fixed the error btw  :wink: