"Peak" LED circuit?

[teej212]

Im trying to make a pedal have an LED indicator that would brighten when the input signal increases. So when i strum softly, the LED would be dark or slightly bright, and when i strum or pick hard, the LED brightens with the intensity of my playing. any one know of a circuit that does this?

i tried this one, but it doesnt seem to work with guitars

[Earthscum]

That's because you have to use a signal that will overcome the diode's forward voltage drop, in this case about .6-.8V, I'm guessing.

[Hides-His-Eyes]

try sticking an op-amp booster in front of it.

[Processaurus]

The envelope detector part of the "Nurse Quacky" envelope filter does that -brightens an LED based on how hard you pick.

[deadastronaut]

maybe this.....

http://www.diystompboxes.com/smfforum/index.php?topic=82843.0

[teej212]

wow, thats simple! do you think its possible to mod that to get it completely dark when not playing?

[deadastronaut]

yep...i tried it with 3mm superbrights and they were off completely..5mm stayed on a bit ok..

you may want a 4.7k on there too..or mess with the value till you get the desired effect...

yeah its a great little simple sound to light circuit..ive put em in guitars and pedals...

good luck . rob.