I'm trying to get the "Sound 2 Light" circuit to work as a gate for my Anderton Ring Modulator build, but the LED stays on whether the input of the op amp is connected or not. I'm using a LM386n-3 instead of the LM386n-1 that's noted here:
http://www.aronnelson.com/gallery/main.php/v/chickpea/sound2light_.jpg.html
http://www.diystompboxes.com/smfforum/index.php?topic=82843.0
Could that be the problem? Also gets VERY hot.
Can't believe I'm muffing up such a simple circuit!
hmmmm never used a -3 only a lm386n-1...
hold on ill bread it and see where it might be going moody...
ok, here goes, use input pin 3 (sorry wrong input on the diagram ::)) , and use 2 superbright 5mm blues in series, and a 470r-1k(adjust resistor value to taste/response) to ground, ...it wont go off/on with just 1 led...
its working fine on my breadboard.with lm386n-1.. ;) let us know how you get on...
i'll try it with a lm386n-3 and see if it gets hot... ;)
note the thread version is input 3....
Thanks for replying, Rob. You are right, it doesn't work with just one LED..... 2 in series did the trick and no heating up of the 386n-3!!!
Now on to try it with a LDR to see if I can make some of gate with it. Really cool circuit, thanks for sharing it! :icon_twisted:
cool, glad you got it going man!... ;)
Quote from: bluesdevil on February 15, 2012, 04:57:39 AM
Thanks for replying, Rob. You are right, it doesn't work with just one LED..... 2 in series did the trick and no heating up of the 386n-3!!!
Now on to try it with a LDR to see if I can make some of gate with it. Really cool circuit, thanks for sharing it! :icon_twisted:
Just be warned - gate circuits normally need a degree of precision - & the led brightness as driven by the Lm386 will fade along with battery voltage, unless you regulate the supply to the Lm386, you'll end up with a different 'gate' point as the battery afeds.
No battery used, just an adapter for power, so hopefully that will help get it tuned in.... haven't had time to hook it all up yet, but soon!
***UPDATE***
Okay, it worked, but the decay ended up being a bit quicker than I wanted so I may just go with a separate noise gate pedal after it to squelch the carrier feedback.
I found a post with Mark Hammer suggesting to use the envelope follower in Dr. Q to do what I wanted to do with the LED/LDR combo, but I'm not quite sophisticated enough to figure it out.
have you tried a large parallel capacitor across the leds? series cap may soften the attack too.
Quote from: artifus on February 16, 2012, 02:18:08 PM
have you tried a large parallel capacitor across the leds? series cap may soften the attack too.
Thanks Artifus for your reply. I tried a cap across LED's, but they would not light with it.
Before boxing up I might try the Mark Hammer fix by using Dr. Q envelope follower circuit fragment.... if I can figure it out.