Author Topic: Sound 2 Light with LM386N-3?  (Read 1224 times)

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bluesdevil

Sound 2 Light with LM386N-3?
« on: February 14, 2012, 04:25:45 PM »
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!
« Last Edit: February 14, 2012, 04:30:55 PM by bluesdevil »
"I like the box caps because when I'm done populating the board it looks like a little city....and I'm the Mayor!" - armdnrdy

deadastronaut

Re: Sound 2 Light with LM386N-3?
« Reply #1 on: February 14, 2012, 10:55:08 PM »
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....
« Last Edit: February 14, 2012, 11:13:51 PM by deadastronaut »
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bluesdevil

Re: Sound 2 Light with LM386N-3?
« Reply #2 on: February 14, 2012, 11:57:39 PM »
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:
"I like the box caps because when I'm done populating the board it looks like a little city....and I'm the Mayor!" - armdnrdy

deadastronaut

Re: Sound 2 Light with LM386N-3?
« Reply #3 on: February 15, 2012, 12:20:13 AM »
cool, glad you got it going man!... ;)
http://www.youtube.com/user/100roberthenry
http://deadastronaut.wix.com/index

^ CHASM REVERB / TREMSHIFTER / FAZE FILTER/ABDUCTOR II DELAY pcb's + WAH LIGHT PLATES.

Gurner

Re: Sound 2 Light with LM386N-3?
« Reply #4 on: February 15, 2012, 01:19:43 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.

bluesdevil

Re: Sound 2 Light with LM386N-3?
« Reply #5 on: February 15, 2012, 10:29:16 AM »
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.
« Last Edit: February 15, 2012, 04:34:19 PM by bluesdevil »
"I like the box caps because when I'm done populating the board it looks like a little city....and I'm the Mayor!" - armdnrdy

artifus

Re: Sound 2 Light with LM386N-3?
« Reply #6 on: February 16, 2012, 09:18:08 AM »
have you tried a large parallel capacitor across the leds? series cap may soften the attack too.

bluesdevil

Re: Sound 2 Light with LM386N-3?
« Reply #7 on: February 16, 2012, 05:04:21 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.
"I like the box caps because when I'm done populating the board it looks like a little city....and I'm the Mayor!" - armdnrdy