Led Brightness Controlled By Guitar Signal

[Neta]

Hi

I'm building a pedalboard and I want to add a glowing light on the bottom, that will get stronger and weaker according to the guitar signal.
I'm don't understand too much in electricity (first solder iron on its way ) so I'll be very glad if you could explain in a simple manner.
If you could just tell me what parts do I need and what connects to where, I'll try to figure the rest out myself..

Thank you very much!

[Hemmel]

Hello Neta and welcome to DIYSB !

You can read this thread and this thread which are both from this forum.

Also, you could follow the answers provided in this instructable

[smallbearelec]

Actually, what you describe is the input circuit of numerous effects--like noise gates and envelope-controlled filters--that are triggered by picking dynamics.

What you want to do is entirely possible, but there is a Loooong learning curve between buying your first soldering iron and being able to "snip out" part of a schematic and bend it to your purposes. Slow down, and learn to build something simple first. Here is a link to my list of common beginner mistakes:

https://www.smallbearelec.com/HowTos/BeginnerArticle/BeginnerDos.htm

You are getting to read it early, and I hope it's helpful.

SD

[Mark Hammer]

Do you need/want the LED light to linger like a fading comet trail, or is a little blip sufficient?  Your answer will help dictate which of several tweaks to the relevant circuits are suggested.

[Neta]

Thank you both for the super quick replies

Before I came to this forum I did A LOT of googling (A LOT ) and I actually came across all 3 of these links. I afraid I understood nothing.

But, I did come across this: http://hacknmod.com/hack/led-light-box-thumps-to-your-music/

Does converting this circuit to "guitar way" (so it outputs the signal to amp without changing it) really makes it that complicated?
If it does, I'll just drop it...

Anyway thanks again!

Edit: You're replying quicker than I write

I want the LEDs to linger. It's ok for it to get delayed behind the guitar (like if I go from quite to LOUD it can have a second to adjust). In my eyes, it should just be a cool effect to put in the background and not an eye catching kind of thing.
Although I will settle for anything that works!

[Mark Hammer]

About 6 or 7 years ago, I adapted the envelope follower in the Dr. Q for a "robot" Halloween mask for my younger son.  Instead of using a silicon diode, I used a pair of LEDs, and wired up a little electret mic capsule to the input.  I installed the LEDs in the nose/nostrils of the mask, and whenever the wearer would speak, the nostrils would briefly light up for about 500-1200msec.

Now, this assumed the LED only needed to be visible in one very localized spot, and from a reasonably close distance.  Clearly, if it is simple enough to do with voice, you can do it with guitar, but what sort of visibility are you imagining.  Is this something you want to be visible on a stage?  Is it a lttle private joke you want to carry out?  The conversion of signal strength into light is simple enough to accomplish.  But if you want something akin to the old Rickenbacker "lightshow" guitar, that is an order of complexity higher.

So, what's it gonna be?

[Neta]

No no no no, this is nothing big at all.
I was looking for ways to modify the pedalboard, make it cooler. I thought a glowing light on the bottom or between the pedals that changes to the intensity of playing is awesome.

It's not something for a stage, or anything like that. It's really small, should be the simplest thing.  I thought about using a microphone but then it would light up when there are other noises too.

[smallbearelec]

I did come across this: http://hacknmod.com/hack/led-light-box-thumps-to-your-music/
Does converting this circuit to "guitar way" (so it outputs the signal to amp without changing it) really makes it that complicated?

It's complicated if you have never done any circuit-bending, not too bad with some experience. Mark mentioned the envelope follower circuit in the Doctor Q pedal; that will give you a voltage that varies with your picking dynamics. What you would do is get this working on a breadboard, then experiment with using it as input to an LED driver similar to what is shown in the above link. Not crazy, but a steep learning curve for a beginner. I hope you back up a little, learn some basics and then go back to this idea, because it is a good one.

[PRR]

> I did come across this

That will not light-up with guitar-type signals. They need to be stronger.

Even with stonger sources (iPod?) it is likely to distort the signal (which you might want to hear as well as see).

"Hack" is being polite. There is a slim range between not-working, and smoking all the LEDs or the TIP transistor.

Aim toward something like the Ruby Amp. Having a dinky utility amplifier is very useful for testing or after-midnite jams; you can also hang a resistor and LEDs off the output.

[mistahead]

Sorry - I'm missing what the issue is with just splitting off some signal at a buffered Y, using it as the input (base or collector gah?) with a battery (at the other input). Pot the battery input and use it so you can control the resulting voltage and put the output to some LEDs.

We're not trying to create an accurate level meter on a scale, we don't really need to know if its the attack or the decay part of the strum that is making the LED dim (in or out), we just want some flashy lights on the pedal board for when there is guitar signal present right?

[stallik]

This circuit has already been done by deadastronaut.
http://www.diystompboxes.com/smfforum/index.php?topic=82843.0
I've put it on my acrylic pedalboard and its awesome though a little pretentious. Only issue I had was a slight noise due to some kind of interaction with my power supply so I simply run it off a 9v battery to avoid the problem.
I've put the circuit into a small enclosure and run the 2 LEDs out of the box on insulated stalks. I put a length of heat shrink over the LEDs to mask extraneous light and just push the unit up to the board, stand back and watch the blinking lights. Oh I've also put in an on/off switch to save the battery.

[Neta]

That does look simple enough, (Although I thought you need to manually program ICs..)
But that doesn't really have an output too, no? 
I only saw input, battery and ground.
Thanks again!

[stallik]

You just take a single wire from your signal and run this in parallel. A y cord if you like.

[Neta]

and that wouldn't mess with the sound?

what actually gets "cut" in something like that? (Current etc.)

Thanks

[Pojo]

If you implement a buffered splitter you can avoid loading down your signal.

http://www.muzique.com/lab/splitter.htm

[MrStab]

from my experience doing this in various ways:

deadastronaut's method will work in both instances, however - as others have stated - if you're using an unaffected guitar signal, you may want to put a buffer before the LM386. if you're using a strong, post-gain signal, you can get away with using an NPN.

not plugged in unfortunately, but i did this ages ago because i have no life (has a buffer in it):

[Neta]

So basically, this part is between the guitar and amp, before the pedals unless I want the effects to count.
This is the first part of it:


And this is the second part:


After that, it should work as I want.

Ok, I just have a few more questions.
Do I need to program the IC manually? After all, it's a chip. It comes ready with what I need it to do?
And secondly, can I do all of this on a regular breadboard? Seems like it would fill one up completely.

Thank you very much!

[stallik]

 You need to read through the posts on the previous link. There is an extra 10uf capacitor which you have not noticed. As I mentioned before, the only change to my sound was a slight hum which only occurred when running the circuit on the same power supply as my other pedals. Running it from a 9v battery makes it quiet and very transparent. With no buffers anywhere

2 components plus 2 LEDs - go to be worth trying like this to see if it suits your purpose

[MrStab]

doubt it'll be much help, but here's the circuit i made combining the simple opamp buffer from AMZ (http://www.muzique.com/news/opamp-buffer-layout/) with the Sound2Light:



please bear in mind it's from my earlier days of FX making (although i still have much to learn), but i can confirm it works. there was some debate at the time as to whether i should have 9V+ going to LM386 Pin 6 or pin 7, but 6 worked for me. much can probably be improved, a polarity protection diode for starters.

[Neta]

You need to read through the posts on the previous link. There is an extra 10uf capacitor which you have not noticed. As I mentioned before, the only change to my sound was a slight hum which only occurred when running the circuit on the same power supply as my other pedals. Running it from a 9v battery makes it quiet and very transparent. With no buffers anywhere

2 components plus 2 LEDs - go to be worth trying like this to see if it suits your purpose

It's weird that I missed a piece, as I copied the image from the link itself...
I'll try without the buffer, although here in Israel every part takes a long time to get here, so the IC alone would take a long time too.

And thanks MrStab! It might come in handy actually.

Btw, assuming I completed it and it works, but the LEDs change too quickly for my taste. How would I make them change their brightness slower? (like delay a bit behind the guitar)

Thank you once again!!