Driving an LED with the guitar signal?

[deadastronaut]

I want to modulate the rate of an LFO with the guitar signal (strum the guitar, spike the rate). Basically just want to light up the LED in a vactrol.

ahhhhh....a guy did this very same thing with his modded version of the lightwah....i,ll see if i can find it....

[kforte318]

Here's my full schematic. I'm not fantastic at drawing them and used a pen like an idiot, so let me know if I can clear anything up. I'll have an audio sample of this circuit up in a few.

EDIT: https://vimeo.com/157351753

I recorded this brief video with my phone sitting next to my amp. A little ways in I take the LDR out of series with the rate pot, and then I disconnect the LM 386 from power. You can pretty clearly hear the latter because all of the noise in the background drops away for the remainder of the video. Any idea how I can eliminate it altogether?

[Egon Juver]

Hello guys.
I'm from Brazil and I have some doubts about something that I intend to do and that is very similar to what I read in this forum and, at the beginning, my biggest problem is to understand practically nothing of electronics. I built a fuzz pedal that can be seen at "http://tagboardeffects.blogspot.com.br/2013/02/red-fuzz.html". As per comments there on this page, I used a TL071 too but the LEDs didn't flash what is exactly what I wanted. When I started reading in this forum I thought that there could be another solution in which I do not have to discard the fuzz itself and that, by the way, is very good. I changed the diode LEDs (1N4138) and it still works fine. Being more clear and objective: I want to put an LED (or two) in the fuzz that flashes when I play (something similar to what can be seen in "https://www.youtube.com/watch?v=PH2uj9bWfM4&feature=youtu.be&t = 11 ").
Is there a solution in the fuzz itself (with some modification certainly) or can I add a small circuit as shown by the PRR a few pages back? Oh, and please, if anyone can help me I would ask it to be an explanation as if I were for a child of 5 years or less, well described in the smallest details because as I said, I understand little or nothing electronics ...
Right now, thank you folks.

[Egon Juver]

And then folks?!?!?!? Someone ?

[duck_arse]

Egon! I don't think I can tell you like a five year old, but here's some stuff. always listen to what PRR says. we usually prefer/need to see the circuit diagram itself, because it is easier to read than someone's layout, but - your TL071 will be "strong" enough, should be strong enough, to drive the PRR LM386 circuit, and you will be the one to find out, one way or another.

on yr fuzz, the line/track/trace across named "Int 1" is where you would connect the point on PRR's named "IN". connect the +9V on each board together, and connect all the grounds together, obviously. you would probably try the LM386 on a breadboard before soldering it, wouldn't you?

are you familiar with earth, ground, common? and do you know pin 1 on an IC?

[Kipper4]

Part of the problem is that most of us want to see a schematic. To get a sense of the circuit.
Then we don't have to decipher the layout.
So to make it easier.
Here's an assumed schematic (because the direct link from the layout page didn't work).
Non inverting gain/clipper op amp ,some filtering with an N channel jfet buffer at the back end.


http://www.generalguitargadgets.com/pdf/ggg_dist_redfuzz_sc.pdf

I'll take a look when I get a mo.

[Egon Juver]

Hello guys.
First of all I would like to thank your attention and tell the duck_arse that the 5 year old would be me ... 
I understand that for you to look at a scheme is more important than a layout to be able to work on something. But for me it is just the opposite because of the limitation I have in relation to electronics. Layouts work like a copy and paste for me ... and 'op amp', 'filtering with an N channel jfet buffer' sounds to me as Greek or Japanese language ...
I am not belittling anything or anyone, just explaining my electronic knowledge So I'm sorry if there was any offense with my comments. Anyway, layouts are actually the best medium for my understanding ... it's kind of a cake recipe ...
To conclude, I just made the Sound 2 Light from Deaastronaut which can be seen at "http://www.aronnelson.com/gallery/main.php/v/chickpea/sound2light2.jpg.html" and that I thought I could "adapt" to my fuzz, and guess what .. It didn't works.   
I used LEDs in series, in parallel, white, red, yellow, etc ... 
Well, for now this is it ...

[Kipper4]

Perhaps if I try to talk you through the schematic. You would recognise some of the componants etc and be able to follow.
I'd be willing to try if, you want to listen. It was all Greek to me too at one time and I still get it wrong plenty.
Maybe then we can look at debugging the sound to light.

Do you have a multimeter?

[duck_arse]

.... tell the duck_arse that the 5 year old would be me ...

if you're only 5 years old, how come your typing is so good?

how about this - you present us with the circuit, and the layout that matches it, and we can read one and refer it to the other, rather than having to decode the layout. and anyway, you'll be needing to learn circuits sooner or later.

[Egon Juver]

Hello, gentlemen. I am here again.
I do not have a multimeter. And my reasonable writing in English is due to the google translator, 
I do not pretend to learn to read / interpret circuits and I also do not intend to buy equipment to use in this, because I just want to do 3 pedals (wah, fuzz, tremolo) for my use (with my guitar that I also did myself) and after that I probably will not come back to these tasks ...
Well, the Sound to Light finally worked with 1 and with 2 LEDs, red or white; when I used 2 I had to put them in parallel and not in series. They light weakly but light up as I play. Maybe the battery is already low ... I have to change it tomorrow. And I also think there was a "cold solder" in a ground wire of the little circuit (I do not know what is called "cold solder" in English).
Thanks and I should come back with other questions.

[Egon Juver]

Hello guys.
Here I am again with my silly questions ...
Returning to the Sound to Light, I changed the battery and what happens now is that the LEDs are lit very strong and do not oscillate / flicker while I play and the sound distorts like a fuzz... For now I am testing only with the clean guitar sound.
When I come back with the previous battery (already well used) the LEDs flash weakly again ...
Still with the new battery, I tested using higher-value resistors (390R, 1K, 10K and even a 220K) and the brightness of the LEDs even decrease but they remain lit without blinking and the sound keeps distorting ...
Any idea of ​​what can be happening? Thank you, Egon.

[Egon Juver]

Hi.
I forgot that there was another question to ask: on a given pedal a ceramic capacitor of 470nF is used: since I am having difficulty finding this value, I ask if I can use 2 x 220nF in parallel?
There will be a slight difference of course (less than 10%), but would anyone have any idea how much this could affect the project? Thank you again, Egon.

[bluebunny]

The tolerance of a 470nF ceramic cap is likely more than the 30nF nominal difference you mention.  It won't make a difference and you won't notice it.

[Egon Juver]

Okay, Bluebunny.
I will then use 2 x 220nF because these I already have.
Thank you very much, Egon.

[Egon Juver]

Well folks, I made a new experience: I have an AC / DC adapter that has outputs of 1.5 - 3 - 4.5 - 6 - 7.5 - 9 - 12 Volts. I decided to use it starting with output = 1.5V and the LEDs glowed intensely without blinking and the sound came out clean. I used the 3V output and the LEDs continued to glow brightly and the sound began to distort. The same happened when I used 4.5V with increased distortion ... I stopped there for fear of "burning" the IC or the LEDs or anything else ...
I am reporting these details just so that if anyone is willing to help get more information of what is happening and reminding everyone that I am using the Sound to Light layout of Deadastronaut "http://www.aronnelson.com/gallery/main.php /v/chickpea/sound2light2.jpg.html ".
Thanks.

[Egon Juver]

Sorry, the link is "http://www.aronnelson.com/gallery/main.php/v/chickpea/sound2light2.jpg.html".