Flashing LED

[TIMBO]

Hi guys, Is it possible to get a LED to flash in time to strumming/playing?

[shooter]

yep, a little early to come up with something.   I did a circuit that would sample the input n move meter needles to the audio.  might even have breadboarded.  never made it to an amp though. 

[shooter]

can't find my "version"
this is a simple bar graph LED flasher, with some tweaks to scale your signal to the circuits design, it should work.


Bargraph Voltage Indicator - Circuit Classics

[ShoemanGB]

A search shows plenty of DIY info, some simple some not, and there are commercial products out there that use LED strips if you want a big show.  I have a set up in my music room I bought that runs 6 LED strips, each a different color and each assigned a specific freq band.  It's pretty cool if you like that sort of thing.  My own little Phish light show as I play along to you-tube backing tracks.
 Here's a DIY I just found:
https://www.allaboutcircuits.com/projects/make-an-analog-sound-reactive-led-strip/

[66Strat]

I don't know about LEDs, but Magic Eye tubes that were used in old radio tuners have been successfully implemented in audio circuits.

https://www.youtube.com/watch?v=FQAKs-Qh4DI

[TIMBO]

Thanks guys.
I'm looking to mount a LED in the EYE of the snake.

[66Strat]

That's a nice looking cabinet.

[PRR]

Try this. Experiment. Plan to blow stuff up.

Goes across the loudspeaker.

Basically it emphasizes "attack", the rising envelope. It might never light for glass harmonica (slooow rise), it ought to be percussive on guitar. I can't pre-plan the timing, vary the "Taste" capacitor 30u to 3,000u so it winks alluringly or alarmingly.

By working on "attack", it is less sensitive to absolute level. So it should blip through most of a soft passage, without getting stuck-on in a loud passage.

The 18VDC was already on my sim. At least 10V, but over 40V makes trouble for 2-cent transistors.

There may be another voltage problem: Over 7V peak signal may blow the transistor BE junction. Or not right away. Or not at all. If more than one dies "for no reason", wire a 1K or 5K trimmer as a "volume control" in front of this and start halfway up.

[Blueboozer]

I’m sure there’s a better way to do this, but, if you take an LED, attach a resistor (size appears to be debatable) to the positive lead. Attach a red wire to the resistor, heat shrink some protection over the resistor. Attach a black wire to the negative side of the LED.  Attach the red wire to the positive speaker terminal and the black wire to the negative speaker terminal. Now you’ll get blinky, blinky with the sound coming out the speaker.

Quick and dirty. But it does work. I installed a blue LED on my dummy load so I will know it’s working.

Of course use at your own risk. I’m not going to push my little blinker very hard and for very long. It’s most probably going to mess up your ohm rating for your speaker, but not enough to fry anything. My daughter has her vehicle lit up on the inside using this method. Would annoy the crap outa me all that blinking while driving.

[PRR]

??

[TIMBO]

Thanks PRR, Just what I was looking for.