This is an amp that I built, in stages…

A fairly simple amplifier that features a 'breathing' power led and 10 led volume meter... (needs more leds)

The first thing I did was build a simple line out amplifier for a couple of unpowered speakers that I found. Following that I built a plexiglass case around it and added the breathing power led and 10 led volume meter. I think all speakers should have a circular led volume meter built into them. It would help deaf people figure out why people at dance clubs are so weird and it just plain looks cool.

Some of the components in this setup are older or difficult to find, especially in the amplifier circuit, which uses a TDA IC that is not in production anymore. I do some of my shopping at a local electronics place in melbourne, fl called Astro Too; they buy lots of deprecated electronic components in bulk from places like Harris and desolder and resell the inner goodies like high tech pinatas. If you’re interested in making one of these for yourself I’d like to suggest a few circuit diagrams:

Amp – This simple audio circuit uses the TDA2003 which is available from mouser

LED volume meter – Here is the circuit I used for the LED volume meter

Pulsing LED – And here is the final component, the ‘breathing’ or ‘pulsing’ power led; a simple circuit based on a 555 ic. (in the video below it’s the red led at the top of the amp)

If you’re interested in doing this project but aren’t an electrical engineer, I’d still go for it! The schematics that I’ve provided all use components that are available in ‘through hole’ versions and you end up with a pretty neat, useful toy for your effort. :)

Here are some pictures that I took and decided not to use a gausian blur filter set to, “shit, that hurts my eyes”, or “Is this picture giving me a headache or do I have a tumor?”. Enjoy.

An amplifier filled with leds for the sake of leds

Close-up of the LED goodness

This potentiameter controls the amplitude of the led display

The control boards for the leds, the hardware equivalent of designing an organism with it's intestines on the outside!

Lastly, here’s a dark, blurry youtube video of the device amplifying music, until youtube removes the audio for copyright reasons because this is a clear violation of copyright law and not fair use, sorry about that RIAA, am I still in the will? :(

π