Introduction: Music LEDs

LEDs glowing to the music signals sent from PC motherboard audio header.

Step 1: Things Needed

  1. LED strips.
  2. TIP 31 transistor.
  3. 12V power supply(this is optional, you can use the 12V rail off from the PCs power supply itself) for switching on/off when required.
  4. The AC'97 cable(You will need to unplug this from the front panel and connect some wires. YES!!, my way of connecting the wires in the image shown looks filthy, but I was just trying out. Later i managed to make it look much cleaner, so yay :D ).

Step 2: The Circuit

The AC'97 audio out cable has ports 5 and 9 for right and left audio signal output, emitter of the transistor is connected to these ports.

port 2 is the ground to which base of the emitter and the negative terminal of the power supply is connected.

Step 3: Configuration in PC(by Audio Manager S/w)

  1. The header should output AC'97 audio, this can be done through BIOS or by the audio manager software(I did it through audio manager itself since I'm pretty lazy).
  2. The PC volume must be at 100% for the LEDs to work.
  3. The setting "Mute the rear output device, when a front headphone plugged in" should be used. This actually doesn't mute your speakers, not to worry.
  4. Follow the picture guide to make these settings.

NOTE : I take no responsibility if in case, God forbid, something happens to you(none of the currents inside your PC can actually harm you, except the PSU) or your PC or your devices. This is working super fine for me without any trouble :).

Also note that when I was testing this with the RCA cable, my speakers went "whounnnnnnnn" and my monitor flickered a lot :| . So, just a heads up if you're pretty crazy like me.

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