LEDs Sync to Music (with Pics of My Awesome Computer Case Mod)


Introduction: LEDs Sync to Music (with Pics of My Awesome Computer Case Mod)

 I'm finishing up my computer table i've been working on and one of the final touches is making LEDs sync to the speakers.  I have some pics of my computer too.  This project took me about 15 minutes and was free because i had the parts laying around.  

Step 1: Materials


-TIP31 transistor

-4 LEDs or 12v led strips


-on/off switch

-3.5mm jacks (1 male and 1 female)



-soldering iron

-wire strippers/cutters

Step 2: Build the Circuit

 Here is the circuit i used.  For the 12v power supply i found a spare molex connector from the computer power supply and cut it. I used a multi meter to find which 2 was the positive and negative.  (for me the yellow was positive and the black wire beside it was negative).  Be careful when doing this and make sure the computer is off to prevent the risk of electric shock. (im not responsible if you get shocked or hurt).   If you have any questions just comment below.

Step 3: Hooking It Up

Plug in the computer speakers into the audio jack and plug in the male audio jack from the circuit into where you would normally plug in the speakers.   Mount the LEDs and switch.  Now turn it on and put some music on.  

Step 4: Pics of My Computer and Vids of Lights Working

 I'm going to finish it when i get some glass, i just have to put a back and top on it and put a piece of glass over the screen. please rate and comment. (:



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    i get a bad crackle like distortion from sound, the lights work but yeah i cant handle how bad the sound becomes with it on, how do i fix it?


    another question:

    i bought an TIP31C transitor

    this transistor also good??

    2 replies

    well i havn't used it before, but yeah i think it should work. ive read things about where people have used them

    my experience is that several different transistor will work.


    This is great, works fine here.
    I want it to pulse with the bass *only*. Is there a way to make a filter for it ? thanks

    2 replies

    Yes, there are ways to "pulse" bass only or rather to "pulse" at a certain frequency. To achieve a pulse a certain frequency you need the correct IC, Capacitors and Resistors, you also need to know how to connect it all - I know how to read a schematic and set up a circuit, but I do not know how to achieve a certain "pass filter' without someone telling me the capacitor and resistor values.

    Hmm honestly I'm not sure. I guess you could connect only a subwoofer or something to this to get the effect. But i don't know of a filter or anything

    Thank you for making this instructable i tried this out and it worked grate. one thing i used this diagram in making a led synced music cabinet the only difference is my leds are in parallel and the power supply is only 5v well when the bass hits and the leds go off i get some weird distortion in the music just wondering if any one knows what i did wrong

    what will be if i don't put an on/of switch

    1 reply

    if you dont put on an on/off switch then it will be always be on

    I hope you know better than to touch the inside of the power supply..

    5 replies

    Yeah, its just common sense. all i did was take the top off of it for better cooling.

    Whoa dude you have some balls to do that! Anyways, nice tutorial, may try to do it in the future!

    You're welcome!