This is my first instructable and I plan on entering it into the "Get the Led Out!" contest. Constructive criticism is always welcomed, Also if you find this guide useful or just enjoy it, please vote and rate it.
*** Updated with circuit to make it blink when you strum! Also how to make the leds turn on when you plug in your instrument cable! See the last step!
http://www.youtube.com/watch?v=JtR5kkf7ipw heres the link to it in Action! skip to 6:00 if you don't want a video tutorial!
****There is another method of doing this that hsandford has brought up, It is a bit more complicated, but will result in much better results and have less problems overall then this method. Your can find his guide here. http://howardsandford.com/blog/flashing-leds-audio-meter-avr-attiny-guitar-pickup-wiring-sound-following-circuit/
Step 1: Materials.
1. 8x led, color of your own choice. (you can add more but they might not fit correctly in your guitar.
2. 2x resistors, make sure you have the right kind for your led.
3. pieces of wire.
4. Solder and soldering iron, other electrical tools, wire cutter, wire stripper etc.
5. 9v battery and 9v battery clip.
6. 9v battery holder, or way to hold it in place.
7. tools to remove guitar strings and pickups.
8. plastic that is semi transparent (I'll show how to make this in case you don't have anything suitable), used to diffuse the light for a better glow. a dremel tool may be needed for this, also scotch tape.
9. Extra strings in case something happens to yours, even though its very unlikely.
10. You will also need a switch of your choosing, I used a reed switch that is normally on so i can just stick a magnet to it to have it off when I'm not playing. Otherwise you will need to drill the plastic electrical cover in your guitar.
11. basic soldering and electrical knowledge.
** optional, If you are doing the led blinking version, you will need,
1. LM386n-1 op amp chip, radioshack has them for 2 dollars.
2. A 10 uF capacitor
3. various resistors to get the desired amount of blinking.
Step 2: Disassemble you guitar.
1. the strings are easy to remove, simply loosen the tuners until the strings comes out of the tuning peg, you do not need to remove it from the bridge just simply so they are not over the pickups.
2.Next we need to remove the pickups, there are usually 4 screws you want to remove, and 2 that you do not. These 2 adjust the height of the pickup. The 4 you want to remove are normally found on the corners of the pickups. Be gentle when removing the screws and especially when you move the pickup. They are connected by a wire and pulling on them to0 hard can disconnect it. see pictures for which screws to remove.
Step 3: Measuring the pickup spot.
You will need to measure the size of the hole in order to make the right sized diffuser and circuit.
In case you don't have any clear plastic pieces laying around, who does?, use an old plastic bin and cut your pieces out of it, that's how i made mine.
Now check the size to make sure it fits snugly into the hole. If all goes as planned put scotch tape on top of the plastic, I found around 4 layers gives the best effect, this helps the light spread evenly around the surface of the pickup and not just towards the center.
Step 4: Building the led circuit.
Basically the circuit is 2 sets of 4 leds hooked up in parallel.
Hsandford has a guide written up on another way of doing this, It is a bit more complicated, but will produce better results and less problems overall then this method, you can read his guide here. http://howardsandford.com/blog/flashing-leds-audio-meter-avr-attiny-guitar-pickup-wiring-sound-following-circuit/
Using your diffuser as a guide, build the part of the circuit containing the leds only. if you connect the 2 leds circuits together, there will be no way to put them into your guitar. Make sure the 4 leds will fit into your guitar with a little room to move around.
Remember to connect the leds + to - or one or the set incorrectly soldered will not work. It's a huge pain to go back and fix.
Connect wires to one of the led sets on the + and - side of the outer leds.( make these wires pretty long, they will need to be able to reach from the top of the top pickup to the bottom of the bottom pickup, so make the wire about the distance between the two.See picture.) In the next step you will connect these 2 wires to the 2nd set, and then to the battery to complete the circuit.
** Test them before going onto the next step.
Step 5: Installing the leds part 1
Find which wire is + and which is - ,(Negative is the one connected to the resistor, if you followed my diagram) if you solder the wrong wire on the first set to the wrong place on the second set, your first set will not light up.
After finding out which wire is which solder the negative wire to the resistor on your second set, and the Positive onto the open led on you second set. (see diagram)
Step 6: Installing the leds Part 2, the battery
You will need to connect a second wire to where you connected the + and - wires to the second led set.(This wire needs to reach from the hole in the second pickup to the back of the guitar where the electrical panel is. so measure it out first.)
Two get into the electrical panel, carefully remove all screws from the plastic cover, and pull the back off. Be careful not to interfere with the current wiring.
Now connect the reed switch (or other kind of switch) to the positive wire, test it first to make sure you have the positive wire and you have the switch the right way. (I connected mine on the normally closed side, so when a magnet is not present the lights will show, and when I'm not playing i can just stick a magnet onto the electrical compartment cover to turn them off.)
Then connect the reed switch to the battery clip, tape (or glue) the reed switch to the cover of the electrical compartment so a magnet will stick,and leave enough slack in the wire so you can open and close the electrical compartment whenever you need a new battery.
Last but not least connect the negative wire to the battery clip, and test it.
Step 7: Reassembling your newly modded guitar.
** Do not tighten the screws any more once they have sunk into their spots on the pickups. If you over tighten them, they will not hold and the pickup could simply fall off.
Put the strings back on, and tune them, if your bridge is like mine and comes off, make sure you put in back on correctly.
Your all done!
Enjoy your newly modded electric guitar, and show it off to your friends making them jealous.
If you don't understand anything, or if it is unclear, please ask for help. I will be more then happy to help you out.
Step 8: Optional extra features.
***Hsandford has a guide written up on another way of doing this, It is a bit more complicated, but will produce better results and less problems overall then this method, you can read his guide here. http://howardsandford.com/blog/flashing-leds-audio-meter-avr-attiny-guitar-pickup-wiring-sound-following-circuit/
Also you could make it so the lights blink when you strum, I have Successfully built this circuit and it
http://www.youtube.com/watch?v=JtR5kkf7ipw <--- link to it in action, skip to the end for me playing it, (I KNOW I SUCK AT GUITAR)!
- another thing to note is that for some reason, with the blinking circuit it seems to drain your battery even when your not playing, so to prevent this i put a magnetic switch on the positive line from my battery so when i put a magnet on the outside of the electrical panel cover it kills the battery completely.