Techo!pedia

Car amp

A friend of mine gave me an old stereo...after ripping the cd player apart to get his cds out... that he claimed ate some of his cds... Since the stereo in my car died and with no money at the moment I decided to make this temporary car amp...

This is what the stereo looks like out side of the case with the cd player removed:

SInce the cd player no longer works there is no need to leave the motors still attached. I tried unhooking this daughter board completely, but the stereo will not stay on without it attached.

This is what the board will look like after the motors have been detached: I used a dremel witha cutting wheel to cut the board.

The problem of power arises, so I break out the voltage meeter and discover that the internal transformer was producing 12 volts, the same as a car. I decide to dissconnect the transformer and splice in a cigarette lighter power cord because the output in a car is also 12 volts. I could have eliminated this board all together, but I figured that it was a good idea to leave the fuses for protection.

I wasn't completely sure wich was negative and wich was posotive so I looked it up and then made the proper connections.
Below is a pinout of a cigarett lighter plug:

I discovered the input for audio from the cd player, I tried using the tape player input, but it was very distorted. With a little force the audio cord from the back of an old cd drive will fit the socket. I cut off the other end of the cord and sodder on two rca female connectors (right and left). A minni jack would have been more practicle, but I already had this cord made so I didn't moddify it. The two far left pins on this connector should be soddered together.

To make sure everything worked I drove around with it contained in this yellow case.

Closed:

I tapped the controlls on the outside temporaily for easy access...

After testing the prototype I realized that it was a pain in the ass tohave to reach in the back of the car to turn the volume up on power off. I thought of all of the buttons that I thought I might need to use while driving... I decided I would need the Power button, power led, the two volume buttions, bass boost led, and the bass boost button. After mapping out all the components and the paths of the 4 buttons I then came up with this diagram:

I made the board using a cheap pcb I bought at radio shack. Then I rolled out 8, 8 foot sections of insulated wire and twisted it together. Next I soldered the ends to the appropriate connections and here is the semi-finished product:

Close up:

Afther all that was finished I trimmed off the extra board and attacherd it to a floppy hole cover.

While dumpster diving at my school I found an old mac and scavenged the case from it, after a few modifications to the case everything fit inside perfectly...

I dremeled a hole for the speaker connections and attached the rca inputs

I made a bracket to hold the wires inplace and keep them from pulling out.

I put the top of the case on and vala... after marking the apple logo out with a sharpy it is ready to go.

back:

I installed it in the back window of my car on the passengers side so it didn't interfere with my view... It fit perfectly... I ran the green cords from the back on the passenger side, tucking them under panels when possible.