This project started with a location that needed headphone audio at a desk. We had an extra cat 5 running to the desk from our audio rack in the other room. So I started out by making these RJ-45 to 1/8 inch headphone jacks.

They worked but the audio was low due to attenuation over the cat 5 cable. I started with a cMoyBB v2.03 headphone amplifier from http://www.jdslabs.com/item.php?fetchitem=cMoyBB203

I removed the 1/8 inch input jack and replaced it with the RJ-45 connector. I also moved the LED from the side of the board to where the old jack was.

I notched the case on the side to connect a DC wall adapter.

This is what the final product looked like with the headphone jack on the left, power LED in the middle, and the On/Off volume knob on the right.

This project was an easy one and made the client very happy.