The amplifiers used in this instructable can be taken from old Wall outlet chargers. The kind you charge a phone with.
BTW if i can ill get a better camera instead of taking picks with an ipod and make a phone tap that clips onto the wire and pins connect to the wires and it will have an internal recording module with a micro SD card slot and run off the power of the Phone line itself. I have everything set up already. i just need the module.
Step 1: Tools
And some cutting tools