Hi frankwas! This link will give you an idea about how it looks like in your car amplifier, guess you need at least 1000VA transformer for your amplifier if you want to rock real hard, 1400W that is lots of power, your amplifier might have more than two channels, can you take a snap shot of the inside?. Open the ampifier and run it from a 12 volt battery if you don't have a power supply that can handle the current needed. Measure from the the center tap of the transformer to the + and - side of the rectifier, the voltage reading you get is what you need ;) The bridge rectifier usually consists of two 3-leg devices TO220 packages with two diodes in each, they are usually marked with diodes on their bodies and mounted to the heath sink. Someone will probably say that a bigger transformer is needed and that is both true and false, all depends on how loud you want to play ;D http://sound.westhost.com/project89.htm