Stereo not working

i would like to know if you could tell me where I would find the amp that powers the stereo speakers. All of my audio is dead and my deck is powered and working properly. I spoke with someone on the phone about the issue and they told me that there was an amp in the car separate from the actual stereo deck. He said that the problem was that the fuse was blown in that amp. So I would like to know where I can find that amp or the fuse for it.