Need help with chips!

I have a weird situation. My boyfriend Danny is out of the country, can't give too much information on him. He loves to fiddle and tinker with audio components and writes me all the time wanting me to look up information for him on chips and how to work on battery powered audio amplifiers. I'm freaking lost! No idea what he is talking about and I really need help figuring out where to find the information he is requesting. Is there anyone who can help me?
His resources are limited and what he has to work with he usually scrounges up what it's being used or cannibalizes other radios, walkmans, etc.
Help please :)