The PPA is ppl's Portable Amplifier. ppl has been building and advocating Jung multiloop type buffered headphone amp designs.
http://tangentsoft.net/audio/ppa/amp/
Uses National Semiconductor LM3876 Power IC. Voltage gain is 27dB.
http://sound.westhost.com/project19.htm
200W audio amplifier solution using multiple LM336s and and design concept to reach even higher output power levels.
http://www.national.com/appinfo/audio/files/BPA-200_Application_Note.pdf
A commercial Class D Amplifier, complete schematics in pdf format.
http://www.crestaudio.com/media/pdf/lt_schematic.pdf
This article is for those who wants to make their own car amplifier. In this article, I will discussed the car power amplifier in 3 steps : 1.The design of audio power amplifier, 2. The design of DC-DC converter, 3. Miscellenous tips for making car power amplifier.
http://members.tripod.com/valveaudio/Membuatsendiri.htm
The LM3886 is a high-performance audio power amplifier capable of delivering 68W of continuous average power to a 4Ohm load and 38W into 8Ohm with 0.1% THD+N from 20Hz-20kHz
http://www.saunalahti.fi/elepal/vahvistin/vahvistin1.html
Source: National Semiconductor Linear-Applications-Handbook. Vo = µ/2 = 500; µ = Yfs / Yos
http://www.electronics.50g.com/cuhga.htm
Here is a little audio amplifier similar to what you might find in a small transistor radio.
http://ourworld.compuserve.com/homepages/Bill_Bowden/page8.htm