The output devices are MJL4281A (NPN) and MJL4302A (PNP), and feature high bandwidth, excellent SOA
http://sound.westhost.com/project3a.htm
Input sensitivity for 60 W output - just under 1V.
http://sound.westhost.com/project03.htm
Low-cut and Bass controls Output power: 40W into 8 Ohm and 60W into 4 Ohm loads
http://www.redcircuits.com/Page66.htm
This is a handy, easy to build general purpose 50 watt amp. The amp has an input for a radio, TV, stereo or other line level device. It also has a phono input for a record player, guitar, microphone or other un-amplified source.
http://www.electronics-lab.com/projects/audio/004/index.html
360 Watt Audio Amplifier Schematic diagram.
http://www.freeinfosociety.com/electronics/schemview.php?id=726
380 Watt Addio Amplifier Schematic Diagram and components.
http://www.freeinfosociety.com/electronics/schemview.php?id=727
Experimential power amplifier using the low-cost LM3886 monolithic power amp IC. Suitable for sound reinforcement in small to mid-sized clubs.
http://home.pacbell.net/lengal/ip/lm3886.pdf
This simple audio power amplifier was originally designed for a circuit board workshop, conducted by the OSU IEEE Student Group.
http://www.pjrc.com/tech/cbw/index.html
50W output power into 8 ohms
http://www.circuithut.com/index.php?/circuit/content/view/full/380
the gain for audio frequencies is 31 (30dB), which means an input sensitivity of 700mV for an output of 60W.
http://sound.westhost.com/project12.htm