Silicon Chip Headphone Amplifier - Kit
This headphone amp kit K5611 was purchased from Dick Smith Electronics on special for $12.95. This kit doesn't appear to be available from DSE anymore.
Tried various op-amps:
In this particular headphone amp the op-amp proved relatively unimportant.
Test power supply: Single 12-0-12VAC 300VA toroid with rectifier bridge and 2 x 10,000uF filter capacitors.