Stereo 4 Amplifier
This is my present stereo amplifier, designed and built in 2000. This
project is unique in that I built two - one for use in my
stereo, and another for use with my Korg keyboard.
I've been steadily improving the design of this amplifier for 25 years.
The circuit topology is fully complementary, differential, cascode,
bipolar transistor. It is direct-coupled from input to output except
for one capacitor and a DC servo. It contains two power supplies: one
unregulated supply for the output stage and a second regulated supply
for all other stages. I think this amplifier can hold its own when
compared against commercial high-end audiophile amplifiers.
The design outputs 80 watts per channel into 8 ohms and 160 watts per
channel into 4 ohms. The amplifier contains roughly 500 discrete
components. The semiconductor complement includes 94 bipolar
transistors, 168 diodes, 2 JFETs, and 2 integrated circuits.