PA4 - 2x300W/4ohm Solid State Power Amplifier
This amplifier was inspired by conversation with John Curl in a ‘Blowtorch thread’, as well as by his thoughts ( http://www.parasound.com/pdfs/JCinterview.pdf ).
The aim was to build a reliable, solid, good sounding amplifier. Topology of the amplifier is complementary differential, with JFET input, MOSFET cascode and VAS, and BJT output stage with 4 pairs of 15A transistors.
Simplified, basic schematics is shown in the following image:
Solid state, dual mono design, stereo power amplifier. Inputs: 1 pair balanced (WLR). Outputs: 2 pairs binding posts. Protection circuits: DC output, AC current overload, DC current overload.
Distortion spectrum at 50W/8 ohm
The PA4 amplifier photos
Pavel Macura, 10/2009 - 09/2011