The Class-G Power Amplifier.

Class-G amplifiers are now gaining greater acceptance than ever before, due to their high efficency. However, reservations about their distortion performance have often been expressed. Douglas Self's innovative design removes the compromises and has linearity approaching that of his other designs.
The Douglas Self Class-G power amplifier uses a simple but elegant technique to increase amplifier efficiency and reduce power consumption. The design is described in detail in Electronics World for December 2001, and Jan, Feb 2002. The PCB includes the Class-G mode indicator described in the Feb 2002 article.

Please note the PCB is currently available exclusively from Electronics World, but the kit of parts may be ordered from us now.

  • Exceptionally low distortion. Almost certainly the lowest distortion Class-G amplifier ever produced. No glitching due to diode turn-off problems.
  • Very low noise, due to innovative feedback design.
  • Full overload and short-circuit protection.
  • Optional input bootstrapping to raise input impedance.
  • Board fixing holes and pads provided for easy mounting of TO3P output devices and power diodes to a heatsink.
  • Alternative input transistor positions provided allowing different types to be fitted.
  • No difficult-to-obtain components.
  • High-quality double-sided plated-through-hole fibreglass PCB with solder mask both sides and full screen print.
    Board size 178 by 105 mm overall.

PCB price: £33.00
Kit price: £125.00
Please note that the kit includes the PCB. It makes up one PCB which is one audio channel.
KIT CONTENTS. The power amplifier kits do not include:
The main heatsink, transformer, power supply components, case.