Audio amplifier with transformerless power supply

Abstract

In a high-fidelity, high-power audio amplifier, the power supply makes direct connection is made to the AC line, followed by appropriate rectification and filtering, but without the need for a power transformer. The invention is not limited in terms of the class of amplifier, and may be applied at least to class A and class AB configurations. The input is AC-coupled without the use of a ground potential, preferably using capacitive coupling. To provide voltage levels appropriate for referencing and other purposes, a pseudo-ground is established, preferably through the use of a resistive ladder across the rectified line. The use of this divider network not only provides DC voltages to operate integrated components such as operational amplifiers, but also serves to provide reference signals for differential amplifiers in the output stages.

Dependencies are inferred from the claim text.