Direct current coupled cascaded transistor amplifier for providing high output voltage to electrostatic loudspeaker of high end stereo system, has optoelectronic coupler bridging potential difference between pre-stage and driver stages

摘要

The amplifier has four cascaded identical transistors forming a bridge circuit, where a power supply for an end stage and a load lies at a diagonal of the circuit. An input signal is segmented into positive and negative half-cycles in a pre-stage for separately controlling 4 cascades of the end stage. Optoelectronic couplers (OCS1, OCS2) bridge a potential difference between the pre-stage and driver stages, and are provided with a LED. A linearity and phase input of the couplers are controlled by degenerative coupling of an output of the amplifier to the pre-stage.