Hybrid Microphone Preamplifier With Variable Selection Of Amplifier Technology

Abstract

This paper deals with the design of a studio level hybrid microphone pre-amplifier using a vacuum tube and semiconductor technology. The pre-amplifier circuit also contains an analog VU meter, 48 V phantom power supply, variable high pass filter, phase inverter switch and adjustable stage input impedance. This paper also deals with the design of a multi-voltage power supply unit and microprocessor controller unit ensuring completely automatic amplifier functions. The end of the paper is dedicated to a characteristics measurement determining its parameters.