Title :
A low-noise microphone preamplifier
Author_Institution :
University of Cincinnati, Cincinnati, Ohio
Abstract :
This paper describes a low-noise two-transistor pre-amplifier which has been developed for use with microphones. For a source resistance of 1000 Ω, a noise figure of 1.3 db has been achieved. A corresponding middle-frequency gain of 40 db, bandwidth of 30 kc and output impedance of 175 Ω resulted.
Keywords :
Capacitors; Circuit noise; Coupling circuits; Impedance; Low-noise amplifiers; Microphones; Power supplies; Preamplifiers; Resistors; Voltage;
Journal_Title :
Audio, IRE Transactions on
DOI :
10.1109/TAU.1961.1166318
