Handbook for Sound Engineers, 4th Edition

Chapter 21

 

Preamplifiers and Mixers

 

by Bill Whitlock and Michael Pettersen

21.1 Microphone Preamplifier Fundamentals

21.1.1 The Microphone as a Signal Source

21.1.1.1 Electrical Model of the Microphone

21.1.1.2 Interactions with Preamplifier and Cable

21.1.2 Some Considerations in Practical Preamplifiers

21.1.2.1 Gain and Headroom

21.1.2.2 Input Impedance

21.1.2.3 Noise

21.1.2.4 Bandwidth and Phase Distortion

21.1.2.5 Common-Mode Rejection, Phantom Power, and RF Immunity

21.2 Real-World Preamp and Mixer Designs

21.2.1 Transformers

21.2.2 Class A Circuitry

21.2.3 Shure SCM268 Four-Channel Mixer

21.2.4 Cooper Sound CS 104 Four-Channel ENG Mixer

21.2.5 Jensen-Hardy Twin-Servo® 990 Microphone Preamplifier

21.3 21.3 Automatic Microphone Mixers ...