CHAPTER 17
Microphone Preamplifiers
Microphone Types
There are many ways to make a microphone [1], but for our purposes, there are three main types:
- The dynamic microphone, which consists of a diaphragm that moves a coil of wire in a strong magnetic field. Output -80 to 0 dBu, the higher level only occurring when you put a microphone inside a bass drum. Phantom power is not required.
- The capacitor microphone, where the diaphragm forms one plate of a capacitor with a constant charge applied via a very high value resistor –typically 10 GΩ (yes, 1000 MΩ, a specialised part) so that variations in the capacitance cause voltage variations. There will be a head amplifier built into the microphone body that brings the output up to about the same as ...
