Reg Edwards wrote:
Bipolar and MOSFET amplifiers are by comparison low impedance

devices

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Actually they are not. But everything else you say is quite correct.


Well their INPUT IMPEDANCE can be high, but their
OUTPUT IMPEDANCE when used as a power amp is just as
low as bipolar transistors, so the broadband transformers
are just as valid. And as far as their input impedance,
well these are class AB or B power amps, so they take
some driving power. In this case because of the required
driving power, the input impedance isn't very high.