This is made possible by an output transformer design which does not saturate at high levels and has high efficiency.
12.
Two major differences are that Shure removed the hum bucking coil on the new model and added an output transformer.
13.
An output transformer in an audio amplifier or radio receiver sends only the AC to the loudspeaker, for example.
14.
The RF collector coils are all interconnected by an output transformer, whose secondary winding is connected to the antenna circuit.
15.
DC current is cancelled in the output, allowing a smaller output transformer to be used than in a single-ended amplifier.
16.
Tube amplifiers have sufficiently higher output impedances that they normally included multi-tap output transformers to better match to the driver impedance.
17.
Output transformers are not perfect devices and will always introduce some odd harmonic distortion and amplitude variation with frequency to the output signal.
18.
Valve outputs require an output transformer to match the very high output impedance and voltage of the output valves to this lower impedance.
19.
While the output transformer is represented simply by the appropriate circuit symbol, it is a component which must be designed with great care.
20.
The reason is that tube amplifiers normally use output transformers, and cannot use much negative feedback due to phase problems in transformer circuits.
