Consumer Electronics

COMPANDERS

The professional solution to the problems of limited dynamic range and poor signal to noise ratio has been overcome by the use of compression and expansion circuits called companders, Fig. 12.2. The compressor circuit boosts weak signals relative to strong signals by a preset amount, so that the range of signal amplitude is less than it was in the original signal. The compressed signal is then recorded with the peak just reaching the peak permitted recording level, so that the weakest signals are at a level well above the noise level.

 

 

Fig. 12.2 Compander action

 

On replay, the signals are passed through the expander section, ...