mini compressor

mini compressor This is a circuit for a "feed-forward" dynamic compressor which, unlike a "feedback" system, does not use the output signal as a feed back into the control system. So rather than use a control loop, this circuit uses par- allel control. The diagram shows most of a feed forward set-up. The design criteria here was for a simple dynamic compressor using only one active component (Ti). The audio signal received at the input normally travels via Cl, Ri, D1, C2 and R2 to the output. However a part of the audio signal also feeds the detector of D3/D4 and sets up a control voltage for T1. The higher the value of the input audio signal, the more Ti conducts and the more current will flow from its emitter through diode Dl. This diode in turn con- ducts more and more and shorts to ground an ever greater amount of the audio signal received via R1. That, basically, is how the cir- cuit works. Diodes D3 and D4 are forward biased by T2 and R4 so that the detector can work with ev...