Eddie Ciletti 

Dynamics Processors 

  • Four topologies: VCA, Variable MU, FET and Opto
  • VCA has widest most linear range
  • FET and Opto are based on simple, resistive voltage divider
  • Understanding the transfer function (see image below)
  • Types of Input / Output (I/O) amplifiers
  • Transformer-less (active balanced) do not add color
  • Transformer-based gear and the circuits around them that are "colorful"
  • Purpose of dynamics processors: utilitarian and artistic
  • Utiltarian (not a religion): To limit dynamic range
  • Artistic: To create excitement
  • Downside of processing: reduction of sonic real estate
Read these articles about signal processing:
Tthe "Transfer Function" of a dynamics processor is simply the relationship between Input and Output, or more precisely, how the output is affected by the process.  This image details the relationship.  The dotted diagonal line represents no processing, above is gain, below is attenuation.