Diode Bridge Compressors

 In TSM Studio Blog
  • In contrast to more frequently used gain control designs such as FET, OPTO, and VCA compressors, the Diode Bridge compressor circuit takes a more drastic approach to coloring a source signal. Where OPTO and VCA compressors generally do not produce a high total harmonic distortion (THD) level, diode bridge compressors turn things up a notch.
  • A diode bridge compressor uses a diode to manipulate gain-reduction, but what exactly is a diode? A diode is a non-linear electronic component that conducts electrical currents extremely well in a single direction but is frequently paired with a high degree of distortion. To rectify this “problem”, a pad was placed in front of the diode bridge to reduce the amplitude by 40 dB. In turn, this brought down the signal level along with the distortion level. In succession, the diode bridge controlling the gain-reduction and the signal is sent to a second transformer that passes the signal to an amplifier chain.
  • Due to the high noise floor associated with diode bridge compressors, other gain control elements are more ideal for a cleaner sound. However, the color and thickness that are characterized by diode bridge designs are tough to replicate. With improvements in technology, diode bridge designs have progressed to the point where the noise floor can be minimized in modern designs in comparison to vintage builds.
  • Examples of diode bridge compressors include:
  • Neve 33609
  • Neve 2254
  • AMS Neve 226
  • Buzz Audio DBC 20
  • DB54