Mnats FET/500 Compressor/Limiter Kits

Projects > Mnats FET/500 Compressor/Limiter Kits

The FET/500 series of kits are 500-series adaptation of the famous 1176 compressions. The kits are the result of a six-year design effort by Mako Natsume in collaboration with Hairball Audio. Full and partial kits are available from Hairball Audio.


  • 3 kit variations
    • Rev. A: “Blue stripe” version, noted for possessing more pronounced distortion characteristics
    • Rev. D: “Blackface” version; uses “low noise” circuitry and makes minor changes to the compression and line stages
    • Rev. F: “Silverface” version; substitutes 1109 Class A/B output stage for the 1108 Class A stage used in previous revisions, resulting in more gain and a more transparent sound
  • Ed Anderson reproduction input and output transformers
  • Hand-matched FETs
  • Complete faithfulness to the original circuits, with the exception of power supply
    • Power supply uses a low-noise method of generating the 1176 +30V/-10V rails not previously seen on 500-series units
  • Features two bypass modes, “GR off” (signal still runs through the circuitry) and true bypass
  • Simultaneous gain-reduction and output metering


  • $425 for full kit
  • $40 for basic PCB kit

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