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.

Features:

• 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

Price:

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

More Information:

• Available from Hairball Audio
• FET/500 design notes and assembly guide from Mnats.net