IJ Research F76 FET Compressor

Projects > IJ Research F76 FET Compressor

The F76 is a compressor inspired by the Urei 1176 that will fill one slot in a 500-series or 51x Alliance rack. The F76 maintains the compression circuit of the original while expanding the 1176’s tonal palette with several amplifier options. Builders can choose between the original amps, Igor’s own discrete opamp design, IC-based input and output amps, or any exisiting DOA with the API2520 footprint.

Notable Features:

  • “Slam” switch duplicates the 1176 “all-buttons” mode
  • LED gain reduction / output meter
  • Added 2:1 ratio for gentle compression
  • Switchable 100hz sidechain filer
  • Ability to stereo link two units
  • Works on +/-16v (500-series) or +/-24v (51x Alliance) power rails
  • Option for DOA or IC opamps


  • £30 for PCB set
A note on output transformers from Ed Anderson: “a lot of good options for output transformers if there is a pinout for LL1517 and a cutout for API 2503 size… cinemag, jensen, sowter all have catalog offerings that will fit that cutout. then there’s the 2503 from classicapi, the mini 1166 from hairball, and soon the same b11148 output used in the 1176 rev F will be available for peter purpose’s la3a 500 module — that should fit this PCB and have the original 1176 flavor.”

Additional Info: