Serpent Audio SA-3A LA3A Opto Compressor

Projects > Serpent Audio SA-3A LA3A Opto Compressor

The SA-3A is a dual channel replica of the UREI/Teletronix LA-3A optical compressor from Serpent Audio (formerly Shadow Audio). PCBs and kits consist of one channel + power supply, but two channels can be linked and built in a single 2RU case.

Notable Features:

  • Simplifies the complex wiring of the original for DIYers
  • Transformers:
    • Input: Cinemag (same as in Universal Audio’s reissues)
    • Interstage: Custom reproductions by Ed Anderson
    • Output: Ed Anderson
  • Accepts many modern transistors
  • All voltages and components are identical to the original LA-3A


  • $300 for stereo PCB and transformer bundle
  • $55 for stereo front panel
  • $20 for stereo matched transistors
  • $25 for power transformer

More info:


Comments are closed.