Serpent SB4001 Stereo Buss Compressor – 500 Series

95 out of 100. Incorporating 10+ ratings and reviews.

Gearank High Notes

Gearank Recommendation

The Serpent SB4001 appeared on our recommended list for 500 Series Compressors in December 2020 where it remained until November 2022 when it was out-ranked by the WesAudio _DIONE.

Rating Source Highlights

WebsiteSource*Rating Value
Sound On SoundMatt Houghton98/100
TapeOpGarrett Haines97/100
*Displayed values are prior to the Gearank Algorithm’s adjustments it makes when evaluating the source.


Inspired by the SSL G-Series bus compressor, the Serpent SB4001 is hailed as the company’s evolution of SSL’s design.

Featuring Quad VCAs, 12 attack options, 5 fixed release options and a VAR mode that modernizes the original by tailoring the release with potentiometer.

A “grind” switch enables some tube-style harmonic saturation to your track.


  • Controls:Threshold, Ratio, Attack, Release, Blend, Gain, Filters, Variable Release
  • Input/Output Impedance: Not specified by manufacturer
  • Maximum Input Levels/Output Levels: +28dBu.
  • Attack: 0.1, 0.3, 1, 3, 5, 10, 15, 20, 25, 30, 40 and 50 milliseconds
  • Release: 0.3, 0.6 and 1.2 seconds, Variable release setting
  • Ratio: 1.5:1, 2:1, 4:1, 6:1, 8:1 and 10:1
  • Threshold: -20dB to +20dB