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VLB525 compressor

VLB525 compressor plugin

Classic FET compressor plugin

  • Authentic hardware circuit / non-linear components emulation
  • Peak detecting feedback compressor / limiter
  • Threshold and make-up level
  • Ceiling adjusts compression and compensates the level
  • Gain reduction VU meter
  • Compressor mode (2:1 ratio)
  • Limiter mode (20:1 ratio)
  • Off mode: signal goes through the output opamp and transformer directly without compression
  • 4 release times: 0.1, 0.5, 2.0, 2.5 sec
  • De-Ess function
  • Adjustable attack
  • Mono or stereo, with adjustable stereo link
  • Parallel compression mix control
  • Adjustable internal simulation level
  • Optional noise floor and hum modeling
  • Retina displays compatible

A piece of history

Classic studio gear

The 525 compressor first appeared in the early 70's. It was integrated as a 500 module in famous american recording consoles. Over the years the 525 has become a favourite of many engineers in the recording industry, contributing its sound in numerous classic recordings.

The 525 is a character compressor that adds thickness and warmth to the signal. It is favoured on guitars, vocals, drums and bass. VLB525 further extends the hardware versatility with an adjustable attack time, and stereo link for stereo tracks or busses.

Classic mixing console

“I'm blown away by the stellar sonic quality and accuracy of this plugin. You guys have created the very first, in my opinion, API® emulation plugin capturing the real API® sound.”

- Koen Heldens

Beyonce, Rhianna, Jennifer Lopez

Circuit simulation

The real sound

VLB525 plugin carefully simulates the electronic circuit of the hardware, including the non-linear parts such as audio transformers, discrete opamps, FET transistor... All these components have a great impact on the resulting sound.

This precise simulation reproduces all the sonic characteristics and the subtle coloration from the simulated hardware.

Ceiling parameter

Easy compression level adjustment

The "ceiling" parameter increases the threshold and compensates the makeup level to keep a constant output level. The dynamics can be changed on the fly without altering the in / out settings.

  • 0: no compression or level compensation
  • ...
  • 20: maximum compression and makeup level
Ceiling parameter



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Audio Units
* AAX for Pro Tools 11 or 10.3.6 only

API is a registered trademark of Automated Process, Inc. and is not affiliated with LSR audio.
Copyright 2015. All rights reserved. Emmanuel Dubecq.