The bx_opto Pedal is a slimmed-down version of the bx_opto. It provides a great way to get that charismatic compression of the bx_opto with a simpler interface, lower price tag, and guitar pedal feel. After meticulously modeling the light-dependent circuits of several optical compressors, the bx_opto has amalgamated into a beastly little dynamics processor, teeming with character and spitting out sounds like no analog optical compressor can do. 

In addition to providing tone-laden compression, the bx_opto Pedal doubles as a gain pedal. By dialing-in the Density and Level Trim controls, you can add that little extra taste of gain and color that’s needed.

Most optical compressors are appreciated for their musical, program dependent character produced by the light dependent circuitry of the sidechain. They allow users the ability to adjust the effect of this character by introducing a separate resistance circuit that gives some control over the compression envelope.

Brainworx decided to take a different approach to adjusting this compression envelope when modeling the bx_opto and bx_opto Pedal. The modeled physical constant of the Light Dependent Resistor (LDR) was influenced by those of very real compressors, but there is no separate envelope circuit. Rather, the constant is directly manipulated by the ‘Speed’ parameter of the plugin. This introduces a whole different approach to sonic character that is impossible to replicate with a ‘real-world’ optical compressor.


  • The same optical compression circuit as the bx_opto
  • All in one sidechain input/makeup gain, ‘Density’
  • ‘Speed’ knob controls the modeled physical constant of Light Dependent Resistor, creating unique transient response
  • Output trim prevents overdriven signal from clipping
  • Guitar-pedal style power button

Audio Examples

Customer Reviews

  • Yep it's an opto

    by Nick F
    Sounds like a real-life opto guitar pedal compressor I used to own. Clever. A great option for electric guitar that you're processing in-the-box or reamping. I would recommend the full version for… Read More
  • it's pretty cool

    by emu
    I think I got this free, so maybe I don't appreciate it as much as I would if I paid. It actually put me off from Plugin Alliance for a while because I really liked the idea of the plugin but I… Read More
  • bx_opto Pedal

    by DmitryMOR
    Well in exceptional cases
  • comp-etent

    by J
    I,m not that big on pedals virtual or other but if required I am happy to use this in front .
    It can be used in other ways quite convincingly, for thought that don't have virtual models of… Read More
  • Buen Plugin

    by Mike Herrera
    Me parece interesante no lo uso demasiado pero al utilizarlo da un resultado magnifico.


Supported Plugin Formats
AAX DSP, AAX Native, AU, AAX AudioSuite, VST2, VST3

Supported Operating Systems
MacOS 10.9 through 10.14
Windows 7 through 10

Intel CPU only (minimum 2 GHz recommended)

Intel-compatible CPU with SSE2 instruction set (Pentium 4 compatible or higher; minimum 2 GHz recommended)

System Requirements
Display resolution: 1440 × 900px or 1280 × 960px or higher
Memory: 2 GB RAM


With the Installation Manager, you can select, download and install just the Plugin Alliance products and formats you need for your system.