The GLA-2A was developed for audio engineers, producers, and musicians seeking the musicality and smoothness of the legendary American tube-based optical compressors that shaped the history of professional recording.
Inspired by the classic architecture that became a benchmark in countless studios worldwide, the GLA-2A delivers extremely natural compression, preserving the performance's full dynamic range while adding warmth, depth, and harmonic richness to the signal.
Its circuitry combines the characteristic response of optical compression with the sonic character of tubes, yielding transparent results when needed and an incredibly musical sound when pushed to higher levels of gain reduction.
Whether used on vocals, bass, electric or acoustic guitars, keyboards, or various other instruments, the GLA-2A offers elegant compression that enhances the performance without compromising its natural feel.
Unlike compressors with extremely fast, aggressive responses, the GLA-2A operates progressively, naturally tracking the music's dynamics.
This characteristic makes the compressor virtually imperceptible during processing, preserving the expressiveness of the performance while smoothing out peaks in an incredibly gentle manner.
The result is a full-bodied, three-dimensional, and pleasing sound, making the GLA-2A an excellent choice for both tracking and mixing.
One of the GLA-2A's key features is its Attack selector, designed to further expand the unit's versatility.
Users can choose between three distinct attack behaviors, adapting the compressor to a wide range of applications.
Original
Replicates the classic behavior of the optical architecture renowned in professional studios, offering the natural response that made this type of compressor a global standard.
Slow
Increases the attack time, allowing more transients to pass through before compression kicks in.
Ideal for preserving the impact of drums, acoustic guitars, piano, and highly dynamic instruments, while maintaining a more open and natural feel.
Fast
Reduces attack time, allowing for greater control over fast transients.
Excellent for aggressive vocals, electric bass, guitars, percussion, and any application requiring tighter dynamic control.
The GLA-2A utilizes a carefully engineered optical circuit combined with a solid-state sidechain stage, preserving the musical character that made this type of compressor a global standard.
The interaction between circuit elements produces extremely smooth compression.
The result is a unit capable of controlling dynamics without draining the life from the performance.
Each unit is hand-assembled using carefully selected electronic components and undergoes rigorous functional testing before leaving Greenbox Pro Audio.
The result is robust, reliable equipment built for years of professional studio use.
Peak Reduction
Controls the amount of compression applied to the signal.
Gain
Allows for output level compensation after compression.
Compress / Limit
Selects between gentle compression and more intense limiting, expanding the unit's versatility.
Attack
Selector with three distinct attack curves:
• Original
• Slow
• Fast
VU Meter
Analog meter for precise monitoring of gain reduction during processing. Applications
• Vocals
• Backing vocals
• Electric bass
• Upright bass
• Acoustic guitar
• Clean electric guitar
• Piano
• Strings
• Brass
• Overheads
• Room microphones
• Tube optical compressor
• Circuitry with architecture inspired by American classics
• Selectable attack (Original, Slow, and Fast)
• Compress and Limit modes
• Selected electronic components
• 100% made in Brazil
• Heavy-duty metal chassis
• Low-noise power supply
• Excellent headroom
• Low noise floor
