529 Stereo Compressor

The API 529 is a high-performance stereo bus compressor that combines the legendary sound of API's 2500 bus compressor with innovative features, all housed within a double-wide 500 series module. Based on the same discrete circuit path that has made the 2500 an industry standard, the 529 delivers the classic API punch, glue, and analog warmth that engineers prize for mix bus and sub-group processing. It is designed to add cohesion and energy to stereo mixes, drum busses, and instrumental groups, making everything sound more powerful and finished.

The 529 inherits the core feature set of its famous predecessor, including API's patented "Thrust" circuit for preserving low-end punch and a switchable "New/Old" selector that toggles between modern feed-forward and classic feedback compression styles. It offers full control over Threshold, Ratio, Attack, and Release, allowing for a wide range of dynamic shaping. A unique and powerful addition to the 529 is an internal sidechain high-pass filter, which can be engaged to make the compressor less reactive to heavy bass frequencies, preventing pumping artifacts. The most significant innovation, however, is the Auto-Makeup Gain feature, which automatically compensates the output level as the threshold and ratio are adjusted, allowing the user to focus on the character of the compression without being distracted by level changes. The unit features two 10-segment analog-style VU meters for clear visual feedback of gain reduction.

Features

• Stereo Bus Compressor based on the legendary API 2500.
• Double-wide 500 Series module format.
• Classic API discrete circuit path with 2510 and 2520 Op-amps.
• Patented "Thrust" circuit for frequency-dependent sidechain control.
• Switchable "New" (Feed-forward) and "Old" (Feedback) compression types.
• Auto-makeup gain for level-matched A/B comparisons.
• Internal sidechain with selectable high-pass filter.
• Linkable for stereo operation with true RMS power summing.
• Two 10-segment analog-style VU meters for gain reduction.