API 525 Compressor – 500 Series
The API 525 is a faithful reissue of the original 1970s API feedback-style compressor/limiter, delivering classic character and punch in the versatile 500 Series format. Inspired by the legendary Urei 1176, the 525 offers a peak-detecting, feedback-based compression circuit that is ideal for everything from vocals and drums to guitars and bass — with that unmistakable vintage API tone.
At the heart of the 525 is its unique “Ceiling” control, which simultaneously adjusts threshold and makeup gain. This design allows you to dial in the exact amount of compression while maintaining a consistent output level, simplifying workflow and enhancing dynamic control. Additionally, the unit features independent Threshold and Output controls for more traditional operation.
The 525 includes four selectable release time settings, a dedicated De-Ess mode for taming harsh sibilance, and an analog VU meter for precise gain reduction monitoring. With its hardwire bypass switch, the compressor can be cleanly taken out of the signal path for quick A/B comparisons.
Built using API’s fully discrete analog circuitry and featuring active balanced input and output, the 525 delivers the sonic integrity, headroom, and warmth that has made API dynamics processors a studio standard for decades.
Key Features:
- Exact reissue of the original API 525 compressor from the early 1970s
- Peak-detecting feedback compressor/limiter circuit
- Unique “Ceiling” control adjusts threshold and makeup gain simultaneously
- Independent Threshold and Output level controls
- 4 selectable release time settings
- De-Ess function for vocal sibilance control
- Analog VU meter for gain reduction monitoring
- Hardwire bypass for clean A/B signal comparison
- Active balanced input and output
- Fully discrete analog design with classic API circuitry
- Fits standard 500 Series lunchbox or rack
The API 525 is a must-have for engineers seeking classic compression character with modern functionality. Whether used for subtle dynamics shaping or aggressive limiting, the 525 delivers the punch, warmth, and reliability that only API can offer.