API 550 recreates the classic 550A and 550B equalisers from the late 1960s, developed in close collaboration with API.

Its hallmark is proportional Q, which varies with gain: boosts sound focused and musical, cuts allow natural tone shaping, and boost and cut behave symmetrically. With three bands of five selectable frequencies each, the 550A suits general sweetening, while the 550B with four overlapping bands takes a surgical, problem-solving approach. You can, for example, separate two layered guitars purely with EQ, and on individual tracks, buses or full masters the 550 delivers musical transparency.

Features

• Two classic EQs: 550A and 550B
• Proportional Q with symmetrical boost and cut
• 550A: 3 bands with 5 selectable frequencies each, plus 50 Hz – 15 kHz filter
• 550B: 4 overlapping bands with multi-octave ranges
• High and low bands switch between peak and shelving
• Switchable analog distortion and hiss, phase switch, output trim and metering

Technical details

• Operating systems: Windows, macOS
• Plug-in formats: VST3, Audio Unit (macOS only), AAX
• Architecture: 64 bit
• Licensing: licence key, machine-bound or USB flash drive (via Waves Central)

System requirements

• macOS 14 Sonoma, 15 Sequoia, 26 Tahoe or 27 Golden Gate (Apple silicon or Intel)
• Windows 10 64-bit (version 22H2) or Windows 11 (Intel or AMD, x64)
• 16 GB RAM
• 30 GB free disk space on the system drive

The licence is registered with the manufacturer at https://www.waves.com/downloads/central. You will receive your serial number and the download link by e-mail immediately after purchase.