Manufacturer Description: The API 550 EQ played a major part in the history of music recording in the USA during the 60's and 70's. Originally conceived for use in API's consoles, this latest 550 "B" version is a continuation of the original 1967 550 through the 550A with one additional filter band and several new frequencies. Incorporating API's exclusive circuitry and proprietary components (such as the legendary API 2520 op-amp), the 550B artfully blends the past with the present. So many hit records still depend on the unique 550 sound, that the 550B will be an invaluable tool you will turn to again and again. The API 550B—unlike any other you will ever use.

    * 4 bands of our famous sounding equalization
    * Each band offers 7 API selected frequency centers
    * Reciprocal and repeatable filtering
    * 12 dB of boost/cut per band
    * EQ Band 1 and 4 offer shelf/peak switching
    * "Proportional Q" narrows filter Q at extremes
    * Traditional API fully discrete circuit design
    * High headroom +30 dB clip level
    * Re-issue of 1967 API 550 EQ with an extra band

Many EQ's today offer a huge assortment of complex features, but the API 550B provides exactly the right number of controls to the professional engineer. Deceptively simple at first glance, the 550B's four EQ bands are overlapped significantly to aid in dual roles as problem solver and sweetening device. Each band offers 7 switchable filter frequencies spanning 4 to 5 octaves, selected through experience by a "who's who" list of the industry's most proficient engineers. This re-issue design has been taken from the original blue prints and spec control drawings from the API archives.