Few equalizers enjoy the respect and admiration of the coveted API 550A.
Designed by the now-legendary Saul Walker in the late '60s, the
discrete 550A was first used as a modular OEM equalizer. As the industry
rapidly embraced the sonic quality of the 550A, it quickly found its
way into many custom console designs by Frank DeMedio and other leading
engineers. Many of these consoles are still in use today.
Forty years later, the 550A remains the standard against which other EQs
are measured, and it has played a major role in the recording industry
for decades. Still copied but never duplicated, the 550A became API's
standard channel module EQ when the company began manufacturing consoles
in 1971. With virtually all existing units spoken for, popular demand
for this EQ resulted in API finally resuming production in 2004.
The 550A provides reciprocal equalization at 21 points in 7 steps of
boost to a maximum of 12dB of gain at each point. The fifteen
equalization points are divided into three overlapping ranges. The high
and low frequency ranges are individually selectable as either peaking
or shelving, and a band-pass filter may be inserted independently of all
other selected equalization settings. Frequency ranges and boost/cut
are selected by three dual-concentric switches, and a pushbutton "in"
switch allows the EQ to be silently introduced to the signal path. A
small toggle switch is used to insert the band-pass filter into the
550A.
The combination of Walker's incomparable 2520 op amp and his
"Proportional Q" circuitry gives the 550A user an uncomplicated way to
generate acoustically superior equalization.
With the long-awaited reissue of this unit, an EQ that has had such a
part in the history of recording is continuing to make history in
today's music.
Features
3 bands of classic API equalization
Each band offers 7 API selected frequency centers
Reciprocal and repeatable filtering
Maximum 12 dB of boost/cut per band
EQ Band 1 and 3 offer shelf/peak switching
"Proportional Q" narrows filter Q at extremes
Traditional API fully discrete circuit design
High headroom +30 dB clip level
2 Year Warranty (labor) 5 Year Warranty (parts)
We double the standard API one year warranty (parts and labor) on this item.
