*Please note this item is pre-owned and may show signs of use. Please see photos.

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 5 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.

Product Specs

Condition:
Excellent (Used)
Brand
API
Model
550A
Categories
Equalizers, 500 Series

About The Seller

Alto Music
Joined Jul 2014
Middletown, NY, United States

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This product can be returned within 30 days of receipt.

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Alto Music does accept returns on unopened/unused products within 30 business days of the purchase date. If the product has been opened/used we may charge up to 50% restocking fee from your refund if the product/packaging is not returned in the exact listing condition. Alto Music does reserve the right to refuse any return that is opened/used and not in the same new condition as when originally shipped to the customer.

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Alto Music

Middletown, NY, United States
Joined: Jul 2014

Seller Achievements

API 550A Discrete 3-Band Equalizer
$1,099
+ Free Shipping