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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

Product Specs

Condition:
Brand New (New)
Brand
API
Model
550A Discrete 500 Series 3 Band EQ
Categories
Equalizers, 500 Series

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About The Seller

Vintage King Audio
Joined Sep 2015
Ferndale, MI, United States

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Ships from Ferndale, MI, United States to:

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Free shipping with tracking to the continental United States unless otherwise noted. Alaska, Hawaii, and international shipments may incur additional charges.

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Return Policy

Return Window

This product can be returned within 30 days of receipt.

General Terms

Items must be returned in original, as-shipped condition with all original packaging and no signs of use. Buyer assumes responsibility for all return shipping costs unless the item was not received as described.

Refunds

Buyer receives a full refund in their original payment method less any shipping costs.

Special Conditions

We make returns easy

We do our best to help you choose the perfect gear, but if you don’t love it in the first 30 days after receipt, please contact customer service for a return authorization.

Contact customer service Monday-Friday from 10 AM and 6 PM Eastern Time. Email customerservice@vintageking.com or call 888.653.1184, and press 2. If outside the United States please call 1.248.591.9276.

Avoid Restocking Fees

Help us sustain our Easy Return policy. To reserve your right to return the gear within 30 days with no re-stocking fees please observe these steps upon receipt of item(s):

Keep all packaging in like-new condition. Open packaging gently and carefully.

- When opening package use scissors and try avoid tearing packaging.
- Take note of how components are packed.

Keep all items in new condition unless 100% sure you’re keeping the gear.

- Avoid scuffs and scratches in handling and rack mounting.
- We recommend rack mounting only after you’re certain you’re keeping the gear.
- If rack mounting, use plastic washers and beware of metal rack screws’ tendency to scratch rack-mount holes.

Include everything that came with your purchase. If equipment or accessories are damaged or missing, a re-stocking fee will apply upon return.

How to Return your Items

Domestic Returns:

- Contact Vintage King to obtain a Return Authorization (RA).
- Place a copy of the RA inside the package of the items for return.
- Write RA number anywhere on your airbill, not on the box or packaging.
- Returns must be complete including accessories and documentation with original packaging.
- You are responsible for return shipping costs including shipping insurance which is recommended to protect your items, as you are liable for items damaged during return shipment. Remember you own it until we receive it.
- Obtain a tracking number to provide proof of your return before the end of the 30-day grace period in order to avoid a re-stocking fee.

The following products are NOT returnable:
- Special Order Items - Items that are non-stocking and require special ordering
- Personal items - Items that require intimate contact with the body during use, including in-ear headphones and microphone windscreens
- Custom built cabling, mic input panels and stage boxes
- Software
- Computers
- Hard Drives
- Recording Master Tape
- Studio furniture, racks and chairs
- Items shipped via freight

We will inspect your return once it’s received. If you have met the above conditions and the items are all in like-new condition, you will get your choice of a full refund or credit on account.
- If any of the above conditions are not met, Vintage King reserves the right to charge a fee equal to our costs to return the item to like-new condition.
- NOTE: If you received Free Shipping on your order, the value of the uncharged shipping cost will be deducted from your refund or credit.

International Returns:

Important: In order to avoid unnecessary duties or taxes when returning your item(s), you MUST use the customs and shipping documents Vintage King provides along with your Return Authorization. Vintage King will refuse shipment of items when customer fails to use Vintage King provided customs and shipping documents or returns items without prior authorization. All costs are the sole responsibility of the customer.

- Contact Vintage King to obtain a Return Authorization (RA).
- Place a copy of the RA inside the package of the items for return.
- Write RA number anywhere on your airbill, not on the box or packaging.
- Returns must be complete including accessories and documentation with original packaging.
- You are responsible for return shipping costs including shipping insurance which is recommended to protect your items, as you are liable for items damaged during return shipment. Remember you own it until we receive it.
- Obtain a tracking number to provide proof of your return before the end of the 30-day grace period in order to avoid a re-stocking fee.

The following products are NOT returnable:
- Special orders
- Personal items (earphones, headphones, etc)
- Software
- Computers
- Hard Drives
- Tape
- Over-size or over-weight items

We will inspect your return once it’s received. If you have met the above conditions and the items are all in like-new condition, you will get your choice of a full refund or credit on account. If any of the above conditions are not met, Vintage King reserves the right to charge a fee equal to our costs to return the item to like-new condition. Note: we reserve the right to deny any return to any customer if there is any history of abusing the Vintage King return policy.

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Vintage King Audio

Ferndale, MI, United States
Joined: Sep 2015

Seller Achievements

API 550A Discrete 500 Series 3 Band EQ
$1,135.25
+ Free Shipping