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Everything In Music - Since 1958
Everything In Music - Since 1958

API 550A Discrete 3 Band EQ

Out of Stock
Original price $1,195.00
Original price $1,195.00 - Original price $1,195.00
Original price $1,195.00
Current price $1,135.25
$1,135.25 - $1,135.25
Current price $1,135.25
About Inventory Status


Questions?
Call or text us at 301-946-8808.

In stock: It is in stock and available to ship or pickup. Apparel must be shipped from another location and is not available for in-store pickup. We can usually ship or have these items available for pickup by the next business day if they don't require inspection, special handling, or setup. Our pickup location is 11151 Veirs Mill Rd. Silver Spring, MD 20902.

📆 Preorder: It is on the way to our warehouse. We can't predict when preorder items will arrive due to current supply chain issues. If you place an order for one of these items someone will contact you to estimate the delivery date.

Out of stock: We don't currently have it available but you're not out of luck yet. We still may be able to get it. If you order one of these items we will contact you with an estimated fulfillment date. You have the option to cancel the order if you change your mind.

Special order: The item is so special that it needs to be custom ordered for you. Some of these items are works of art and have to be made individually. Orders for special order items must be prepaid and we cannot accept cancellations or refunds.

█ Sold out: We don't think we can get this item because it was either discontinued by the manufacturer or was limited in quantity. If you want or need this item call or text us. Sometimes we can help you track down the item through other sources or help you find something similar.

About Item Conditions


Questions?
Call or text us at 301-946-8808.

New: The item is brand new as received from the manufacturer with a full manufacturer warranty. Instruments such as guitars, snare drums, drum kits, brass and woodwind instruments may be opened for photography and quality control inspection and may not be in a factory sealed box.

Mint or Open Box: The item may have been opened and tested but has been repackaged. The original packaging may have superficial issues but the item itself and any originally included accessories are in perfect, like new condition.

Display Model: These items are so cool that we put them on display in our legendary shop. The condition is brand new as received from the manufacturer with manufacturer warranty. Rest assured, these items undergo a very careful inspection before shipping.

Demo: These items have been on our sales floor for demo purposes and will likely show signs of use. The original packaging may no longer be included, but you can be assured that you are receiving an awesome item and an awesome price.

Used: The item is used. These item may have varying degrees of wear. Please read the description for information about the condition of the item. Used items do not carry a warranty.

B or C Stock: Factory refurbished. These items were purchased from the manufacturer in a refurbished condition. They will show some cosmetic issues, but nothing that would impact performance. Being that these are sealed from the manufacturer, we generally do not open these to photograph the cosmetic issues. They are guaranteed to work and may have a limited warranty or you may purchase an extended warranty in some cases. Please see the listing description for item specific information.


Get A Standard Equalizer With The API 550A Discrete 3 Band EQ

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 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 push button 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.

  • 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

SPECIFICATIONS:

  • Input Impedance: 66 k ohm high level 17 k ohm low level
  • Output Impedance: Less than 85Ω (transformer isolated)
  • Nominal Operating Level: –15 dBm to +12 dBm
  • Insertion Loss: None (bridging)
  • Frequency Response, Unequalized: ±0.5 dB 30 Hz to 20 kHz
  • Noise: Unequalized, output noise of –90 dBm, high level strapping and –98 dBm, low level strapping, 20 Hz to 20 kHz unweighted
  • Distortion: .05% THD max, 30 Hz to 20 kHz @ +4 dBm .07% THD max, 30 Hz to 20 kHz @ +18 dBm
  • Clipping Level (3% THD): +30 dBm
  • Power Requirement: ±15 volts to ±18 volts @ 70 ma
  • Controls: Dual Concentric Rotary: LF select: 30, 40, 50, 100, 200, 300, 400 Hz and stepped degree of equalization –12dB to +12 dB
  • Dual Concentric Rotary: MF select: 200, 400, 600, 800, 1500, 3000, 5000 Hz and stepped degree of equalization –12dB to +12 dB
  • Dual Concentric Rotary: HF select: 2500, 5000, 7000, 10,000, 12,500, 15,000, 20,000 Hz and stepped degree of equalization –12 dB to + 12 dB. All equalization is in steps of 2, 4, 6, 9 and 12 dB either plus or minus
  • Toggle Switch: 50 Hz to 15 kHz band-pass filter In or out. Push Button: LF range Peak or Shelf. Push Button: HF range Peak or Shelf. Push Button: Equalization In or Out. Tally light when In
  • Connector: 30 pin PC connector supplied
  • Size: 1.5 X 5.25 X 7.75 inches
  • Size (Boxed for Shipping): 4.5 X 6.25 X 10.25 inches
  • Actual Weight: 2 lbs.
  • Shipping Weight: 2.53 lbs.

Manufacturer: Automated Processes Inc
Model: 550A
SKU: I302013-N-0-WHXB


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