Beschreibung
API 550aDiscrete 3 Band EQFew 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.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. 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 levelTechnical Specifications: Input Impedance: 66 kΩ high level, 17 kΩ 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 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″ Deep Size (Boxed for Shipping): 4.5″ X 6.25″ X 10.25″ Actual Weight: 2 lbs. Shipping Weight: 2.53 lbs.
