Specs

Center Frequency Selector,
7 selections on each band.
+/- 12dB Boost/Cut Stepped
Filter Control on each band
High and Low Frequency Peak/
Shelf positive action Military
Grade toggle switches
This Graph shows the “Propor-
tional Q” characteristics of the
550B Filter, from 0 to +12 dB of
Boost.
API Custom Solid Aluminum
Knobs
Fits API 2 slot, 4 slot, and 10
slot racks
Silent IN/OUT Switch
550b Features
Front Panel
Connector Pinout
Rear View
550b Specifications
Number of Bands: Four
Filter Type: “Low” and “High” bands are Peak/Shelf
switchable. Low-Mid and Mid-High are peaking type
Filter Frequency Centers:
Low: 30, 40, 50, 100, 200, 300, 400Hz
Low-Mid: 75, 150, 180, 240, 500, 700, 1Khz
Mid-High: 800, 1.5K, 3K, 5K, 8K, 10K, 12.5K
High: 2.5K, 5K, 7K, 10K, 12.5K, 15K, 20K
Filter Boost/Cut: +/- 12dB
Filter Slope: 12dB per Octave
Input Impedance: 18.5K +4 in, 7.5K -2 in
Output Impedance: Less than 75 Ohms
Nominal Levels: -15 to +15dBu
Clipping Level: +30dBu @ +/- 16V
Frequency Response: +0, -.3, 30 to 20kHz
Noise: Actual, unw noise, <-98 dBu, 20-20kHz
Distortion: .07% max, @ +18dBu Output
Connectors: 15 position .156 sp edge connector
Size: 1.50” X 5.25” X 6” Deep
Shipping/Actual Weight: 3lbs./2.5lbs.
Power Consumption: ±12/18 Volts/DC,@40 ma.
Rack Frame and Power Supply Options: Fits
500HPR (2 slot, internal power supply), 500-6B
“Lunchbox” (6 slot with internal power supply),
500VPR (10 slot and requires API 200PS Power
Supply, API Legacy Consoles and vintage API
Classic Consoles.
Mounting Frame and Power Supply Options
500H
2 Slot
frame with
internal power supply
500-6B
6 slot
“Lunchbox”
Frame with internal
Power Supply
500V
10 Slot
Frame
L200PS
Power Supply
Represented by:8301
8301 Patuxent Range Rd.
Jessup, MD 20794
Phone: (
301) 776-7879
Fax: (
301) 776-8117
Website: www.apiaudio.com