API 2500 - 3 Overview

50
th
Anniversary 2500 Bus Compressor API
8
3.0 Overview
The 50th Anniversary Edition of the API 2500 Stereo Bus Compressor provides a comprehensive suite
of controls:
• THRESH (Threshold): The level at which compression begins (+20dBu to -20dBu)
• Threshold LED: Indicates when the input audio crosses the selected threshold level
• RATIO: The amount of compression applied after threshold
o 1.5:1, 2:1, 3:1, 4:1, 6:1, 10:1, and ∞:1
• ATTACK: The time it takes for the compressor to respond
o .03, .1, .3, 1, 3, 10, and 30ms
• RELEASE: The time it takes the compressor to return to unity gain
o Fixed Times: .05, .1, .2, .5 , 1, and 2 seconds
o Variable: 50ms to 3 seconds
• KNEE: Sets the characteristic of the response curve at the onset of compression
o HARD: Aggressive onset of compression
o MED (Medium): Moderate onset of compression
o SOFT: Smooth onset of compression
• THRUST
®
: Activates the patented circuit that inserts a filter before the RMS detector
o LOUD: Gradual, 10dB/decade filter
o MED: Slight low-frequency attenuation and a slight high-frequency boost
o NORM (Normal): THRUST
®
filter not applied to side chain (flat)
• TYPE: Selects detection path routing
o NEW: feed-forward detection path
o OLD: feedback detection path
• L/R LINK: Sets the percentage of Left/Right control voltage link
o IND (Independent): Channels operate independently of each other or
o Percent: 50, 60, 70, 80, 90 or 100% linkage between channels
• SHAPE: Sets the speed of the Left/Right control voltage link
o FAST: Peak acting: RMS control voltage influence attenuated
o SLOW: RMS acting: peak control voltage influence attenuated
o Both: Both peak and RMS link control voltage influence attenuated
• MANUAL make-up GAIN: Selects MANUAL or automatic make-up gain
• GAIN: MANUAL make-up gain control (0dB to +24dB of output gain when MANUAL is engaged)