225L
Compressor/Limiter
The API 225L Compressor/Limiter is ideal for all studio, live sound and broadcast applications.
Regardless of the threshold or ratio settings, the output level always remains at unity. This unique
feature allows real-time adjustments without changing the output level. Both "feed forward"
(new) and "feed back" (old) gain reduction methods are selectable on the front panel. There also
is a SOFT or HARD selector for either an "over easy" compression resulting in a very natural,
uncompressed sound or a typical sharp knee type that has a much more severe limiting effect.
The 225L is designed for individual channel use or two units can be combined for Stereo
applications via a rear access pin. The 225L also has a side-chain input for the detector amplifier.
As a custom option, two 225L Compressors can be linked together for stereo applications. A DC
control voltage link is available via an access pin on the rear of the unit. This modification
requires a switch and custom wiring and is available at extra cost.
The controls for the 225L Compressor/Limiter function as follows:
Features:
•
Threshold control from -20 to +10 dBu
•
Variable compression ratio from 0 to infinity
•
Fast, Medium and Slow Attack Times
•
Adjustable release time from 50ms to 3 seconds
•
"Old" or "New" sound
•
HARD or SOFT compression knee
•
Always at unity gain, regardless of settings
•
LED Gain Reduction meter
•
API 2510 and API 2520 op-amps
•
Transformer output to +28 dBu
The 225L Compressor is typically installed in the Lower 200 Slot.
ON (On/Off switch): Activates the module
•
A green LED indicator illuminates when engaged
THRESH (Threshold): Sets the activation threshold
•
-20dB to +10dB
RATIO: Sets compression ratio
•
0 to
∞
•
0: 1:1…no gain reduction
•
∞
:
∞
:1…hard limiting
REL (Release Time): Sets release time
•
60ms to 3 seconds
KNEE (HRD-SFT): Selects the “knee” of the onset of compression
•
HRD (Hard): Fast curve (more useful for limiting applications)
•
SFT (Soft): Slower curve (acts as an “over-easy” compressor)
AT (Attack Time): Selects attack time
•
F: Fast
•
M: Medium
•
S: Slow
