API 527 - Compression Type Selection; OLD: Feed-Back Compression; NEW: Feed-Forward Compression

API 527 Compressor
COMPRESSION TYPE
The 527 Compressor can be set to operate in two circuit
topologies:
· OLD: Feed-Back topology: The RMS detector
receives the signal from after the VCA
· NEW: Feed-Forward topology: The RMS detector
receives the signal from before the VCA
The compressor circuit topology is selected using the TYPE
switch.
TYPE
LINK
KNEE
THRUST
R
METER
VU
GR
IN
NEW
OLD
HARD
SOFT
IN
IN
In a feed-back compressor, the RMS detector gets its signal from the
output of the gain reduction device (VCA). This is how older API 525,
1176 type, and 660 type compressors work. This yields a smoother,
softer, more transparent sound
.
OLD: Feed-Back Compression
IN
OUT
THRESHOLD, ATTACK,
RATIO, RELEASE,
LINK CONTROLS
RMS DET
THRUST
FILTER
"OLD" or FEED BACK type COMPRESSION
2 VCA's
PER
CHANNEL
2510
2520
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