API Audio THE BOX - Manual (Page 49)

API “The BOX” Operator’s Manual
49
6.0 527 Compressors
“The BOX” is equipped with two API 527 compressor/limiters that are located above the
master section of the console. These compressors are assigned to the program bus by default
for mixing, but can be routed to the input channels while recording.
The API 527 Compressor takes it's place alongside the family of API VCA based compressors,
the 225L and the 2500 Stereo Bus Compressor. Anyone familiar with those units will
immediately be at home with the 527.
Features common to the line like "feed forward" (NEW) and "feed back" (OLD) gain reduction
methods, selectable on the front panel, provide a choice of "that old way", or "the new way"
of compression, for the highest level of flexibility in signal gain control. The "old way" or
Feed-Back method is what most of the classic compressors used for the gain control circuit.
The "new way" gain reduction is more typical of the newer VCA type compressors that rely on
RMS detectors for the gain control voltage.
There is a "SOFT"/"HARD" KNEE switch for an "over-easy" type compression resulting in a
very natural, uncompressed sound or a typical sharp knee type that lends itself to a much
more severe limiting effect.
The patented THRUST ® function can be switched in and out as well, applying a high pass
filter before the RMS detector circuit that preserves that punchy bottom end.
The output level remains fairly constant regardless of the threshold or ratio control, much like
the "more/less" Ceiling control on the API 525 Compressor. This allows for live adjustments
without any noticeable gain changes in the program level.
The 527 Compressor makes use of the 2520 discrete op-amps and exhibits the reliability,
long life, and signature sound, which are characteristic of API products.