Einkanaliger Kompressor/Limiter für das 500 Serie-Format
The API 527 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" 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 Threshold control sets the initial operating parameter. The 527 can be
operated with signal input levels from +10 dBu to -20 dBu.
The 527 features an Output fader control that ranges from minus infinity to
+10dB, and output capability is +28 dBu through our 2520 discrete amplifier and
a large API output transformer. 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 patented THRUST® function can be switched in and out via the front panel
as well, applying a high pass filter before the RMS detector circuit that
preserves that punchy bottom end.
Attack and Release are fully adjustable on the 527. Release time can be
adjusted by rotating the inner concentric RELEASE knob. Release time constants:
.3 sec to 3 sec. Attack time is adjusted on the outer concentric ATTACK knob,
which ranges from 1 millisecond to 25 milliseconds.
The 527 is designed for individual channel use or, through the use of the
LINK switch, two units can be combined for Stereo applications via a motherboard
The 527 Compressor/Limiter makes use of the 2510 and 2520 Discrete Op-amps
and exhibits the reliability, long life, and signature sound which are
characteristic of API products.
? Audio circuit uses the 2510 and 2520
Discrete Op Amps with transformer output
variable detented Threshold control
? Continuously variable
detented Attack and Release controls
variable detented Ratio control
? Output Fader level
? 10 segment VU/Gain Reduction meter with selector
? Overload LED
? "Link" switch
for multiple unit interdependent compression linking
"New"/"Old" switch for feed-forward or feed-back compression
? "Hard"/"Soft" compression curve knee switch
Patented "Thrust" switch for frequency dependent side chain control
? "IN" switch with hard relay bypass when in the "Out"