Harman 266xs Air Compressor User Manual


 
Compressor ATTACK and RELEASE Control
The ATTACK control sets the amount of time it takes the 266xs to begin compressing a signal
once the detector has sensed a signal above threshold. The ATTACK range is from FAST (for a
tighter and more noticeable compression effect with very little overshoot) to SLOW (for more
delayed, gradual compression). A very fast ATTACK setting will cause the 266xs to act like a
peak limiter even though RMS detection circuitry is used. Slower ATTACK settings cause the
266xs to act like an RMS or averaging detecting compressor/limiter.
The RELEASE control sets how fast the compression circuit returns the input to its original
level. The RELEASE rate is from FAST (where compression follows the envelope of the program
material very tightly) to SLOW (for very smooth compression).
There is no absolute right way to set the ATTACK and RELEASE controls. However, in general,
you will want them set slow enough to avoid pumping or breathing sounds caused when
background sounds are audibly modulated by the dominant signal energy, yet the release must
be fast enough to avoid suppression of the desired signal after a sudden transient or loud
note has decayed. For low frequency tones (e.g., bass guitar), set RELEASE and ATTACK to
2:00 or slower.
NOTE: ATTACK and RELEASE controls operate together and in conjunction with the RATIO
control. Changing one control may necessitate changing another setting.
AUTO Switch
This switch overrides both the ATTACK and RELEASE controls and enables preset program-
dependent attack and release times. These times are derived from the input signal and con-
tinuously change to match its dynamics. Enabling this AUTO Function duplicates the “classic
dbx sound” of the 266xs forerunners which have become standards in the industry.
Expander/Gate THRESHOLD Control and LEDs (BELOW/ABOVE)
NOTE: The Expander/Gate is off when the Expander/Gate THRESHOLD is set to OFF.
Adjusting this control sets the level at which the gate will open and allow the signal at the
input to pass through to the output. Turning the knob fully counterclockwise (to OFF) allows
the gate to pass all signals unattenuated, effectively bypassing the gate. Turning the knob
fully clockwise causes the gate to attenuate input signals below +15dBu. The depth of attenu-
ation depends on the setting of the Expander/Gate RATIO control.
The two Expander/Gate LEDs indicate the relationship of the input signal level to the thresh-
old setting. The red LED lights when the signal is BELOW threshold, the green LED lights when
the signal is ABOVE threshold.
Section 2
Getting Started
7
dbx 266xs