16
4.2 Compressor Section
Fig. 4.3: Control elements of the compressor section
6
The THRESHOLD control sets the threshold point for the compressor section. It has a range of -40 to
+20 dB. The Soft Knee characteristic is applied to the signal exceeding the threshold point by a
maximum of 10 dB. Above 10 dB, the signal would experience Hard Knee compression. The
THRESHOLD-LEDs show the actual state of the input signal relative to the THRESHOLD setting. The
IKA-Soft Knee range is indicated by the middle yellow LED.
7
The RATIO control determines the ratio between the input and output level for all signals exceeding
the threshold point by more than 10 dB. The control range can be adjusted from 1:1 to oo:1.
8
The ATTACK control determines the rate by which the compressor responds to the signal which
exceeds the threshold. This control can be adjusted from 1 to 150 milliseconds.
9
The RELEASE control determines the rate that the compressor returns to unity gain after falling below
the threshold level. This control can be adjusted from 0.05 to 5 seconds.
10
By activating the AUTO switch, the ATTACK and RELEASE controls are disabled and the attack and
release rates are automatically derived from the programme material. This function allows for unobtrusive
musical compression of signals or mixes with widely varying dynamics. Only if set to MANUAL will
the settings of the attack and release controls function.
11
The OUTPUT control allows for the increase or decrease of the output signal by a maximum of 20 dB.
Thus, a level loss due to the compression or limiting process can be compensated for.
+
Please note when using the THRESHOLD control of the Peak Limiter section, that the OUTPUT
control of the Compressor section precedes the Peak Limiter section. If the OUTPUT control is set too
high, this can result in continuous peak limiting (see item 19 THRESHOLD control).
12
When activated, the SC EXT switch severs the connection between the audio input and the sidechain
path, whilst at the same time allowing an external signal to be sourced at the SC RETURN jack on the
rear panel.
13
Using the SC MON switch will enable you to connect the sidechain control signal to the audio output,
whilst at the same time muting the audio input. This function provides you with the ability to monitor the
sidechain signal that is returned via inserted equalizers or other external processors. The SC MONITOR
function will assist you with tuning equalizer parameters for example.
+
Please note when the SC MON switch is engaged, the audio processing facility of the respective
channel is disabled. When this function is active, a visual indication will be provided by the switches
LED, which will blink.
14
The IN/OUT switch activates the relay and hence the corresponding channel. This switch acts as a so-
called hard-bypass relay, which means that when the switch is OUT or when the unit is disconnected
from the mains, the input jack is directly linked to the output jack. Normally, this switch is used to
perform a direct A/B comparison between the unprocessed and the compressed or limited signals.
4. CONTROLS
