5
9.
LINE LEVEL:
Used to set the nominal input levels for the stereo line input. Adjust for a nominal level of
0 dBu for best results. If the line input is not used, this control should be turned off to remove any line pre-amp
noise from the signal path.
10.
BALANCE:
Use this control to balance the stereo line signal in the left and right stereo field. If the line input is
mono (no right input jack connected) this control becomes a pan control.
11.
INSERT ON:
The pre-amp signals are routed through the rear panel insert jacks (TRS) before continuing to the
first parametric filter. This switch activates the inserts; an LED shows the status. The insert jacks will always
have the pre-amp signals at the send (tip) contact irregardless of the setting of this switch, letting them be used
as “dry” outputs if one is required.
12.
PARAMETRIC LEVEL:
Adjusts the amount of cut or boost applied to the signal at the frequency specified by the
frequency control and the bandwidth set by the octave control. The maximum range is +/-15 dB. Most uses will
require a cut. Both parametric equalizers are fully stereo.
13.
PARAMETRIC FREQUENCY:
Sets the center frequency of the parametric filter. The range of adjustment is
wide: 40 Hz to 15 kHz. The two filters’ adjustment ranges are identical.
14.
OCTAVE:
Adjusts the bandwidth (Q) of the parametric filter. It is variable from 2 octaves (wide bandwidth,
broad tuning) to 1/6 octave (narrow bandwidth, critical tuning) as measured at the state-variable filter’s output.
Narrow bandwidth is usually used to notch out (cut) problematic feedback frequencies; wide bandwidth can be
used to boost or to cut.
15.
PARAMETRIC ON:
To activate the parametric filter, press this switch. An LED will indicate that it is on line.
The second filter’s enable switch functions even when it is used in the side-chain mode to enable side-chain
processing.
16.
PARAMETRIC TO SIDE-CHAIN:
This switch allows the second parametric filter to be inserted into the side-
chain of the dynamics processor (after the side-chain insert jack return). This provides the ability to either
remove frequencies from the detector path (making the dynamic’s circuitry LESS sensitive to that part of the
audio information), or to boost them (causing the detector to be DOMINATED by those frequencies). Uses would
include de-essing (a side-chain boost at high frequencies) to help reduce sibilance, or the removal of rumble
modulation (a side-chain cut at low frequencies) which can cause pumping and breathing. It can also be set so
that the compressor will only respond to certain frequencies to even out the effects of resonance (primarily in
guitars and synths) that cause some notes to be much louder than others. Since the external side-chain input is
routed through this filter when this switch is engaged, it can be used to bandwidth limit a keying signal.
17.
EXTERNAL SIDE-CHAIN ON:
The side-chain is another name for insert points in the input of the dynamic
section’s RMS rectifiers. Normally, the same audio signal is applied to the voltage controlled amplifier and its
detector, causing all processing to be controlled by the input, however there are instances when this is not what
is desired. If the control is to be given to another signal (to duck, for example), the input of the detector must
look at another input. A standard TRS insert jack is provided on the rear panel and is activated by this switch.
Any signal applied at the jack will not be seen unless the side-chain is enabled. This switch does not affect the
“parametric to side-chain” function which is always available. The external signal will be modified by the
parametric filter if it is active, however.
18.
EXPANDER THRESHOLD:
The expander is actually a downward expander that adds attenuation to the signal
as it decreases in level, following defined set points and curves. It behaves oppositely of compression. This
adjustment sets the level at which it begins operation. An LED indicates that this threshold has been crossed
and downward expansion has begun. If the input signal drops below the threshold’s set point, the expander
fades it out according to the slope (ratio) set by the ratio control. The soft knee design smoothes the transition
from off to active by dynamically shifting the slope through the transition point. The attack and release times are
preset for best response.
19.
EXPANDER RATIO:
The expander ratio is determined by dividing the input level by the output level. A ratio of
1:5 signifies that the output level has dropped five times as fast as the input. Ratios of 1:1.2 to 1:2 are typically
used to eliminate background noise and to dampen room reverberations. Higher ratios are used when gating is
required, and usually require lower thresholds to keep from cutting off the source too soon.
