Specifications
5
2. +48 V: Turns on the +48 V phantom power for mics that require it. Do not enable phantom power if an
unbalanced low impedance mic is used, since the mic could be damaged. The LED will light if phantom
power is present.
3. POLARITY: The polarity of the mic input can be reversed in the event that the signal is out of phase with either
the line or other signals. This can happen when miking the top and bottom of the soundboard of a piano, or both
sides of a speaker cabinet or a drum head.
4. PAD: If the input level is too hot, and the gain control cannot be turned down far enough to avoid distortion,
engage this switch. This attenuates the input signal by 20 dB. It reduces the level of the input stage to avoid pre-
amp clipping, which could occur when close miking loud sources.
5. MIC ON: Enables the XLR input. If the mic input is not used, it should be turned off. This will improve the signal-
to-noise ratio by removing all residual mic pre-amp noise from the signal path. This switch can also be thought
of as a mic mute, if the mic must be turned off temporarily when it is active. The LED will light when the mic
input is live.
6. LOW CUT FREQUENCY: The low-cut filter (on the mic input only) is adjustable from 10 Hz to 350 Hz, and is
always on line. To minimize its effect, set it fully CCW (10 Hz). Adjust this control to reduce the boom and thump
of proximity breath effects, stage rumble, and handling noise. It has a 12 dB per octave slope. This control is
before the insert point, so its adjustment will affect the “dry” signal throughout the unit.
7. GAIN: This control sets the gain of the mic pre-amp, and should be adjusted to provide a nominal signal level of
0 dBu at the “dry” output. This is the optimum level for the rest of the circuitry that follows. This control should be
adjusted by setting the output meter select switch to “pre-amp” and adjusting it for a 0 dB average level.
8. LINE INPUT: High impedance (200 k Ohms) 1/4" TRS balanced input for line level signals, including wireless
mics, guitars and synths. If used in an unbalanced configuration (ring grounded, tip signal) the input impedance
is 100 k Ohms. There is a parallel jack on the rear panel that is automatically disconnected when this jack is
used.
9. LINE LEVEL: Used to set the nominal input level for the line input (# 8). Adjust for a nominal level of 0 dBu for
the best signal-to-noise ratio (see # 7). 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. INSERT ON: The pre-amp signal is routed through the rear panel insert jack (TRS) before it continues to the
first parametric filter. This switch activates the insert; an LED shows its status. The insert jack will always have
the pre-amp signal at the send (tip) contact irregardless of the setting of this switch, letting it be used as a “dry”
output if one is required.
11. 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 range varies from an extreme 24 dB notch to
a 12 dB boost. Most uses will require a cut.
12. PARAMETRIC FREQUENCY: Sets the center frequency of the parametric filter. The range of adjustment for the
first filter is 40 Hz to 4 kHz. The range for the second filter is 150 Hz to 15 kHz. There is ample range overlap to
allow for two closely spaced notches, if needed.
13. OCTAVE: Adjusts the bandwidth (Q) of the parametric filter. It is variable from two 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.
14. 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.
15. 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 dynamics’ 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