Input Channels; Mic/Line Level Selection; Gain; Faders - Sound Devices 442 Nordic User Manual And Technical Information

Input Channels

The inputs of the 442 consist of four, full-featured microphone preamplifi ers. Each channel has a wide gain
range to accommodate nearly all signal types. The 442 accepts signals ranging from low-sensitivity ribbon and
dynamic microphones to medium level wireless and condenser mic outputs up to "hot" line levels.
442 input channels are transformer-balanced. The isolation characteristics of transformers are superior to other
balancing techniques for the hostile and uncontrolled environments of fi eld production. Transformers provide
galvanic isolation from the driving source, meaning there is no direct electrical connection. Signals are "trans-
formed" magnetically. The input transformers in the 442 use premium magnetic core material to achieve high
signal handling capability (especially at low frequencies) while keeping distortion to a minimum. Because of
their inherently high common mode impedance, transformers are unrivaled by any other type of input for
common-mode noise rejection.
The inputs of the 442 can be used as either balanced or unbalanced connections. When unbalancing, ground
pin-3 to pin-1. There is no change in gain between unbalanced and balanced connections into the 442.

Mic/Line Level Selection

The Mic/Line switch is used to select the input level for the channel. Taking into account all available gain
stages, the 442 has up to 84 dB of available gain from mic input to line output. When in the LINE position, the
input channel sensitivity is reduced by 40 dB.

Gain

Like traditional mixing consoles, the 442's microphone preamp gains are set via the Gain control. The Gain,
or trim, adjusts the input sensitivity of the channel input so that the channel fader can be set to operate in a
usable range. Once set, the Gain is typically kept at the set level and all mixing is done on the Channel Fader.
The Gain adjustment features a pop-up knob so that it can be adjusted easily and then hidden from the mixing
surface.

Faders

While both the Gain and the Fader control the gain of a given channel, the Fader is the primary channel level
control. The Gain can be thought of as a "coarse" gain adjustment to be adjusted during setup, and the Fader is
a "fi ne" gain adjustment to be adjusted while recording. With a properly set up Gain, the Fader can be set to a
nominal 0 (unity) level. With the Fader at unity, the dynamic range of the mixer is maximized. There is a wide
range of gain control for the input, allowing for smooth gain changes with adequate control of attenuation and
gain.

Microphone Powering

Condenser microphones require power for various parts of their operation. The 442 can provide phantom or T-
power to each input and is selected per input. The 442 can provide up to 10 mA to each input at 48 V, suffi cient
for the most power-hungry condenser microphones. When acceptable, use 12 V phantom to extend battery
runtime. The 12 V/48 V phantom voltage switch is located on the input panel.
Phantom Power
Phantom powering is a method of providing power to microphones by applying a voltage to the microphone
using the same wires that carry the audio signal. Phantom power is produced by the 442 for microphones that
require power. Phantom powering utilizes a fi xed DC voltage between 12 and 48 volts. This voltage is resis-
tively applied to pin-2 and pin-3 of an XLR connector relative to pin-1 (there is no voltage difference between
the signal pins -2 and -3—a dynamic mic can operate just fi ne in the presence of phantom powering.)
Many phantom-powered mics will operate at 12 V with no difference in performance as compared to operating
off of 48 V. As the mics draw the same current no matter what the phantom voltage, operating at 48 V con-
sumes four times the power as 12 V with no performance gain! This excess power draw can make a signifi cant
difference in battery life and is the reason that the 442 allows the user to select phantom voltage.
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