SPL Frontliner Modular Recording Channel - Manual (Page 16)

16
Frontliner
Preamplifier
Control Elements
Phase reverse
The phase reverse function reverses the polarity of the microphone signal, inverting the
phase (by 180°) to correct phase-inverted signals caused by multiple signal sources. A voice-
over artist, for example, hears himself during recording through the headphones and simul-
taneously through the bones in his head. Phase inversion will cause an unnatural sound, and
even minimal variations in distance to the microphone will cause drastic variations in the
sound. Phase inversion is also commonly encountered when using multiple microphones on
a single sound source. We recommend checking for correct polarity before each recording.
Phase reverse can be applied to the preamplifier microphone and line inputs.
High-pass filter
This switch activates the high-pass filter, which operates from 85 Hz downwards with 6 dB/
octave (often also called a “rumble filter“). The filter prevents the amplification of unwanted
low-frequencies. Compared to 12 dB/octave filters, the 6 dB filter works relatively moderate,
but very musical.
The high-pass filter can be applied to all three preamplifier inputs (microphone, line, and
instrument).
PAD
The PAD switch attenuates the microphone input by 20dB. High-level input signals can be
attenuated in order to prevent over-driving the preamplifier. The Frontliner has a minimum
pre-amplification of +13 dB. But with signals from drums or brass this may already be too
much. Engaging PAD attenuates the minimum pre-amplification (MIC GAIN control fully
counter clockwise) to -7 dB, thus providing a useful gain control range for loud input signals.
INSTRUMENT input
The INSTRUMENT input jack is placed on the front for easy access. It should be used to connect
instruments like e-bass and guitars, acoustic guitars with pick-ups, etc. The Instrument input
features a 1 MOhm (one mega Ohm) input impedance. Line signals with lower impedances,
such as from D/A converters, samplers, synths, etc. should be connected to the rear LINE IN
socket.
IMPORTANT: As long as an instrument is plugged into front INSTRUMENT input, the rear
panel LINE IN input is deactivated.
48 V PAD Ø
48 V PAD Ø
48 V PAD Ø
IN
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