Stereo Input Channel - ALLEN & HEATH GL4800 User Manual

The STEREO Input Channel
The stereo channel has two independent input sections: XLR IN for mono
microphone or line input, and STEREO LINE IN on jacks for sources such as
+48V
stereo keyboards, voice modules and effects returns.
channel as a mono XLR mic/line input the stereo line input can be
POLARITY POLARITY
independently routed to L-R for a stereo effects return or additional line input.
The XLR inputs on adjacent channels can be patched into a stereo line when
MIC
using stereo or paired microphones.
LINE
0dB
PAD
20 XLR MIC/LINE INPUT - This section is the same as the mono channel input
10
30
XLR
-10 40
except that it has only the XLR input for both mic or line. It uses the same
GAIN
10
50 wide ranging balanced pre-amp stage and includes the swept lo-cut filter and
LINE
MIC
6
-14
40dB
60
insert. Refer to the MONO INPUT section for a detailed description of these
50Hz
HPF
controls.
30 100
20 200
STEREO LINE INPUT - The left/mono and right inputs feed a balanced pre-
amp stage with GAIN variable from fully off to +10dB boost.
OFF 400Hz
POLARITY (R) to reverse the phase of the right input signal to correct phase
POLARITY
(R)
differences between the inputs. The WIDTH control is normally set to the
STEREO
centre detented position for normal stereo. Turn anticlockwise to narrow the
WIDTH
stereo image until it becomes mono. Continue anticlockwise to open up the
MONO
stereo image but with left and right reversed. Turning clockwise from centre
REVERSE WIDE
accentuates the stereo effect by producing a phase enhanced "wide" image.
0dB
-5
STEREO
Press PFL to listen to the stereo signal on headphones or local monitor
-10
GAIN
+5
without affecting the main outputs.
-20
-30
+10dB
DIRECT TO L-R routes the stereo line signal to L-R independent of the main
DIRECT
stereo channel which you may be using as a mic/line XLR input. The GAIN
TO
L-R
control adjusts the level to L-R. PFL lets you check the post-gain, post-width
stereo signal independent of the main channel PFL.
STEREO
PFL
XLR/STEREO selects the input source to the main stereo channel. When
XLR
STEREO
pressed the stereo line input is selected, when released the XLR mic/line
input is selected.
HF
12kHz
EQUALISER - This provides separate, simultaneous stereo control of 4
frequency bands. Each band may be boosted or cut by up to +/- 15dB. HF
-15 +15
and LF have a shelving response and affect the high (treble) and low (bass)
HM
2.5kHz
frequencies respectively.
response and affect the upper and lower mid frequencies respectively. MF1
-15 +15
is centred on 2.5kHz (presence) and MF2 is centred on 250Hz (warmth).
LM
Careful use of the equaliser can go a long way to brightening up the sound of
250Hz
your stereo instruments, or tuning out the noise characteristic of many lower
cost effects units.
-15 +15
LF
AUXILIARY SENDS - 10 aux sends are provided. These work in the same
70Hz
way as the mono channel. Note that the left and right signals are combined
as mono aux sends. No direct output facility is available.
-15 +15
EQ IN
ROUTING, PAN, METER and PFL - These are the same as on the mono
channel. When a stereo input is selected PAN acts as a balance control to
adjust the level of the left and right signals relative to each other. The meter
indicates the pre-fade left and right signals combined. PFL operates in stereo
so that you can hear the image of the stereo source and check the relative
levels on the L and R meters.
22
MF1 and MF2 have a peak/dip (bell shaped)
When using the
Press
GL4800
User Guide