Allen&Heath GL2800 - Manual (Page 18)

18 GL2800 User Guide
The STEREO Input Channel
Each GL2800 stereo channel features a mono microphone preamp
as well as a stereo line input. These sources can be mixed together
into the channel or split using the mic breakpoint, so providing a
unique flexibility. For example, you could patch the mic stage as an
independent preamp for an ambience microphone feeding a
recording, or for a system calibration microphone, while the stereo line
input returns an external effects processor to the mix. Two stereo
channels could be linked so that the mic preamps cross patch to
provide one stereo mic and one stereo line channel.
MIC INPUT Similar to the mono channel microphone preamplifier.
A rear panel MIC OUT breakpoint socket is provided so that the mic
stage can be used independently. Plugging a jack into the MIC OUT
socket breaks its signal path to the stereo channel.
WARNING: Do not connect unbalanced sources or cables to
inputs with phantom power selected. To avoid loud clicks always
mute the channel before switching +48V on or off and when
plugging or unplugging microphones.
STEREO LINE INPUT A level control adjusts from fully off to
+16dB gain. The L input signal is normalled through the R input
socket so that a mono source may be plugged in to feed both left and
right sides of the stereo channel.
EQ Similar to the mono channel, but the two peak/dip mid bands
are fixed at 250Hz and 2.5kHz centre frequencies.
AUX SENDS These work as described for the mono channel, but
the L and R sides of the stereo signal sum together to feed Auxes 1 to
8 in mono. Aux 9-10 is fed with the stereo signal. The auxes can be
switched pre or post-fader but are always sourced post-EQ.
BAL Balances the level of the L signal against the R signal to
compensate for differences in the source, or to position the signal
within the stereo image.
MUTE When pressed, all the channel pre and post-fade signals are
turned off except the MIC OUT and any stereo routed direct to LR.
PFL Press PFL to display the summed L+R pre-fade channel signal
on the monitor meters and listen to it in the headphones and local
monitor without affecting the main outputs.
METER As the mono channel, but the left and right signals are
summed to display in mono.
ROUTING As the mono channel, but routes the left signal to L and
odd groups, right signal to R and even groups, and sums L and R to
feed the M mix in mono.
FADER The stereo fader provides +10dB maximum boost above
its normal unity gain 0dB position
MUTE GROUPS Assign the stereo channel to any combination of
the 4 mute groups by pressing these switches.
SIG
0
+6
PK!
PFL
M4
M3
M2
M1
7-8
5-6
3-4
1-2
L-R
M
10
5
0
5
10
20
30
00
+6 OO
250Hz
2k5
12k
HF
HM
LM
80Hz
LF
+15 -15
+15 -15
+15 -15
+15 -15
EQ IN
STEREO
GAIN -5
16
5
O
0
-30
-20
O
-10
100Hz
POLARITY
LINE
+48V
HPF
(PAD)
STEREO
=
R L
BAL
POST
PRE
POST
PRE
9-10
AUX
+6 O O
+6 OO
1
2
AUX
AUX
+6 OO
+6 OO
AUX
3
4
AUX
POST
PRE
+6 OO
OO +6
5
AUX
AUX
6
8
AUX
AUX
7
+6 O O
O O +6
=
R
EVEN
L
BAL
ODD
MUTE
60 40 -14 6
30 40
50
0
20
GAIN