Allen & Heath AP5195 用户手册

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页码 36
18 
PA User Guide 
The STEREO Channel 
Dual Stereo Inputs
   Each stereo channel has two 
independent stereo inputs, ST1(3) and ST2(4).  For 
convenience, one uses RCA phono connectors, the other uses 
TRS jacks.  The two inputs mix together to feed the channel 
strip, or ST1(3) can be routed direct to the LR mix instead, 
leaving ST2(4) to feed the channel.  This provides a very 
flexible arrangement for mixing up to four stereo sources. 
ST1(3) INPUT
   RCA phono inputs for connecting line 
level stereo signals.  These connectors are popular with 
consumer  and semi-professional equipment such as tape 
deck, video camera, computer, CD and MiniDisc players. 
ST2(4) INPUT
   TRS jack inputs for connecting line level 
stereo signals.  The inputs are unbalanced but can also accept  
balanced sources.  The ring connection grounds the –ve (cold) 
signal to unbalance a connected balanced source.  Typical 
applications include stereo keyboards, voice modules, effects 
processors and sub mixers. 
  Using the  stereo channels   These inputs are intended 
for local stereo sources.  The unbalanced connections work 
fine with the higher voltage levels and low impedance 
associated with such equipment.  If you need to connect 
equipment further than 10 metres away we recommend you 
use the mono channel balanced line inputs or DI boxes feeding 
the long cables to the mic inputs. 
ST1(3) Mode Switch
   This small switch is recessed to 
prevent accidental operation once it is set.  In its up position it 
is flush with the panel and mixes the ST1(3) signal with ST2(4) 
to feed the stereo channel.  Use a pen or similar pointed object 
to press the switch if you want to route the ST1(3) signal direct 
to the LR mix instead of the stereo channel.  
    Mixing two stereo signals into the channel      (Switch 
flush with panel).  There are many situations where it is 
convenient to combine two sources into one channel.  For 
example, you may have two MiniDisc players being used for 
backing tracks or sound effects, a stereo keyboard together 
with additional MIDI controlled voice module, two effects 
processors returning into one effects channel, or simply two 
unrelated sources being used at different times.  Use the two 
GAIN controls to adjust the balance between the sources. 
    Sending ST1(3) direct to LR   (Switch pressed, below 
panel).  Some sources may only require ‘set and forget’ routing 
to the main LR mix.  For example, an external reverb processor 
return with its levels mixed using the channel aux sends, or the 
outputs of a stereo sub mixer with local control of its mix.  
Routing ST1(3) in this way frees up the stereo channels for 
other sources.  Adjust the level using the ST1(3) GAIN control 
from fully off to +10dB boost. 
 
GAIN
   Adjusts the sensitivity of the channel preamp to 
match the connected source to the 0dBu operating level of the 
console.  The control has a range from fully off to +10dB boost 
so that sources from -10dBu and higher can be connected.    
  Setting the gain   Use the channel PFL function to view 
the signal level on the console meters.  Adjust the gain control 
for average signal level around meter ‘0’ with loudest peaks no 
more that ‘+6’.  If you see the channel PEAK indicator flash 
back the gain off a little. 
  
5
0
LR
10
11-12
-20
-30
OO
-10
10
0
5
O
-20
-30
O
-10
R
ST2/4
L
GAIN
L
ST1/3
R
LR
GAIN
CHAN
STEREO CHANNEL
+
SUM
TO LR