Acoustic Image Series4 - Manual (Page 5)

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Direct Out
Mute Switch
If you are not
getting any sound out of the amp, check to make sure that the
mute switch is off.
Stereo Operation
Note that channel
2 will not be heard through the speaker system unless the Ch 2
switch is in the depressed or on position. If you are not hearing
channel 2 in the output, check to be sure that the switch is on.
An XLR jack is provided for a Direct Out connection that allows the
system’s output to be fed to mixing boards of house PA systems or
recording studios. As a result, the instrument amplified by the unit can
be recorded or further amplified by the house PA system. In the two
channel amps and combos, the Direct Out signal is the combined
output of the two channels. A switch is provided to allow you to select
whether the output from the Direct Out jack is affected by the tone
controls (post EQ) or not (pre EQ).
With the switch in either the pre or post EQ position, the input level
control affects the level of the Direct Out signal, the master level does
not. This allows independent adjustment of the “stage” volume (the
volume coming from the combo amp) and the “house” volume (the
volume in the house PA system) when the unit is used as a stage
monitor. Once the level has been set for the house, if more volume is
needed on stage, the master level can be increased. This will increase
the stage volume but not the volume in the house PA.
A ground lift switch is available to “lift” the ground from the output of the
direct out--reducing noise should a ground loop create hum when the
unit is connected to a mixing board.
A switch is provided to allow you to mute the output of the amplifier
without having to turn the amp off. This will allow you to tune your
instrument on stage without being heard. The amp output and direct
out signals are both muted by the switch. The mute switch has a red
button on it to remind you that it is an important switch.
The two-channel preamp can be operated in stereo mode. When it is
in the “on” position, the switch labeled “Ch 2” connects the channel to
the internal power amp and speaker. When it is in the “off” position, it is
disconnected from the internal amp but is accessible from the channel
2 send output. By connecting the send output to a satellite power
amplifier, and putting the switch in the off position, the preamp
operates in stereo mode. Note that channel 2 remains in the direct out
signal even when the switch is in the off position. This is done since
stereo operation is typically a “stage” mode but not a “house” mode
(house systems are typically not stereo). The Ch 2 switch has a red
button to remind you that is is an important switch.
Signal Flow Diagram
Two channel version shown, the one channel
version has channel 2 removed from the diagram
One Channel Control Panel
Input
Level Bass Mid Treble Level
Channel 1
Freq
Direct Out
Master
Power
Level Effects
Phantom
Hall
Room
Plate
Delay Ambient Chorus
Flange
Off On
Off On Low Cut
Send
Return
Post EQ Mute
Ground
lift
Off On
Effects Loop
30 400
60
Phase Inv Off On Mic
Atten
PRE EQ OUT
BUFFER
INPUT BUFFERS
INPUT BUFFERS
OFF ON
-10 dB MIC
ATTEN
ON OFF
-10 dB MIC
ATTEN
FILTER
OFF
CUT
FILTER
OFF
CUT
180
PHASE INV
OFF
180
PHASE INV
OFF
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