Acoustic Image Flex - Manual (Page 8)

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you will hear the effect in a boomy bass situation. Experiment with the
position of the control to give you the sound you like best.
The phase reverse switch is used to reduce feedback and to control
phase interactions between the two channels. If you are using two
pickups or a mic and a pickup, you will find the phase reverse switch to
come in handy. Phase related interactions between a mic and a
pickup or two pickups can be cleared up by reversing the phase of one
of the channels. Mic feedback can be reduced by reversing the phase
of the signal. You should experiment with the phase reverse switch to
see if the effect is one that you like.
If desired, the phase switch can be converted to a speaker emulation
filter by moving a jumper on the rear of the Flex Pre circuit board. How
this is done is described in the section entitled “Jumper Options.” This
can be done on either or both channels.
The speaker emulation filter is a low pass filter that modifies the
preamp output to sound like a single speaker guitar amp. It rolls the
frequency off starting a 4 kHz. If you are a guitar player, you may find
this to be a desirable sound, it will allow you to get a more “classic” jazz
guitar sound.
The Flex Pre has an output (“Send”) and input (“Return”) capability in
each channel to allow you to use effects boxes. The effects loop for
each channel is located on the rear panel of the unit. See page 10 for a
diagram of the rear panel. The send output is affected by the input
volume and tone controls and can also be used as a preamp output for
driving other power amplifiers. Because the effects loop is a parallel
type, plugging something into the send output does not interrupt the
signal path. So, a tuner can be plugged into the send output without
affecting the signal going through the amp.
The return input can also be used as an auxiliary input for connecting
other line level signals such as a CD player.
An XLR jack is provided for a Direct Out connection that allows the
preamp output to be fed to mixing boards of house PA systems or
recording studios. As a result, the instrument(s) connected to the unit
can be recorded or further amplified by the house PA system. The
direct out jack is located on the front panel of the Flex Pre. 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).
Effects Loop
Direct Out
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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 connected speaker system) and the “house”
volume (the volume in the house PA system) when the unit is used with
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.
If the direct out signal is overdriving the mixing board, switch in the 10
dB pad to reduce the signal output level.
A switch is provided to allow you to mute the output of the Flex Pre
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 is on the
front panel and when it is on, the switch is illuminated.
The Flex Pre is connected to the Flex Cab via the RJ-45 jack. There
are 1/4 inch jacks labeled “Preamp Out” on the rear panel for
connecting the unit to other powered cabinets. When the Flex Pre is in
mono mode, the top jack, labeled “Ch 1” or “Mono” is the output to use.
An internal jumper option is available to allow the Flex Pre to operate
in true stereo mode. The output of channel 2 can by disconnected
from the jack labeled “mono” on the rear panel and connected to the
channel 2 output jack by changing the position of a jumper on the
backside of the preamp control board (see the “Jumper Options”
section for details). When in true stereo mode, the output of each
channel is independently available from each preamp output jack.
Note that when in the stereo mode, channel 2 is no longer connected
to the Rj45 output, so it will not be heard through a Flex Cab connected
to the Flex Pre.
The Flex Pre has a high-quality, 24 bit digital effects processor. Three
variable effects are available: a reverb with variable decay time, a
reverb/delay with variable delay, and a delay with variable delay time.
A four position switch selects the program (Off, Reverb, Delay/Reverb
Mute Switch
If you are not
getting any sound out of the amp, check to make sure that the
mute switch is off.
Preamp Output
Stereo Operation
Effects