Acoustic Image Flex - Manual (Page 9)

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and Delay). There are illuminated switches to select which of the two
channels is processed by the effects unit. Either channel can be
connected to the effects unit. If both switches are engaged,
theselected program appears in both channels. A level control affects
the amount of effect that is heard in the signal (the “wet/dry” mix) and
another control affects the rate of the effect (reverb decay time or
delay time). For example, the rate control has enough range that the
Reverb program can be varied from a large hall to a small room. You
should experiment with both the program selection and the level and
rate controls to find the sound that you prefer. When effects are not
used (program switch in the off postion), the switches for both
channels should be off and the level control should be turned fully
counterclockwise.
The effects processor in the Clarus preamp is a stereo unit. As a result,
a single input can be converted to a stereo output as far as the effects
are concerned. The 1/4 inch jacks labeled “Stereo Out” on the rear
panel are where the pseudo stereo signals are accessed. To operate
in pseudo stereo mode, plug an instrument into channel 2 (
) and connect a separate powered speaker (such as the
Flex Cab) or power amp and speaker combination to each of the
“Stereo Out” jacks located on rear panel. The effects level control
affects the wet/dry mix and the input level control affects the overall
level of the signal. The master level control has no effect. You should
experiment with the operation of the pseudo stereo mode to find the
sound you like best.
There is headphone output on the rear panel of the Flex Pre. You can
plug a standard 1/8 inch stereo plug into this output to connect a
headphone for private listening. If your headphone has a 1/4 inch
plug, you can buy an adapter to allow you to use the 1/8 inch output
jack.
When you plug into the jack, the preamp output is muted. Sound will
only be heard through the headphones. The headphone is connected
to the output of the preamp so all of the controls on the preamp,
including effects, will be heard through the headphone. When the
headphone plug is removed from the jack, the amp will come back on.
Anytime anything is plugged into the headphone output jack, the amp
will be muted so make sure that nothing is plugged into the jack when
you want to use the amp normally.
Pseudo Stereo Operation
only
channel 2 has this feature, connecting to channel 1 won’t work in
this mode
Headphone Output
The headphone output is to be used only for connecting a
headphone unit, do not use it as line out or to drive a low
impedance speaker.
Under extreme playing conditions such as high volume or when
driving a low impedance speaker load, the amplifier and speaker
system connected to the Flex Pre may be pushed beyond their limits.
When that happens, you will hear high distortion and, if connected to
the Flex Cab, you may even cause the overcurrent protection circuit to
operate resulting in an interruption of sound. The limiter switch,
located on the rear panel of the Flex Pre, is provided to allow the amp
to operate under these conditions with lower distortion or without
having the overcurrent circuit kick in. The limiter reduces the peak
signal that is driving the power amp, thereby reducing its peak output
with the result of lower distortion. If you find yourself having to play in
extreme conditions that cause the amp to have too much distortion or
even signal interruption, engage the limiter and see if that helps the
situation.
If the Flex Pre is to be used in an application without the Flex Cab, the
supplied power supply can be used. Simply plug the supply into the AC
outlet and then plug the output of the supply into the power jack on the
rear panel. The external power supply operates from 100V to 240V
AC, so the Flex Pre can be used in standalone mode anywhere in the
world. The appropriate adapters for the ac plug are included.
On the back side of the Flex Pre circuit board are several user-
selectable options: one selects the gain level in the input stage,
another selects between a phase reversal and a speaker emulation
filter and the last disconnects channel 2 from the output buss and
connects it to an output jack. To access the back side of the circuit
board, remove the 6 allen-head screws on the preamp front panel and
lift the preamp module out of the chassis.
A photo of the back side of the circuit board is shown below:
Limiter Switch
External Power Option
Use only the external power supply provided by Acoustic Image,
otherwise, the Flex Pre may not operate properly.
Internal Jumper Options
15
Gain Jumpers
Filter Jumpers Ch 2 Jumper