
4
ULTRACOUSTIC ACX450/ACX900/ACX1800
1. INTRODUCTION
Thank you for choosing the ULTRACOUSTIC amplifier. You have
purchased a modern 2-channel amplifier that guarantees
excellent sound quality for various applications yet is easy to
operate. The ULTRACOUSTIC comes with a wide range of
features such as two integrated, 24-bit multi-effect processors
or the FBQ Feedback Detection system which help you to
fine-tune your sound. Due to the many possibilities of connecting
external effects units and playback feeds, the ULTRACOUSTIC
is a real all-rounder leaving nothing to be desired.
+Please read this manual t familiarize y urself with
the c ntr l elements f the unit and its functi ns.
After y u have carefully read this manual, keep it
f r future reference.
1.1 Before you get started
1.1.1 Sh pment
The ULTRACOUSTIC was carefully packed at the assembly plant
to ensure secure transport. If the cardboard box is damaged,
please inspect the ULTRACOUSTIC equipment immediately for
physical damage.
+Damaged equipment sh uld NEVER be sent directly
t us. Please inf rm the dealer fr m wh m y u
acquired it immediately as well as the trans-
p rtati n c mpany fr m which y u t k delivery.
Otherwise, all claims f r replacement/repair may
be rendered invalid.
+If the unit needs t be shipped, please always use
the riginal packaging t av id damage.
+Never let unsupervised children play with the
ULTRACOUSTIC r with its packaging.
+Please disp se f all packaging materials in an
envir nmentally-friendly fashi n.
1.1.2 In t al operat on
Please make sure that your ULTRACOUSTIC is provided with
sufficient ventilation, and never place it on other amplifiers or in
the vicinity of a heater to avoid the risk of overheating.
+Bef re plugging y ur ULTRACOUSTIC int a p wer
s cket, please make sure y u have selected the
c rrect v ltage:
The fuse retainer near the power cord connector has three
triangular markings. Two of these triangles point in opposite
directions. Your ULTRACOUSTIC is set up for the voltage
indicated near these markings, and can be altered by turning the
fuse mount by 180 degrees. ATTENTION: This d es n t apply
t exp rt m dels built f r 120 V, f r example!
+If y u use y ur ULTRACOUSTIC unit with a different
v ltage, y u must change the fuses acc rdingly.
The c rrect value f the fuses needed can be f und
in the secti n SPECIFICATIONS.
+Faulty fuses must be replaced with fuses f
appr priate rating, with ut excepti n! The c rrect
value f the fuses needed can be f und in the
secti n SPECIFICATIONS.
Power is delivered via the cable that was delivered with the
ULTRACOUSTIC. All mandatory safety precautions have been
adhered to.
+Please make sure that all f y ur equipment is
gr unded at all times. F r y ur wn pr tecti n, y u
sh uld never tamper with the gr unding f the cable
r the unit itself. The unit shall always be c nnected
t a mains s cket utlet with a pr tective earthing
c nnecti n.
1.1.3 Onl ne reg strat on
Please, do remember to register your new BEHRINGER equipment
right after your purchase by visiting www.behringer.com and
kindly read the terms and conditions of our warranty carefully.
Should your BEHRINGER product malfunction, our goal is to have
it repaired as quickly as possible. To arrange for warranty service,
please contact the retailer from whom the equipment was
purchased. Should your BEHRINGER dealer not be located in
your vicinity, you may directly contact one of our subsidiaries.
Corresponding contact information is included in the original
equipment packaging (Global Contact Information/European
Contact Information). Should your country not be listed, please
contact the distributor nearest you. A list of distributors can be
found in the support area of our website (www.behringer.com).
Registering your purchase and equipment with us helps us
process your repair claims quicker and more efficiently.
Thank you for your cooperation!
2. CONTROL ELEMENTS
AND CONNECTIONS
2.1 Front panel
The ¼" jack connector labeled INSTR(UMENT) is the input
of the instrument channel of your ULTRACOUSTIC to
connect your acoustic guitar. Use a commercially available
mono jack cable. We recommend using a cable with impact
sound insulation so as to avoid unpleasant incidences
during a rehearsal or concert.
The PHASE switch (not included in ACX450) reverses
the instrument channel phase by 180°. Use this function
to eliminate feedback problems or phase errors of dual
pickup systems.
The GAIN controller is used to determine the volume of
the respective channel.
With the TUNER switch (not included in ACX450),
you can mute the channel. There is a permanent signal at
the TUNER connector at the rear of the unit. You
have the option to connect an external tuner to this jack
(e.g. BTR2000, TU100).
When the input signal overdrives the instrument channel,
the CLIP LED located in the TUNER switch is on (only in
ACX1800). Reduce the input gain with the GAIN controller
until the CLIP LED is off. Occasional flashing of the CLIP
LED caused by signal peaks is harmless though, as the
instrument channel has sufficient headroom.
This is the FBQ EQUALIZER. Each sliding controller
controls a specific frequency range. In position 0,
the frequency is not adjusted. To boost a frequency range,
move the respective sliding controller up. To lower its
volume, move the sliding controller down. The maximum
boosting or damping range is 12 dB.
Press the FBQ switch to activate the FBQ function. While
the FBQ is switched off, the controller LEDs are lit with
the same brightness. When the FBQ is on and you play
your instrument, the LEDs brightness varies, depending
on the energy content of the associated frequency range.
This visual feature supports you in adjusting the sound
and eliminating feedback. The equalizer is always
activated, irrespective of whether the FBQ function is on.
2. CONTROL ELEMENTS AND CONNECTIONS