Behringer Ultracoustic ACX900 Owner's Manual

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 to familiarize yourself with

the control elements of the unit and its functions.

After you have carefully read this manual, keep it

for future reference.

1.1 Before you get started

1.1.1 Shipment

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 should NEVER be sent directly

to us. Please inform the dealer from whom you

acquired it immediately as well as the trans-

portation company from which you took delivery.

Otherwise, all claims for replacement/repair may

be rendered invalid.

If the unit needs to be shipped, please always use

the original packaging to avoid damage.

Never let unsupervised children play with the

ULTRACOUSTIC or with its packaging.

Please dispose of all packaging materials in an

environmentally-friendly fashion.

1.1.2 Initial operation

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.

Before plugging your ULTRACOUSTIC into a power

socket, please make sure you have selected the

correct voltage:

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 does not apply

to export models built for 120 V, for example!

If you use your ULTRACOUSTIC unit with a different

voltage, you must change the fuses accordingly.

The correct value of the fuses needed can be found

in the section SPECIFICATIONS.

Faulty fuses must be replaced with fuses of

appropriate rating, without exception! The correct

value of the fuses needed can be found in the

section 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 of your equipment is

grounded at all times. For your own protection, you

should never tamper with the grounding of the cable

or the unit itself. The unit shall always be connected

to a mains socket outlet with a protective earthing

connection.

1.1.3 Online registration

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