Acoustic Energy Acoustic Image Stereo Amplifier User Manual

Combo

Amplifiers

IMPORTANT SAFETY INSTRUCTIONS

Contents

1) Read these instructions.

2) Keep these instructions.

3) Heed all warnings.

4) Follow all instructions.

5) Do not use this apparatus near water.

6) Clean only with a dry cloth.

7) Do not block any ventilation openings. Install in accordance
with manufacturer’s instructions.

8) Do not install near any heat sources such as radiators, heat
registers, stoves or other apparatus (including amplifiers) that
produce heat.

9) Do not defeat the safety purpose of the polarized or
grounding-type plug. A polarized plug has two blades with one
wider than the other.A grounding type plug has two blades and
a third grounding prong. The wide blade or the third prong are
provided for your safety. If the provided plug does not fit into
your outlet, consult an electrician for replacement of the
obsolete outlet.

10) Protect the power cord from being walked on pinched
particularly at plugs, convenience receptacles, and the point
where they exit from the apparatus.

11) Use only attachments/accessories specified by the
manufacturer.

12) Use only with the cart, stand, tripod, bracket, or table
specified by the manufacturer,or sold with the apparatus.

13) Unplug this apparatus during lightning storms or when
unused for long periods of time.

14) Refer all servicing to qualified service personnel. Servicing
is required when the apparatus has been damaged in any way,
such as power-supply cordor plug is damaged, liquid has been
spilled or objects have fallen into the apparatus, the apparatus
has been exposed to rain or moisture, does not operate
normally or has been dropped.

Welcome

The Basics 1

Operation 2

Power 2
Preamp 2
Inputs 2
Controls 3
Notch/Low Cut Filter
Control Panel Drawings 4
Signal Flow Diagram 4
Effects Loop 6
Direct Out 6
Mute Switch 6
Stereo Operation 7
Effects
External Speaker Jack 7

Speaker Placement 8

Tilt Mechanism 8
Tweeter Switch 8
Description of the Corus Combo 8
Care 8
Warranty And Repair 9
Specifications 10

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7

The information in this manual is subject to change without notice.
No part of this manual may be reproduced by mechanical,
electronic or other means in any form without prior written
permission from AcousticImage.

The Acoustic Image logo is a registered trademark of Acoustic
Image LLC. Contra, Coda R, Corus and ContraEX are trademarks
of Acoustic ImageLLC.

Wel

come toAcousticImage

!

You have purchased a state-of-the-art musical instrument amplifier system,
combining purity, power and portability in a package that sets a new standard
in high fidelity amplification.

Each of our designs is engineered to accurately reproduce the sound of
acoustic and electric instruments, delivering flat frequency response across
the entire musical spectrum; extended, tight, well-controlled bass; and
complete clarity of sound reproduction.

This manual provides operating information for your Acoustic Image Contra,
Coda R and Corus combo amp or Contra EXextension speaker cabinet.

The Basics

Our combo amps all use the same superb class-D 400-watt (4 ohms) power
amplifier, the same compact three-way speaker system (also used in the
Contra EX, but the speaker configuration of the Corus is slightly different) and
the same sophisticated, sensitive preamplifier. The features of the preamp and
the speaker configuration define the specific combomodel.

The power amp is a high efficiency design that requires no external heat sinks
or coolingfans and is capable of driving loads as low as 2 ohms. AC power and
output speaker jacks are located on the rear of the enclosure. A standard,
three-prong detachable AC power cord is used to provide power to the unit,
while AC voltage selection switch allows the unit to operate at 115V/60 Hz or
230V/50 Hz. Japan models operate at 100V, 50/60 Hz only. See the rear panel
of your amp to verify the AC voltagecapability.

The Contra combo is equipped with a one-channel preamp, the Coda R adds a
second, identical channel and a six-program effects unit. The Corus combo
has the same preamp as the Coda R but uses a different speaker system that
gives it a somewhat different sound fromthe other combos. The input channels
of both preamp types incorporate combo jack interfaces that allow eithera high
impedance instrument input (to optimize the sound of piezo-type pickups) or a
mic input, an effects loop with return level control, a
selectable notch/low cut filter for feedback control and reduction of low
frequency boominess, a direct out capability with ground lift and pre/post EQ
switch, a master level control and a mute switch. The two-channel preamp of
the Coda R and Corus has a switch that allows the second channel to be
disconnected from the main amp and connected to a satellite power amp to
create a stereo system.

All of our speaker enclosures incorporate a 10-inch downfiring woofer,a 5-inch
frontfiring midrange, and a 1-inch defeatable tweeter. The Corus uses a
different woofer that gives it a sound that is better for instruments like guitar. A
built-in, spring loaded tilt mechanism allows the cabinet to be tilted back to
better direct sound to your listening position. The cabinet is made of an
acoustically inert, high durability, injection molded polymer material which
dramatically reduces the weight of the cabinet. Each unit comes with a fitted
slip cover and shoulder strap. Both padded and hard shell cases are available
as accessories.

While our combos and speakers are designed to play loudly--and clearly-­enough sothat you can be heard in most gigging situations, they are not suited
to playing at extreme volumes. Generating high SPLs may require an
extension cabinet like the Contra EX or augmentation by a larger house
system.

a three-band EQ,

1

Operation

Power

On

Tweeter Switch

Operation of a 100

CAUTION: TO REDUCE
THERISK OF FIRE, REPLACE
FUSEWITH THE SAME TYPE

6.3A FAST BLOW FUSE

CAUTION: TO REDUCE THE
RISK OF ELECTRIC SHOCK,
DO NOT REMOVE COVER.
NOUSER SERVICEABLE PARTS
INSIDE. REFER SERVICING
TO QUALIFIED PERSONNEL.

Fuse

I

Power Switch

0

AC Input

115/230 VAC

50/60 Hz

400 Watts

115V

Voltage Switch

115/230V

Speaker Output 4 minW

Combo Rear Panel

Plug the detachable AC power cord into the receptacle on the back of the amp
and into a wall receptacle. A power switch next to the AC connector turns on
power to the pre- and power amps, illuminating a “power on” indicator on the
front panel of the amp. A 6.3-amp fast blow fuseis mounted on the backpanel.
To replace the fuse, turn off the amp, remove the AC cord and use a small
screwdriver to remove the fuse from the fuse holder. A spare fuse is included
with this manual.

All combos will work with either 115 volt,60 HzAC or 230 volt, 50 Hz AC power.
A switch located on the rear panel selects the appropriate voltage. Note that
the correctAC power cord must be used for connection to the appropriate wall
plug. If you do not have the right cord, you can buy one from an electronics or
computer store. Be sure the switch is in the correct position for the intended
application.

Operation at 230 volts with the switch in the 115 volt position

will damage the unit.

Please note that units sold in Japan operate at 100 volts only. The above
mentioned voltage switch is not available for these units.

volt amp at any other voltage than100 volts will damage the unit.

Preamp

Refer to the signal flow diagram and the control panel drawings for more
information (page 4).

Inputs

The Contra, Coda R and Corus use combo jacks for the input to each channel
of their preamp. Either an XLR or 1/4 inch connector can be plugged into this
type of jack. The 1/4 inch input has a 1 megohm input impedance that is
optimized to get the best sound from piezo pickups. The XLR input is a low
impedance balanced input with sufficient gain to allow microphones to be
plugged into it. Phantom power is available through the connectorfor powering
a mic or outboard preamp and can be activated using the push button switch
located next to the connector. To avoid an audible “pop”, set the mic input level
control all the way off when switching on the phantom power. An LED indicates
when phantom power is on. The two channels of the Coda R and Corus
combos can blended to mix two instruments, 2 microphones or a mic and an
instrument thereby performing much like a smallPAsystem.

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