BOSS AC-3 AC-3.pdf

Owner’s Manual

Before using this unit, carefully read the sections entitled: “USING THE UNIT SAFELY”
and “IMPORTANT NOTES” (supplied on a separate sheet).

After reading, keep the document(s) where it will be available for immediate
reference.

English

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7

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5

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7 Eects processor utilizes COSM technology to transform electric

guitar input into beautiful acoustic guitar sounds.

7 MODE knob allows you to select from a choice of four dierent

acoustic guitar characters (tones).

7 Features two types of output jacks, one for guitar amps and

another for line out jacks, providing you with outputs suited to

the connected device.

7 “BODY” and “TOP” knobs can be used to adjust the acoustic

guitar’s characteristic body resonance and harmonics, allowing

you to produce a wide variety of tones.

7 Includes high-quality reverb developed exclusively for the AC-3.

Panel DescriptionsMain Features

COSM (Composite Object Sound Modeling)

Composite Object Sound Modeling (COSM) is BOSS/Roland’s
innovative and powerful sound modeling technology.

COSM analyzes the many factors that make up the original sound,
such as the electrical and physical characteristics of the original, and
then produces a digital model that can reproduce the same sound.

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1. AC Adaptor jack

Accepts connection of an AC Adaptor (optionally available BOSS
PSA-series).

By using an AC Adaptor, you can play without being concerned
about how much battery power you have left.

* If there are batteries in the unit while an AC adaptor is being

used, normal operation will continue should the line voltage
be interrupted (power blackout or power cord disconnection).

* Use only the specied AC adaptor (PSA-series).

2. CHECK indicator

This indicator shows whether an eect is ON/OFF, and doubles
as the Battery Check indicator.

The indicator lights when an eect is ON.

* If this indicator goes dim or no longer lights while an eect

is ON, the battery is near exhaustion and should be replaced
immediately. For instructions on changing the battery, refer
to “Changing the Battery” (p. 13).

* The CHECK indicator shows whether the eect is on or o, and

indicates the dierent functions. It does not indicate whether
the power to the device is on or not.

Panel Descriptions

3. LINE OUT jack

This output jack is used for connecting to mixers, recorders, and
other devices that accept line-level input.

When a cable is also connected to the G.AMP OUT jack, the
output is sent from the LINE OUT jack when the eect is
switched on, while the output is muted when the eect is
switched o.

For details, refer to “Connections” (p. 6–p. 11).

4. G.AMP (Guitar Amp) OUT jack

This output jack is used for connecting to guitar amps and other
eects processors.

The eect sound or direct sound is output from here depending
on whether the eect is switched on or o.

When a cable is simultaneously connected to the LINE OUT jack,
the output from the G.AMP OUT jack is muted when the eect
is switched on, while the direct sound is output when the eect
is switched o.

For details, refer to “Connections” (p. 6–p. 11).

5. Pedal switch

This switch turns the eects on/o.

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Panel Descriptions

11 12

8 9

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6. Thumbscrew

When this screw is loosened, the pedal will open, allowing you
to change the battery.

* For instructions refer to “Changing the Battery” (p. 13).

7. INPUT jack

This jack accepts input signals (coming from an electric guitar,
some other musical instrument, or another eects unit).

* The INPUT jack doubles as power switch.

Power to the unit is turned on when you plug into the INPUT
jack; the power is turned o when the cable is unplugged.
When not using the eects unit, be sure to disconnect the
plug from the INPUT jack.

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8. REVERB knob

This adjusts the amount of reverb applied to the sound.

9. LEVEL knob

This adjusts the volume of the eect sound.

10. BODY knob

This adjusts the resonance of the sound produced by the guitar
body, altering the characteristic mellowness and breadth of the
acoustic guitar sound.

11. TOP knob

This adjusts the sense of attack and the harmonic content of the
upper range.

12. MODE knob

Provides for selection of the tone. The knob can be used to
select any of four tones.

STANDARD

JUMBO

ENHANCE

PIEZO

This tone is that of the popular Dreadnought
acoustic guitar body style.

This setting provides a tone characteristic of
an oversized guitar body, a tone featuring
a rich bass response along with a beautiful
high end.

Providing a sharper attack than the standard
tone, this tone does not become masked
by the sounds of other instruments, even in
bands and ensembles.

This setting provides the tone of a round­back acoustic guitar, with subdued body
resonance and a unique attack.

English

Panel Descriptions

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Connections

* Power is turned on whenever a plug is inserted into the INPUT

jack.

* Raise the amp volume only after turning on the power to all

connected devices.

* The use of an AC adaptor is recommended as the unit’s power

consumption is relatively high. Should you prefer to use
batteries, please use the alkaline type.

* To prevent malfunction and equipment failure, always turn

down the volume, and turn o all the units before making any
connections.

* We recommend that you keep batteries installed in the unit

even though you’ll be powering it with the AC adaptor. That
way, you’ll be able to continue a performance even if the
cord of the AC adaptor gets accidentally disconnected from
the unit.

* Once the connections have been completed, turn on power

to your various devices in the order specied. By turning on
devices in the wrong order, you risk causing malfunction and/
or damage to speakers and other devices.

When powering up:

Turn on the power to your guitar amp last.

When powering down:

Turn o the power to your guitar amp rst.

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* Before turning the unit on/o, always be sure to turn the

volume down. Even with the volume turned down, you might
hear some sound when switching the unit on/o. However,
this is normal and does not indicate a malfunction.

* When operating on battery power only, the unit’s indicator

will become dim when battery power gets too low. Replace
the battery as soon as possible.

* If you handle batteries improperly, you risk explosion and

uid leakage. Make sure that you carefully observe all of the
items related to batteries that are listed in “USING THE UNIT
SAFELY” and “IMPORTANT NOTES.”

NOTE (Placement)

Depending on the material and temperature of the surface on
which you place the unit, its bottom cover (rubber) may discolor
or mar the surface. You can place a piece of felt or cloth under
the bottom cover to prevent this from happening.

If you do so, please make sure that the unit will not slip or move
accidentally.

When Connecting to a Guitar Amp

AC Adaptor
BOSS PSA-series
(sold separately)

English

Connections

Guitar Amplier

OUT 9V DC/500 mA

Multiple Eects, etc.

Electric Guitar

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Connections

When Connecting to a PA System, Recorder, or Similar Equipment

PA System

AC Adaptor
BOSS PSA-series
(sold separately)

Electric Guitar

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Recorder

Connections

When Connecting Both to a Guitar Amp and PA System (or Recorder or Similar Equipment)

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With Eect On

The CHECK indicator lights, the output from the AC-3: G.AMP OUT jack is muted, and the eect sound is output from the LINE OUT jack.

AC Adaptor
BOSS PSA-series
(sold separately)

PA System

Eect sound

Electric Guitar

English

Guitar Amplier

Recorder

Multiple Eects, etc.

Mute

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Connections

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With Eect O

The CHECK indicator is o, the guitar sound (with eect o) is output from the AC-3: G.AMP OUT jack, and the output from the LINE OUT jack
is muted.

AC Adaptor
BOSS PSA-series
(sold separately)

PA System

Electric Guitar

Recorder

Mute

Guitar sound

(Direct sound)

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Guitar Amplier

Multiple Eects, etc.

The following shows the correspondence between output jack connection status and the sound output.

Output from LINE OUT Output from G.AMP OUT

Eects On Eects O Eects On Eects O

English

Connections

Both LINE OUT and

G.AMP OUT Connected

Only

LINE OUT

Connected

Only

G.AMP OUT

Connected

Eect Sound

(Line)

Eect Sound

(Line)

- -

Mute Mute Direct Sound

Direct Sound - -

Eect Sound

(for Guitar Amp)

Direct Sound

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Operating the Unit

1. When you have made the necessary connections
(p. 6–p. 11), set the knobs as shown in the
illustration.

2. Depress the pedal switch to turn the eect on.

(Make sure that the CHECK indicator lights.)

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3. Select the mode with the MODE knob.

4. Adjust the harmonic content with the TOP knob.

* If the sound is distor ted, adjust by turning the TOP knob to

the left (counterclockwise).

* Distortion can also be suppressed by turning the LEVEL knob

to the left.

5. Adjust the breadth of the sound with the BODY knob.

6. Using the LEVEL knob, adjust the balance of the

volume for when the eects are on and when o.

7. Adjust the amount of reverb with the REVERB knob.

Changing the Battery

When the indicator goes dim or no longer lights while an eect
is on, it means that the battery is nearly dead and must be
replaced. Replace the battery following the steps below.

* The use of an AC adaptor is recommended as the unit’s power

consumption is relatively high. Should you prefer to use
batteries, please use the alkaline type.

Thumbscrew

Battery Snap
Cord

Battery Snap

Battery Housing

9 V Battery

Pedal

Spring Base

Coil Spring

Guide Bush
Hole

1. Loosen the thumbscrew at the front of the pedal,
then lift the pedal upwards to open the unit.

The thumbscrew can be left in the pedal while changing the
battery.

2. Remove the old battery from the battery housing,
and remove the snap cord connected to it.

3. Connect the snap cord to the new battery, and place
the battery inside the battery housing.

* Be sure to carefully observe the battery ’s polarity (+ versus -).

4. Slip the coil spring onto the spring base on the back

of the pedal, and then close the pedal.

* Carefully avoid getting the snap cord caught in the pedal, coil

spring, and battery housing.

5. Finally, insert the thumbscrew into the guide bush
hole and fasten it securely.

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Setting Samples

Finger Picking

(Single coil, front pickup)

Chord Stroke

(Single coil, front pickup)

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Solo Phrase

(Single coil, front pickup)

Humbucking Setting

(Humbucking, front pickup)

Main Specications

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AC-3: Acoustic Simulator

Nominal Input Level

Input Impedance

Nominal Output
Level

Output Impedance

Recommended Load
Impedance

Power Supply

Current Draw

Dimensions

Weight

-20 dBu

1 MΩ

-20 dBu

1 kΩ

10 kΩ or greater

DC 9 V:

Dry battery/9 V type (6LR61 (alkaline)),
AC Adaptor (PSA-series: optional)

45 mA (DC 9 V)

* Expec ted battery life under

continuous use:
Alkaline: 7.5 hours
These gures will vary depending on
the actual conditions of use.

73 (W) x 129 (D) x 59 (H) mm
2-7/8 (W) x 5-1/8 (D) x 2-3/8 (H) inches

440 g / 1 lb (including battery)

Owner’s Manual, Leaet (“USING THE
UNIT SAFELY,” “IMPORTANT NOTES,” and
“Information”), Dry battery/9 V type

Accessories

Options

* 0 dBu = 0.775 Vrms

* This document explains the specications of the product

at the time that the document was issued. For the latest
information, refer to the Roland website.

(6LR61)

* The batter y that was supplied with

the unit is for temporary use intended
primarily for testing its operation. We
also suggest replacing this with an
alkaline dry cell.

AC Adaptor (PSA-series)

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Copyright © 2018 ROLAND CORPORATION