Roland AC-40 - Acoustic Chorus Guitar Amplifier Manual

Panel Descriptions

Control Panel (Connecting Your Guitar/Microphone)

1. GUITAR CHANNEL
   • INPUT jack - Connect your guitar here.
   • [VOLUME] knob - This adjusts the volume of the guitar channel.
   • [BASS] knob - This adjusts the sound level of the low-frequency range.
   • [MIDDLE] knob - This adjusts the sound level of the mid-frequency range.
   • [TREBLE] knob - This adjusts the sound level of the high-frequency range.
   • [CHORUS] knob - This switches the type of chorus that is applied.
   • [REVERB] knob - This adjusts the amount of reverb.
2. MIC/LINE CHANNEL
   • INPUT jack - Connect your microphone or line-level device here.
     You can use any one of three types of plugs (XLR, TRS, phone).
     * If your guitar has a pickup as well as a builtin preamp, you can also connect it to the MIC/LINE CHANNEL.
     
     * This instrument is equipped with balanced (XLR/TRS) type jacks. Wiring diagrams for these jacks are shown below. Make connections after first checking the wiring diagrams of other equipment you intend to connect.
     
     * Phantom power is not supplied.
   • [VOLUME] knob - This adjusts the volume of the mic/line channel. If you're using a microphone, set this to the MIC position.
   • [BASS] knob - This adjusts the sound level of the low-frequency range.
   • [MIDDLE] knob - This adjusts the sound level of the mid-frequency range.
   • [TREBLE] knob - This adjusts the sound level of the high-frequency range.
   • [CHORUS] knob - This switches the type of chorus that is applied.
   • [REVERB] knob - This adjusts the amount of reverb.
3. [MASTER] knob
   This adjusts the overall volume.
   * This knob does not affect LINE OUT.
4. [ANTI-FEEDBACK] switch
   You can prevent acoustic feedback by turning this on.
   * When you turn this switch on, the feedback point will be detected automatically.
   * The next time you turn on the power, the setting for the feedback point that was automatically detected will be reset.
5. POWER indicator
   This will light if the power is on.
6. [POWER] switch
   This turns the power on/off.

Jack Panel (Connecting Your Equipment)

NOTE

• To prevent malfunction and equipment failure, always turn down the volume, and turn off all the units before making any connections.
• When connection cables with resistors are used, the volume level of equipment connected to the inputs (GUITAR CHANNEL, MIC/LINE CHANNEL, AUX IN) may be low. If this happens, use connection cables that do not contain resistors.

7. DC IN jack
   Connect the included AC adaptor here.
   
   * You must use only the AC adaptor that is supplied with the AC-40.
8. PHONES jack
   Connect headphones equipped with a stereo mini-plug.
   
9. LINE OUT jacks
   You can connect your mixer or recorder here. Connect to the L/MONO jack if you're outputting in mono. * The [MASTER] knob does not affect the output from the LINE OUT jacks.
   
10. AUX IN jack/[LEVEL] knob
    Use the stereo mini-cable to connect your CD player or digital audio player here.
    Use the [LEVEL] knob to adjust the volume.
    
    * The chorus/reverb is not applied to AUXIN jack.
11. FOOT SW jack
    If footswitches are connected, you'll be able to control the turn effects on/off using your foot.
    * You'll need momentary-type footswitches (BOSS FS-5U or FS-6; sold separately).
    

• Chorus on/off and Reverb on/off operations apply in common to the GUITAR CHANNEL and the MIC/LINE CHANNEL.
• If the [CHORUS] switch is "OFF" or if the [REVERB] knob is at 0, you won't be able to turn chorus or reverb on/off by operating the footswitch.
• If you use a phone plug (mono) cable to connect only one footswitch, it will only turn chorus on/off.
  
  Set the polarity switch of the footswitches as shown in the illustration.
  

Operation

Turning the Power On/Off

Once everything is properly connected, be sure to follow the procedure below to turn on their power. If you turn on equipment in the wrong order, you risk causing malfunction or equipment failure.

1. Make sure that the power to all equipment is turned off.
2. Set each of the AC-40's [VOLUME] knobs and the [MASTER] knob to 0.
   
3. Switch on the power to any external equipment connected to the AUX IN jack.
4. Switch on the AC-40's power.
   
   * This unit is equipped with a protection circuit. A brief interval (a few seconds) after turning the unit on is required before it will operate normally.
5. Switch on any equipment connected to the LINE OUT jacks.
6. When you want to turn the power off, minimize the volume on the AC-40 and all connected devices, and then turn off their power in the opposite order of that followed when turning them on.
   * Before turning the unit on/off, always be sure to turn the volume down. Even with the volume turned down, you might hear some sound when switching the unit on/off. However, this is normal and does not indicate a malfunction.

Using Effects

Chorus and reverb are provided for both the Guitar channel and the Mic/Line channel.
You can adjust the effect depth individually for each channel.

Applying Chorus

1. Set each channel's [CHORUS] switch to "WIDE" or "SPACE" position.
   

* If the [CHORUS] switch is "OFF," you won't be able to turn chorus on/off by operating the footswitch.

Applying Reverb

This is a stereo reverb that was developed specifically for acoustic instruments and produces a spacious and natural sound.

1. Use the [REVERB] knob to adjust the depth.
   
   * If the [REVERB] knob is at 0, you won't be able to turn reverb on/ off by operating the footswitch.

Using the Anti-Feedback Function

What is acoustic feedback?
This is an unpleasant oscillation (a whine, buzz, or howl) that occurs when the output from a speaker is re-input to a microphone or pickup, amplified, and output again from the speaker.
This is more likely to occur when you point the microphone at a speaker or raise the volume to a high level.

What is the anti-feedback function?
This function suppresses the acoustic feedback that can occur between a guitar or microphone and the amp. It does this by attenuating the sound in the frequency range at which feedback is occurring.
Feedback will be suppressed automatically when you use the antifeedback function.

1. Turn the [ANTI-FEEDBACK] switch "ON."
   
   When you turn the switch "ON," the feedback point (frequency) will be detected automatically.
   The anti-feedback function will be applied to the microphone or guitar connected to the GUITAR CHANNEL and MIC/LINE CHANNEL inputs.

MEMO
In order to prevent feedback from occurring during your performance, we recommend that you turn the anti-feedback function ON before you begin performing.

NOTE

• The next time you turn on the power, the setting for the feedback point that was automatically detected will be reset.
• If the anti-feedback function is not enough to suppress feedback, take the following steps.
  • Change the direction of the guitar or microphone
  • Move the guitar or microphone away from the speakers
  • Lower the volume

Using the Arm Stand

When using the AC-40 at a low position such as on the floor, extending the arm stand will make the sound from the speakers easier to hear.

NOTE

• When using the arm stand, please observe the following points.
  • You must place the AC-40 on a horizontal surface.
  • Do not place objects on the AC-40, or sit or stand on the AC-40.
  • Do not lift or carry the AC-40 by grasping its arm stand.
• Fold the arm stand if you're not using it.
• When deploying or retracting the arm stand, be careful so as not to get your fingers pinched between the movable part and the unit itself. In places where small children are present, make sure that an adult provides supervision and guidance.

Various Ways to Use the AC-40

Singer/Performer

You can sing while playing your guitar.

• Connect your guitar to the GUITAR CHANNEL.
• Connect your microphone to the MIC/LINE CHANNEL.
  

Guitar Duo

Here's how two guitarists can perform.

• Connect one guitar to the GUITAR CHANNEL.
• Connect the other guitar (with a built-in preamp) to the MIC/LINE CHANNEL.
  

Miking Your Instrument

You can use a microphone to input sound from an instrument that is not equipped with a pickup.

• Connect your microphone to the MIC/LINE CHANNEL.
• Point the microphone toward the instrument.
  
  * The AC-40 is not equipped to provide phantom power, so condenser microphones that require phantom power cannot be used.

Blending Sound from Two Types of Pickups

If your guitar has two types of pickups, you can use the AC-40 to mix their outputs.

• Connect the pickup attached to the sound hole of your guitar to the GUITAR CHANNEL input.
• Connect the pickup (with internal preamp) built into your guitar to the MIC/LINE CHANNEL input.
  

Troubleshooting

If the system does not work as you expect, check the following points first.

Block Diagram

Specifications

Roland AC-40: ACOUSTIC GUITAR AMPLIFIER

* 0 dBu=0.775 Vrms
* In the interest of product improvement, the specifications and/or appearance of this unit are subject to change without prior notice.

USING THE UNIT SAFELY

THIS APPARATUS MUST BE EARTHED

THE WIRES IN THIS MAINS LEAD ARE COLOURED IN ACCORDANCE WITH THE FOLLOWING CODE. GREEN-AND-YELLOW: EARTH, BLUE: NEUTRAL, BROWN: LIVE

As the colours of the wires in the mains lead of this apparatus may not correspond with the coloured markings identifying the terminals in your plug, proceed as follows:
The wire which is coloured GREEN-AND-YELLOW must be connected to the terminal in the plug which is marked by the letter E or by the safety earth symbol or coloured GREEN or GREEN-AND-YELLOW.

The wire which is coloured BLUE must be connected to the terminal which is marked with the letter N or coloured BLACK. The wire which is coloured BROWN must be connected to the terminal which is marked with the letter L or coloured RED.

Before using this unit, carefully read the sections entitled "USING THE UNIT SAFELY" and "IMPORTANT NOTES". These sections provide important information concerning the proper operation of the unit. Additionally, in order to feel assured that you have gained a good grasp of every feature of your new unit, read Owner's manual in its entirety. This manual should be saved and kept on hand as a convenient reference.

INSTRUCTIONS FOR THE PREVENTION OF FIRE, ELECTRIC SHOCK, OR INJURY TO PERSONS

About WARNING and CAUTION Notices

Used for instructions intended to alert the user to the risk of death or severe injury should the unit be used improperly.

Used for instructions intended to alert the user to the risk of injury or material damage should the unit be used improperly.

* Material damage refers to damage or other adverse effects caused with respect to the home and all its furnishings, as well to domestic animals or pets.

About the Symbols

The symbol alerts the user to important instructions or warnings. The specific meaning of the symbol is determined by the design contained within the triangle. In the case of the symbol at left, it is used for general cautions, warnings, or alerts to danger.

The symbol alerts the user to items that must never be carried out (are forbidden). The specific thing that must not be done is indicated by the design contained within the circle. In the case of the symbol at left, it means that the unit must never be disassembled.

The symbol alerts the user to things that must be carried out. The specific thing that must be done is indicated by the design contained within the circle. In the case of the symbol at left, it means that the power-cord plug must be unplugged from the outlet.

ALWAYS OBSERVE THE FOLLOWING

Make sure that the power cord is grounded

Connect mains plug of this model to a mains socket outlet with a protective earthing connection.

To completely turn off power to the unit, pull out the plug from the outlet

Even with the power switch turned off, this unit is not completely separated from its main source of power. When the power needs to be completely turned off, turn off the power switch on the unit, then pull out the plug from the outlet. For this reason, the outlet into which you choose to connect the power cord's plug should be one that is within easy reach and readily accessible.

Do not disassemble or modify by yourself

Do not open (or modify in any way) the unit or its AC adaptor.

Do not repair or replace parts by yourself

Do not attempt to repair the unit, or replace parts within it (except when this manual provides specific instructions directing you to do so). Refer all servicing to your retailer, the nearest Roland Service Center, or an authorized Roland distributor, as listed on the "Information" page.

Do not use or store in the following types of locations

• Subject to temperature extremes (e.g., direct sunlight in an enclosed vehicle, near a heating duct, on top of heatgenerating equipment); or are
• Damp (e.g., baths, washrooms, on wet floors); or are
• Exposed to steam or smoke; or are
• Subject to salt exposure; or are
• Humid; or are
• Exposed to rain; or are
• Dusty or sandy; or are
• Subject to high levels of vibration and shakiness.

Do not place in an unstable location

Make sure you always have the unit placed so it is level and sure to remain stable. Never place it on stands that could wobble, or on inclined surfaces.

Use only the supplied AC adaptor and the correct voltage

Be sure to use only the AC adaptor supplied with the unit. Also, make sure the line voltage at the installation matches the input voltage specified on the AC adaptor's body. Other AC adaptors may use a different polarity, or be designed for a different voltage, so their use could result in damage, malfunction, or electric shock.

Use only the supplied power cord

Use only the attached power-supply cord. Also, the supplied power cord must not be used with any other device.

Do not bend the power cord or place heavy objects on it

Do not excessively twist or bend the power cord, nor place heavy objects on it. Doing so can damage the cord, producing severed elements and short circuits. Damaged cords are fire and shock hazards!

Avoid extended use at high volume

This unit, either alone or in combination with an amplifier and headphones or speakers, may be capable of producing sound levels that could cause permanent hearing loss. Do not operate for a long period of time at a high volume level, or at a level that is uncomfortable. If you experience any hearing loss or ringing in the ears, you should immediately stop using the unit, and consult an audiologist.

Don't allow foreign objects or liquids to enter unit; never place containers with liquid on unit

Do not place containers containing liquid (e.g., flower vases) on this product. Never allow foreign objects (e.g., flammable objects, coins, wires) or liquids (e.g., water or juice) to enter this product. Doing so may cause short circuits, faulty operation, or other malfunctions.

Turn off the unit if an abnormality or malfunction occurs

Immediately turn the unit off, remove the AC adaptor from the outlet, and request servicing by your retailer, the nearest Roland Service Center, or an authorized Roland distributor, as listed on the "Information" page when:

• The AC adaptor, the power-supply cord, or the plug has been damaged; or
• If smoke or unusual odor occurs; or
• Objects have fallen into, or liquid has been spilled onto the unit; or
• The unit has been exposed to rain (or otherwise has become wet); or
• The unit does not appear to operate normally or exhibits a marked change in performance.

Adults must provide supervision in places where children are present

Always make sure that an adult is on hand to provide supervision and guidance when using the unit in places where children are present.

Do not drop or subject to strong impact

Protect the unit from strong impact. (Do not drop it!)

Do not share an outlet with an unreasonable number of other devices

Do not force the unit's power-supply cord to share an outlet with an unreasonable number of other devices. Be especially careful when using extension cords—the total power used by all devices you have connected to the extension cord's outlet must never exceed the power rating (watts/amperes) for the extension cord. Excessive loads can cause the insulation on the cord to heat up and eventually melt through.

Do not use overseas

Before using the unit in overseas, consult with your retailer, the nearest Roland Service Center, or an authorized Roland distributor, as listed on the "Information" page.

Place in a well ventilated location

The unit and the AC adaptor should be located so their location or position does not interfere with their proper ventilation.

When disconnecting an AC adaptor, grasp it by the plug

To prevent conductor damage, always grasp the AC adaptor by its plug when disconnecting it from this unit or from a power outlet.

Periodically clean the AC adaptor's plug

At regular intervals, you should unplug the AC adaptor and clean it by using a dry cloth to wipe all dust and other accumulations away from its prongs. Also, disconnect the power plug from the power outlet whenever the unit is to remain unused for an extended period of time. Any accumulation of dust between the power plug and the power outlet can result in poor insulation and lead to fire.

Manage cables for safety

Try to prevent cords and cables from becoming entangled. Also, all cords and cables should be placed so they are out of the reach of children.

Avoid climbing on top of the unit, or placing heavy objects on it

Never climb on top of, nor place heavy objects on the unit.

Do not connect or disconnect the AC adaptor with wet hands

Never handle the AC adaptor or its plugs with wet hands when plugging into, or unplugging from, an outlet or this unit.

Disconnect everything before moving the unit

Before moving the unit, disconnect the AC adaptor and all cords coming from external devices.

Unplug the AC adaptor from the outlet before cleaning

Before cleaning the unit, turn it off and unplug the AC adaptor from the outlet.

If there is a possibility of lightning strike, disconnect the AC adaptor from the outlet

Whenever you suspect the possibility of lightning in your area, disconnect the AC adaptor from the outlet.

Take care so as not to get fingers pinched

Arm stand
When handling the following moving parts, take care so as not to get fingers, toes, etc., pinched. Whenever a child uses the unit, an adult should be on hand to provide supervision and guidance.

IMPORTANT NOTES

Power Supply

• Do not connect this unit to same electrical outlet that is being used by an electrical appliance that is controlled by an inverter or a motor (such as a refrigerator, washing machine, microwave oven, or air conditioner). Depending on the way in which the electrical appliance is used, power supply noise may cause this unit to malfunction or may produce audible noise. If it is not practical to use a separate electrical outlet, connect a power supply noise filter between this unit and the electrical outlet.
• The AC adaptor will begin to generate heat after long hours of consecutive use. This is normal, and is not a cause for concern.
• To prevent malfunction and equipment failure, always make sure to turn off the power on all your equipment before you make any connections.

Placement

• Using the unit near power amplifiers (or other equipment containing large power transformers) may induce hum. To alleviate the problem, change the orientation of this unit; or move it farther away from the source of interference.
• This device may interfere with radio and television reception. Do not use this device in the vicinity of such receivers.
• Noise may be produced if wireless communications devices, such as cell phones, are operated in the vicinity of this unit. Such noise could occur when receiving or initiating a call, or while conversing. Should you experience such problems, you should relocate such wireless devices so they are at a greater distance from this unit, or switch them off.
• Do not expose the unit to direct sunlight, place it near devices that radiate heat, leave it inside an enclosed vehicle, or otherwise subject it to temperature extremes. Also, do not allow lighting devices that normally are used while their light source is very close to the unit (such as a piano light), or powerful spotlights to shine upon the same area of the unit for extended periods of time. Excessive heat can deform or discolor the unit.
• When moved from one location to another where the temperature and/or humidity is very different, water droplets (condensation) may form inside the unit. Damage or malfunction may result if you attempt to use the unit in this condition. Therefore, before using the unit, you must allow it to stand for several hours, until the condensation has completely evaporated.
• Do not allow rubber, vinyl, or similar materials to remain on this unit for long periods of time. Such objects can discolor or otherwise harmfully affect the finish.
• Do not paste stickers, decals, or the like to this instrument. Peeling such matter off the instrument may damage the exterior finish.
• Depending on the material and temperature of the surface on which you place the unit, its rubber feet may discolor or mar the surface. You can place a piece of felt or cloth under the rubber feet to prevent this from happening. If you do so, please make sure that the unit will not slip or move accidentally.
• Do not place containers or anything else containing liquid on top of this unit. Also, whenever any liquid has been spilled on the surface of this unit, be sure to promptly wipe it away using a soft, dry cloth.

Maintenance

• For everyday cleaning wipe the unit with a soft, dry cloth or one that has been slightly dampened with water. To remove stubborn dirt, use a cloth impregnated with a mild, non-abrasive detergent. Afterwards, be sure to wipe the unit thoroughly with a soft, dry cloth.
• Never use benzine, thinners, alcohol or solvents of any kind, to avoid the possibility of discoloration and/or deformation.

Additional Precautions

• Use a reasonable amount of care when using the unit's buttons, sliders, or other controls; and when using its jacks and connectors. Rough handling can lead to malfunctions.
• When disconnecting all cables, grasp the connector itself—never pull on the cable. This way you will avoid causing shorts, or damage to the cable's internal elements.
• To avoid disturbing others nearby, try to keep the unit's volume at reasonable levels.
• When you need to transport the unit, package it in the box (including padding) that it came in, if possible. Otherwise, you will need to use equivalent packaging materials.
• Some connection cables contain resistors. Do not use cables that incorporate resistors for connecting to this unit. The use of such cables can cause the sound level to be extremely low, or impossible to hear. For information on cable specifications, contact the manufacturer of the cable.
• When deploying or retracting the arm stand, be careful so as not to get your fingers pinched between the movable part and the unit itself. In places where small children are present, make sure that an adult provides supervision and guidance.

Documents / Resources

Download manual

Here you can download full pdf version of manual, it may contain additional safety instructions, warranty information, FCC rules, etc.

Download Roland AC-40 - Acoustic Chorus Guitar Amplifier Manual