AT3300 SERIES CLASS AB

2 TO 8-CHANNEL POWER AMPLIFIER

OWNER’S GUIDE

AT3300 Manual Rev-11/21

PLEASE READ FIRST

CAUTION: To reduce the risk of electrical shock, do not remove the cover (or back). No user serviceable parts inside.

Refer servicing to qualified service personnel.

WARNING: To reduce the risk of fire or electric shock, do not expose this appliance to rain or moisture.

The lightning flash with arrowhead, within an equilateral triangle, is intended to alert the user to the presence of uninsulated “dangerous voltage” within the product’s enclosure that may be of sufficient magnitude to constitute a risk of electrical shock to persons.

The exclamation point within an equilateral triangle is intended to alert the user to the presence of important operation maintenance

(servicing) instructions in the literature accompanying the appliance.

California Proposition 65 Warning: This product may contain chemicals known to the State of California to cause cancer, or birth defects or other reproductive harm. (California law requires this warning to be given to customers in the

State of California.)

PRECAUTIONS

The AT3300 amplifier is a wide-band design with substantial power output capability. Certain precautions must be taken to ensure proper operation.

1. Never expose the amplifier to moisture.

2. Never plug an input cable into the amplifier while the unit is turned on.

3. Never apply the “thumb test” (touching the “hot” lead of the input cable with your finger) to the tip of the input cable or input jack of the ATI amplifier. RF rectification and/or hum will be created and could cause damage to the loudspeakers. ATI will not be responsible for damage to the loudspeakers due to improper use of the equipment.

4. Under no circumstances should the output terminals of the AT3300 be short-circuited.

5. Avoid restricting the airflow around the AT3300 amplifier. Good airflow is necessary to ensure proper cooling and trouble-free operation.

6. Ensure that the rated power handling of the loudspeakers connected to the AT3300 amplifier can handle the output power of the amplifier. The warranty of the AT3300 does not cover damage to loudspeakers with inadequate power handling capability.

7. Do not stack other system components or any other materials on top of the AT3300 amplifier. The amplifier is

Hybrid fan & convection cooled and air must be free to circulate around its chassis.

SAFETY INSTRUCTIONS

Read all the safety and operating instructions before connection or using the AT3300 amplifier.

All warnings on the unit and in this operating manual should be adhered to.

All operating and use instructions should be followed.

Do not place/use the unit near water; for example, near a bathtub, washbowl/sink, laundry tub, decorative water features (waterfalls/fountains), in a wet basement or near a swimming pool.

This unit is not intended for outdoor use.

This unit should be installed so that its location or position does not interfere with its proper ventilation. For example, it should not be situated on a bed, sofa, rug or similar surface that may block its ventilation openings. It should also not be placed in a built-in enclosure, such as bookcase or cabinet, that may impede the flow of air through its ventilation openings.

The unit should be situated away from heat sources such as radiators, fireplaces, hot air ducts, heat registers, stoves and/ or other devices (including amplifiers) that produce heat.

The unit should be connected to a power-supply outlet only of the voltage and frequency marked on its rear panel.

The AC power cord should be routed so that it is not likely to be walked on or pinched, especially near the plug, convenience receptacles or where the cord exits from the unit.

Clean the unit only as recommended in this instruction manual.

The unit’s AC power cord should be unplugged from the wall outlet when the unit is to be unused for a long period of time.

Care should be taken so that objects do not fall, and liquids are not spilled, into the unit through any openings.

The unit should be serviced by qualified service personnel only when:

A. The power cord or plug has been damaged; or

B. Objects have fallen, or liquid has been spilled, into the unit; or

C. The unit has been exposed to rain or liquids of any kind; or

D. The unit does not appear to operate normally or exhibits a marked change in performance; or

E. The device has been dropped or the enclosure damaged.

To prevent electric shock, do not use a ground lift plug/ adapter. Also, do not use the polarized plug with an extension cord, receptacle or other outlet unless all the blades can be fully inserted to prevent blade exposure.

AT3300 Manual 1 Rev-11/21

Table of Contents

SAFETY WARNING

.........................................................................................................................

1

SAFETY INSTRUCTIONS ............................................................................................................... 1

Table of Contents ................................................................................................................................. 2

AT3300 Identification Record ............................................................................................................. 2

Introduction .......................................................................................................................................... 3

Features and Testing............................................................................................................................. 3

Unpacking ............................................................................................................................................ 3

Placement ............................................................................................................................................. 3

Rack Mounting ..................................................................................................................................... 4

Owner’s Guide Conventions ................................................................................................................ 4

Front Panel Layout ............................................................................................................................... 4

Rear Panel Layout ................................................................................................................................ 5

Amplifier Channel to Speaker Map ..................................................................................................... 5

Connecting Your Amplifier ................................................................................................................. 6

Input Connections ................................................................................................................................ 6

Speaker Connections ............................................................................................................................ 6

Power Control Connections ................................................................................................................. 7

AC Power Connections & Cords ......................................................................................................... 7

Amplifier Operation ............................................................................................................................. 8

Manual On ............................................................................................................................................ 8

Automatic On ....................................................................................................................................... 8

ATI Service Information ...................................................................................................................... 8

Care and Maintenance .......................................................................................................................... 8

A Few Words About Hum and Noise .................................................................................................. 8

Potential Ground Loops in a Complex A/V System ........................................................................... 9

Errors and Omissions Statement .......................................................................................................... 9

Appendix A - Troubleshooting Guide ................................................................................................ 10

Appendix B - Model Circuit Breaker Ratings .................................................................................... 10

Appendix C - Specifications .............................................................................................................. 11

Appendix D - Power Requirements & Consumption ......................................................................... 12

Appendix E - Thermal Dissipation..................................................................................................... 12

Appendix F - AT3300 Family Rear Panel Views .............................................................................. 13

Warranty Information ......................................................................................................................... 14

Amplifier Identification Record

This information is for your records and for future identification of the AT3300. Please take a moment to fill out all pertinent data now. Whenever inquiries and/or repairs are requested, the serial number will be required.

MODEL NUMBER

SERIAL NUMBER

DATE PURCHASED

DEALER’S NAME

DEALER’S ADDRESS/PHONE

AT3300 Manual 2 Rev-11/21

AT3300 Series Power Amplifiers

Congratulations! Thank you for purchasing an ATI

AT3300 Power Amplifier, one of the most advanced audio components available. Designed, engineered and assembled in the United States, it has been carefully designed and tested to deliver the best possible audiophile-grade performance as well as the most reliable operation.

The AT3300 Series is comprised of seven models; the last digit in the model number is the number of channels in the amplifier. This manual covers all seven models.

In order to receive the maximum performance from your new amplifier, please take a few minutes to read this manual. This important information will help you make certain that the amplifier is properly configured for operation with the rest of the equipment in your system.

If you have any questions about this product, its installation or operation, please contact us via e-mail at [email protected] or via telephone at 323-278-0001.

Features and Testing

Your AT3300 amplifier was designed to provide a state

-of-the-art listening experience and is suitable for use with associated components of the highest order. Each module includes an ATI designed custom gain stage and linear power supply to deliver superior performance.

Additional features include:

 Custom soft-start circuitry to minimize any turn-on power surge;

 Complete protection from overload, DC faults, over-voltage or over-temperature conditions.

 Extruded aluminum heatsinks to cool the amplifier channels.

 Two computer grade 2000 RPM 140mm PWM fans, 1 per 4 channel module.

This AT3300 amplifier has been put through a rigorous and unique testing procedure ensuring that each amplifier will last for many years with minimal service requirements. This procedure includes the following:

 All assembled circuit boards are given a thorough visual inspection and are then performance tested.

 The tested, assembled circuit boards are then installed in a new AT3300 and the whole unit is tested for every function and parameter.

AT3300 Manual 3

 The unit is put on a burn-in torture rack to test for any possible component failures.

 The amplifier then undergoes a critical listening and final functional test.

Unpacking

Your amplifier is a precision electronic instrument and should be properly packaged any time shipment is made. The carton and packing materials used in shipping your new amplifier were specially designed to protect it from the shock and vibration of shipping. We strongly suggest that you save the carton and packing materials to use if you move, or if the unit ever needs to be shipped back to us for any reason. Should you discover that your amplifier has been damaged during shipping, please contact your dealer or ATI immediately and request the name of the carrier so a written claim may be made.

THE RIGHT TO A CLAIM AGAINST A PUBLIC

CARRIER CAN BE FORFEITED IF THE CARRIER

IS NOT NOTIFIED PROMPTLY IN WRITING AND

IF THE SHIPPING CARTON AND PACKING MA-

TERIALS ARE NOT AVAILABLE FOR INSPEC-

TION BY THE CARRIER. SAVE ALL PACKING

MATERIALS UNTIL THE CLAIM IS SETTLED.

Placement

During normal home operation the heat sinks on the amplifier will become warm. However, there are instances during high level playback into low impedance speakers when the heatsinks will become warmer than usual. To ensure the amplifier’s trouble-free operation, it is necessary to provide adequate ventilation for the heatsinks and fans. Your amplifier should be kept away from external sources of heat such as radiators and hotair ducts. The amplifier should never be placed with other heat-producing components in a cabinet or enclosure lacking free airflow. Do not stack other components directly on top of your amplifier.

NOTE : It is imperative that the amplifier be operated in a well-ventilated environment and that the immediate external temperature be maintained as specified.

NOTE : Since the AT3300 amplifiers use fans to aid in cooling, the height of the foot allows for sufficient space below the amplifier but additional space above the amplifier must be provided to allow for the fans to operate properly and quietly. A minimum of 1RU (1.75 inches) is recommended. When rack mounting the amplifier, additional space above and below the amplifier must be maintained. 1RU is recommended here as well and can be provided by blank or ventilated rack panels depending on the cooling design of the installation.

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Rack Mounting

The AT3300 Series amplifiers can be rack mounted into a standard 19-inch rack with the addition of rack ears. The kits are available separately for an additional charge and include instructions and hardware, if needed, for proper mounting of the parts to the amplifier.

To order, call your dealer or ATI and order SKU # /

Model “AB-RK33”.

Owner’s Guide Conventions

For clarity purposes, references to buttons and LED’s will be shown in bold capital letters.

Front Panel Layout

1

2

3

4

1. ATI LOGO.

2. PROTECT LED. Illuminates RED when any amplifier channel triggers a fault condition.

3. STANDBY LED. With the amplifier plugged in and the circuit breaker on the rear panel is “ON”, the amplifier is in standby mode and the STANDBY LED is illuminated amber. The STANDBY LED turns off when the amplifier is turned on and the standby supply has finished the turn-on process.

4. ILLUMINATED POWER SWITCH. When the amplifier is plugged in and in standby, the ILLUMINAT-

ED POWER SWITCH is off. When the ILLUMI-

NATED POWER SWITCH is depressed, the illumination of the switch becomes a constant blue, the

STANDBY LED remains illuminated and the amplifier begins the turn-on process. When the turn-on process is complete, the ILLUMINATED POWER SWITCH brightens fully, the STANDBY LED turns off and the amplifier begins playback.

AT3300 Manual 4 Rev-11/21

Rear Panel Layout

B

C

D

Above shows channel section 1-4. Channel section 5-8 is a mirror image. See Appendix F for complete view.

F G

H

I

J

A

E

A. Balanced (XLR) Audio Inputs

Connect the XLR outputs of the preamplifier or other source device via balanced XLR cables to the BALANCED INPUT jacks on the amplifier. The XLR jack is wired Pin 1 - Ground,

Pin 2 - Hot, and Pin 3 - Cold.

B. Unbalanced (RCA) Audio Inputs

Connect the RCA outputs of the preamplifier or other source device via unbalanced RCA cables to the UNBALANCED

INPUT jacks on the amplifier.

C. Input Selector Switches

Selects either the BALANCED INPUT (XLR) or the UN-

BALANCED INPUT (RCA) jack. Each channel has a switch, so you can mix inputs depending on your equipment.

D. Channel Name Label

ATI provides labels that use standard speaker location names to mark the amp and wires to make installation and debugging easier.

E. Speaker Outputs

Use the 5-way binding posts to connect the amplifier to your speakers. The posts with the red accents are positive. The posts with the black accents are negative.

F. Chassis Ground Terminal

Use to connect to other chassis where necessary.

G. Remote Trigger Input

Use the TRIGGER INPUT jack to connect to a compatible preamplifier, source device, or other product with a 3.3-24

VDC output.

H. Circuit Breakers / Mains Power Switches

These switches are also the over-current protection for the chassis. These operate like the circuit breakers in your houses electrical distribution box.

I. AC Inlets

The AT3300 amps include 1 or 2 IEC 60320 C20 inlets, depending on channel count. Use the included power cords to connect your amplifier to an AC power source.

J. Power Configuration Marking

Calls out AC voltage and frequency, circuit breaker trip current and power consumption. For a 120VAC configured amplifier, a green dot will be marked in the upper box. For a

240VAC configured amplifier, an orange dot will be marked in the lower box.

Amplifier Channel To Speaker Map

Source Channel Speaker Location Amplifier Channel

CHANNEL 1

CHANNEL 2

CHANNEL 3

CHANNEL 4

AT3300 Manual 5

Source Channel Amplifier Channel

CHANNEL 5

CHANNEL 6

CHANNEL 7

CHANNEL 8

Speaker Location

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Connecting Your Amplifier

When making connections between any source components and the amplifier, or when making connections to any speaker, be certain that both the input devices and the amplifier are turned off. To assure that there will be no unwanted signal transients that can damage equipment or speakers, it is always best to unplug all equipment before making any connections.

With the new multi-channel module design of the

AT3300 amplifiers and the renaming of each channel from actual speaker location to a just a number, we recommend using each module bank to power one side of the room, i.e. all of the left channel speakers are powered from the left amplifier bank and all the right channel speakers are powered from the right amplifier bank.

Then use the extra amplifier channel for the center channel speaker.

Input Connections

Connecting the amplifier to your source equipment is simple. Using high-quality audio interconnect cables, connect the outputs on the rear of your source equipment to the input jacks on the rear panel of your amplifier that have the same type of connector; any amplifier channel can be used to drive any loudspeaker in your room. The AT3300 amplifiers have both XLR and

RCA input connections on the rear panel. Use the slide switch below each RCA jack to select the desired input for each channel; you can mix input connections as needed. We do not recommend using this switch as another source selection. The switch actuator is flush with the rear panel, so a small tool may be needed to slide it to the proper position. When making connections with RCA type plugs on interconnect cables, make certain to gently, but firmly, insert the plug into the jack. Loose connections can cause intermittent sound and may damage your speakers. Some quality

RCA plugs may be very tight, and it is important to assure a proper connection between the interconnection cable and the input jack.

Speaker Connections

To assure that the high quality signals produced by your amplifier are carried to your speakers without loss of clarity or resolution, we recommend that you use high quality speaker wire. Many brands of wire are available; the choice may be influenced by the distance between your speakers and the amplifier, the type of speakers you use, personal preferences, or other factors.

Regardless of the brand or type of speaker wire selected, we recommend that you use a wire constructed of fine, multi-strand copper with a gauge of 14 or less. In specifying wire, the lower the number, the thicker the cable. Wire with a gauge of 16 may be used for short

AT3300 Manual 6 runs of less than twenty feet. We do not recommend that you use any wires with an AWG equivalent of 18 or higher due to the power loss and degradation in performance that will occur.

To connect the amplifier to your speakers, a pair of binding posts is provided for each channel output.

These posts will accept bare wire, spade lugs or banana type plugs. If bare wire is used for the connections, strip approximately 1/2 inch to 3/4 inch of insulation from the end of each wire and carefully twist the strands of each conductor together. Be careful not to cut the individual strands or twist them off. All strands must be used for optimal performance.

Correct polarity of connections are important to maintain proper speaker phasing. When speaker phasing is correct, all speakers move in and out at the same time, preserving the imaging of the program material. Out-of

-phase connections mean that some speaker cones will be moving in, while others move out. This will cause indistinct or confused imaging, and muddled and cloudy sounds. To avoid incorrect phasing or polarity, be certain to use wire that has distinct markings, colors, stripes, wording, or grooves on each side of the speaker cable. When making connections to the amp and speakers, adhere to a consistent pattern of using one side of the wire to the red terminals and the other side to the black terminals. When using cable with markings on one side only, traditional convention is to consider the marked side of the wire as the red, or positive (+) connection, and the non-marked side as the black or negative (–) connection.

Next, loosen the knobs of the amplifier’s speaker output terminals, far enough so that the pass through hole is revealed. Follow the proper connection instructions for your system with regard to which terminals are used. Once the connections are made, twist the cap back so that the connection is secured, but do not over tighten or use tools, as this may break the delicate wire strands and decrease system performance.

If you are using spade lugs, connect them to the speaker wire using the manufacturer’s instructions, and then loosen the caps on the speaker terminals. Place lugs between the plastic cap and the back of the terminal. Be sure to observe proper polarity, using the appropriate speaker hook-up icons for your system’s configuration.

Using your fingers, tighten to obtain a positive contact.

When using banana plugs, connections may be made by simply inserting the jack affixed to your speaker wire into the hole provided on the rear of the colored screw caps on the binding posts. Before using banana type jacks, make certain that the plastic screw caps are firmly tightened down by turning them in a clockwise direction until they are snug against the chassis. This will insure that the maximum surface area of the plug is

Rev-11/21

in contact with the jack. Be certain to observe proper polarity.

Run the cables to the speaker locations. Do not coil any excess cable, as this may become an inductor that creates frequency response variations in your system. Finally, connect the wires to the speakers, again being certain to observe proper polarity. Remember to connect your negative, or black wire, to the matching terminal on the speaker. The positive, or red wire, should be connected to the matching terminal on the speaker.

NOTE: While most speaker manufacturers adhere to an industry convention of using red terminals for positive connections and black terminals for negative, some manufacturers may vary from this configuration. To assure proper phase connections, and optimal performance, consult the identification plate on your speaker terminals, or the speaker’s manual to verify polarity. If you do not know the polarity of your speaker, consult the speaker’s manufacturer for further information.

Power Control Connections

Your amplifier features a built-in remote turn-on system that will automatically switch the amplifier on when another device in the system is switched on.

Remote Turn-On Using Products

Equipped With a Low Voltage Trigger Jack

Press the front panel power switch on the amplifier so that it is in the ON position. Then, using an accessory cable with a 3.5mm mono mini-plug on each end, connect the trigger-output jack on the rear of the source device to the trigger input jack on the back panel of the amplifier. When these connections are made, the amplifier will automatically turn on and off with the triggering device. The trigger is compatible with a 3 - 24 VDC steady state signal.

Remote Turn-On

Using External AC to DC Power Converter

If your source device does not have a dedicated trigger jack, it is still possible to activate the unit for automatic turn on when a Switched Outlet is available on the rear of the source device. To control the amplifier in this fashion, you will need a small AC to DC power converter, capable of delivering a 3.3 to 24 volt DC signal.

The DC voltage should terminate in a standard 3.5mm type mini plug. This type of converter may be obtained as a Power Adapter from many electronics retailers.

When installing, press the Main Power Switch on the front panel of the amplifier in so that it is in the ON position. Plug the AC adapter into a switched outlet on the source device that will be activated when you wish to have the amplifier turn on. This may be the switched outlet at the rear of an AV receiver or other audio equipment. Connect the 3.5mm mini-plug from the

AT3300 Manual 7 adapter to the trigger-input jack on the back panel of the amplifier. The amplifier will now turn on and off automatically, based on the status of the controlling device.

AC Power Connections & Cords

The AT3300 amplifiers include 1 or 2 IEC60320 C20 power inlets, depending on channels count. We provide

1 or 2 power cords for the amplifiers, again depending on channels count. For 120VAC operation, the supplied power cords have a NEMA 5-15P wall plug on one end. For 240V operation, the supplied power cords have either a CEE 7/7 “Schuko” plug or a BS1363 plug. Use the included power cord(s) to connect the amplifier to the AC source.

Once all audio and system connections have been made, connect the supplied power cords to the amplifier first, and then connect it to an AC power source.

Please make certain that the amplifier is turned off and that the device connected to the remote trigger input is off when connecting the power cord and plugging it into an AC outlet.

When the power cord is plugged into the wall outlet, and the main power switch / circuit breaker is in the on position, the amplifier is in the standby mode and draws less than 1 watt from the wall outlet.

NOTE : We recommend a direct connection to the wall outlet. Placing a power conditioner in between the AC source and the amplifier may reduce the overall power available to the amplifier and reduce the output power to drive your loudspeakers.

NOTE: For the 5-8 channel amplifiers, we also recommend that each power cord be plugged into a separate circuit. Separate circuits typically are connected to different circuit breakers at the main service panel of the building or sub-panel for the room/suite/theater.

NOTE: It is not recommended that you connect other power amplifiers, or products with a high current draw, to the same AC power circuit as the amplifier. If this is unavoidable, the Ultra-Soft-Start circuitry of your amp will prevent excessively high inrush current.

WARNING: Under no circumstances should the

“Earth” connection on the plug be cut, bent or in any other way defeated as this may result in severe shock.

WARNING : Do not attempt changes to your household electrical circuits by yourself, instead hire a licensed qualified electrician.

WARNING: Do not plug the amplifier directly into the

“Switched Accessory” outlet of another device! These outlets are intended for use with low current draw products having a low current draw, such as tuners,

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CD players or cassette decks. These cannot handle the high current draw of a power amplifier. Using these outlets for a power amplifier is a significant safety hazard.

WARNING: Always turn off the amplifier and unplug the power cord before making any electrical connections.

Amplifier Operation

Before turning on the AT3300, ensure that all precautions and warnings have been carefully reviewed and adhered to. Damage to the amplifier caused by improper operation, wiring and/or ventilation will not be covered under warranty and ATI will not be liable for any consequential damage or loss.

After all connections have been made you are ready for operation. First, turn on the source components and processor in your system. It is always a good idea to turn on your amplifier LAST. This avoids the possibility of any turn on pops or transients from other equipment being amplified and sent to your speakers where they may cause damage. Always start with a low volume level on your controller or preamp to avoid damage to your speakers.

Manual On

Simply press the front panel power switch. The switch will dimly light up during the soft-start sequence. There will be a couple clicks from the chassis, this is normal.

These are relays activating to pass AC to the large power transformers. After the turn-on process is complete, the front panel switch will illuminate fully. During the soft-start sequence audio will pass through the amplifier modules, but full power will not be available. To turn the unit off, press the Power button again.

NOTE: We recommend not playing audio during the turn-on soft-start sequence.

Automatic On

Make certain that the connection to the controlling device is correct. Whenever the controlling device is turned on, the amplifier will automatically turn on. You may also hear a relay click as during start up. This is also normal.

To turn off your amplifier, simply turn off the device feeding the amplifier it’s trigger signal. The amplifier will automatically go into a standby mode in a few moments.

ATI Service Information

The AT3300 series does not contain any user serviceable parts inside. If you suspect a problem that may require service assistance, contact us at support@ati-

AT3300 Manual 8 amp.com, or by phone at 323-278-0001. It is important that only an authorized service agent carry out any repairs. This will assure proper service and preserve the protection of your Limited Warranty. Keep your sales slip or receipt in a safe place with this manual so that it will be available to verify the purchase date, should you experience a problem covered by out warranty.

Care and Maintenance

Cleaning

When the unit becomes dirty, wipe it with a clean, soft, dry cloth. If necessary, first wipe the surface with a soft cloth slightly dampened with a mild soapy water, then with a fresh cloth dampened with clean water. Wipe dry immediately with a dry cloth. Never use benzene, thinner, alcohol or any other volatile cleaning agent. Do not use abrasive cleaners, as they will damage the finished of the metal parts. Avoid spraying insecticide, waxes, polishing agents, or any aerosol product near the unit.

Since these amplifiers have fans to help keep things cool, every once in while the inside of the chassis and fans will need to be dusted and cleaned out. Power off the amplifier and disconnect all cables before removing the top cover. Remove the top cover and with a can of compressed air or even a small electronics / computer vacuum clean out the fans and the inside of the chassis.

A Few Words About Hum and Noise

Audible hum, or a discernable low frequency noise, is one of the most common problems in audio/video systems. This hum, which may be present even when the volume is at a low level, is usually caused by a problem known as “ground loops”. A ground loop occurs when there is a difference in ground voltages between two or more components that are connected electrically. This, in turn, creates multiple current paths and causes the low-level noise, or hum.

The growing sophistication and complexity of home audio/video systems, and the increased number of components used to create these systems has dramatically increased the potential for the possibility of ground loops. While it is natural to suspect that the components in your system are the cause of the hum, in many cases the cause may be due to other conditions. In particular, cable TV connections from outside the house have become a major source of hum.

In most cases, one of the following suggestions should help you to solve a hum problem in your system. Please try these steps in the sequence shown, proceeding from one step to the next if the prior suggestion does not eliminate the problem.

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Potential Ground Loops in a Complex A/V System

Suggestion #1:

To determine if a cable TV connection is responsible for the hum, first turn all components off. Disconnect the cable TV feed to your system at the first place where it connects to your components. Alternatively, disconnect the cable TV wire where it is connected at the wall outlet. Turn your system back on, and listen if the hum has disappeared. If removing the cable TV feed has eliminated the hum, you will need to insert a

Ground Loop Isolator before reconnecting the cable TV feed, or contact your cable TV operator to see if they can better isolate your cable feed.

Suggestion #2:

Turn off all components in your system, and then disconnect the input cables at the amplifier. Turn the amplifier back on, and see if the hum is still present. If the hum disappears, the fault may be in the input cables used. Try replacing them with cables that have better shielding, and make certain that the input cables are not running on top of any AC power cords. Change the cables one at a time to determine if one, or all cables is responsive. If the hum disappears when the input cables are disconnected, but returns after the cables are changed and the system re-connected, the problem may be caused by your source device.

Suggestion #3:

Ground loop problems may also be caused by poor grounding of the electrical system in your home, particularly when there are multiple components with three prong, grounded, power cords. Try unplugging these components one at a time, and see if one or all of them is causing the problem. The ultimate solution to this type of problem is to re-wire your house with an isolated, star type-grounding configuration. We recognize, however, that this may be impractical and expensive. In some cases, the use of an approved AC Power Isolation

Transformer of sufficient capacity may solve this problem.

WARNING: If you suspect that the grounding system in your home’s electrical wiring is causing the hum problem, it is important that you do not make any changes to the wiring yourself. Only a licensed electrician should make any changes to household wiring, and they must be made in full compliance with all local building, safety and electrical codes.

Suggestion #4:

Hum may also be caused by faulty earth grounds in your home’s electrical system. In the past, cold water

AT3300 Manual 9 pipes were often used for the earth ground, so it is important to make sure that your ground connection is still valid and has not become loose or corroded. The cold water pipe method may no longer be valid in some locations due to requirements that the water meter be isolated from the water mains with a length of PVC pipe, thus interrupting the ground circuit. The safest, and most reliable, approach may be to provide your own ground. This can be accomplished by having a licensed electrician drive at least five feet of copperjacketed steel grounding rod into the earth, and using that for your grounding connection. If the hum persists after all of the above suggestions have been tried, contact the ATI customer service department for assistance.

Errors and Omissions Statement

ATI is not responsible for errors and omissions.

All product specifications are subject to change without notice.

Listed specifications and features are valid on the day of publication of this manual.

All trademarks are the properties of their respective owners.

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Appendix A - Troubleshooting Guide

Your ATI amplifier is designed for trouble free operation. If you follow the instructions in this manual you should enjoy many years of high quality listening enjoyment. However, as with any sophisticated electronic device, there may be occasional problems upon initial installation, or during the life of the unit. The items on the list below are a brief guide to the minor problems that you may be able to correct yourself. Please be sure to thoroughly check all other connected components such as speakers and preamplifiers, as well as cables. If the problem persists, please consult your installer, dealer, distributor or us for assistance.

Problem

No power or front panel lights

Possible Cause(s) Solution

The power cable is not inserted

100% into the AC input connector.

Ensure that the AC cord is fully inserted into the amplifier and that the wall outlet is active.

No power or front panel lights Circuit breaker is open (AC wall outlet)

Check the AC outlet circuit breaker and reset, if necessary, or contact your dealer.

No power or front panel lights Chassis breaker is open (Amplifier power switch)

Check the rear panel circuit breaker and make sure it is in the on position. If the circuit breaker does not stay in the on position, contact ATI for support.

Amplifier will not turn on or off when a trigger cable is connected.

Improper wiring of remote trigger Check voltage , polarity and connection of trigger wire.

Check all input connections. Amplifier turns on, but there is no audio from one or more channels.

Input cables are not connected to proper jack or are loose.

Amplifier turns on, but there is no audio from one or more channels.

Input select switches are in the wrong position.

Amplifier turns on, but there is no audio from one or more channels.

Audio levels differ.

No audio output

Speakers are not connected properly.

Improper settings or output levels from processor or controller.

Overheating, DC at output, Catastrophic failure

Check all input select switches and make sure they are in the correct position for the connection type,

XLR or RCA

Check speaker connections at the amplifier and speaker.

Check the settings on the preamp, processor or controller.

The amplifier will turn off. For any but a catastrophic failure, the amplifier can be reset by removing the fault and completing the turn-on sequence again.

Appendix B - Model Circuit Breaker Ratings

All models use medium time delay hydraulic-magnetic circuit breakers. Please contact ATI customer service if you need more information.

Model AT3308 AT3307 AT3306 AT3305 AT3304 AT3303 AT3302

Current Rating (120VAC) 2 X 20A 2 X 20A 2 X 15A 2 X 15A 20A 15A 12A

Current Rating (240VAC) 2 X 10A 2 X 10A 2 X 8A 2 X 8A 10A 8A

6A

AT3300 Manual 10 Rev-11/21

Appendix C - Specifications

- (Specifications subject to change without notice)

Analog Audio Inputs

Input Impedance

Input Sensitivity

Gain

Polarity

Speaker Output

Mode / Process

Power Output - 8 ohms

Per Channel

20 Hz-20 kHz, < 0.03% THD

1 kHz, 0.005% THD, (Watts)

Power Output - 4 ohms

Per Channel

20 Hz-20 kHz, < 0.075% THD

1 kHz, 0.015% THD, (Watts)

Distortion - 8 ohms

THD + N, 20 Hz - 20 kHz

THD + N @ 1 kHz, 1W

Intermodulation Distortion

(SMPTE or Twin-tone)

Frequency Response

Damping Factor - 8Ω load

Signal to Noise Ratio

Slew Rate

One Single-ended (RCA) jack per channel & One Balanced (XLR) jack per channel

Slide Switch to choose jack

20kΩ per leg - Nominal

2.01 Volts for rated power Into 8 ohms

28.2 dB ± 0.25

Unbalanced (RCA); Center Positive for Non-Inverting Output

Balanced (XLR); Pin-2 = Positive, Pin-3 = Negative for Non-Inverting Output

5-way Touch Proof Binding posts; 1 pair per channel

Standby: Amplifier is ready to be turned on via front panel switch or remote trigger.

Overcurrent, DC Offset, or Oscillation Protections: Amplifier will cycle. PROTECT LED will illuminate RED.

Catastrophic DC Offset, Output Stage Failure or Thermal: Amplifier will shut down.

330W

330W

425W

425W

< 0.05%

< 0.007%

Less than 0.03%

Crosstalk

Trigger Input

Dimensions (W x H x D)

AT3305 to AT3308

AT3302 to AT3304

Weight (lbs. / kg)

+0, -.5 dB, 5 Hz to 20 kHz, load independent

> 400 from 10Hz to 400Hz

> 125dB (A-Weighted - Ref. 8Ω FTC Power)

> 50V / µS

Adjacent Channels - Better than -80dB from 200Hz - 10kHz

Skipped Channels - Better than -90dB from 200Hz - 10kHz

Bank to Bank Channels - Better than -100dB from 200Hz - 10kHz

3.3-24 VDC; Steady State Tip Positive

17” x 9 3/4” x 17 5/8” (432 mm x 248 mm x 448 mm)

17” x 9 3/4” x 14 5/8” (432 mm x 248 mm x 372 mm)

AT3308: Amp - 101 / 45.9 , Shipping - XXX / XX.X

AT3307: Amp - 94.0 / 42.7 , Shipping - XXX / XX.X

AT3306: Amp - 87.0 / 39.6 , Shipping - XXX / XX.X

AT3305: Amp - 80.6 / 36.7 , Shipping - XX.X / XX.X

AT3304: Amp - 61.0 / 27.7 , Shipping - XX.X / XX.X

AT3303: Amp - 54.0 / 24.5 , Shipping - XX.X / XX.X

AT3302: Amp - 47.6 / 26.7 , Shipping - XX.X / XX.X

AT3300 Manual 11 Rev-11/21

Appendix D - Power Requirements & Consumption

1

Power Requirements

Power Consumption

117V/120V AC or 230V/240V AC; 50/60 Hz

Factory Configured

Less than 0.5W at Standby; 2X 2400W maximum

Standby

Idle 2

- Mains 1 AC Input

Idle 2

- Mains 2 AC Input

@ Rated Power (8Ω)

All Channels unless noted

Mains 1 AC Input

@ Rated Power (8Ω)

All Channels unless noted

Mains 2 AC Input

AT3302 AT3303 AT3304 AT3305 AT3306 AT3307 AT3308

50W

NA

70W

NA

90W

NA

<0.5 Watts

70W

50W

70W

70W

70W

90W

90W

90W

13.2A

3

1525VA

1240W

19.2A

3

2170VA

1780W

12.2A

3,5

2725VA

2250W

19.2A

3

2170VA

1780W

19.2A

3

2170VA

1780W

19.2A

3

2170VA

1780W

12.2A

3,5

2725VA

2250W

NA NA NA

13.2A

3

1525VA

1240W

19.2A

3

2170VA

1780W

12.2A

3,5

2725VA

2250W

12.2A

3,5

2725VA

2250W

Appendix E - Thermal Dissipation

1,6,7

Duty Cycle

Idle

10% (Continuous Speech)

20% (Background Music)

30% (Rock ‘N’ Roll)

40% (Compressed Rock Music)

50% (Pink Noise)

AT3302 AT3303 AT3304 AT3305 AT3306 AT3307 AT3308

175 240 310 415 480 550 620

370

570

510

780

630

950

880

1350

1020

1560

1140

1730

1260

1900

770

970

1170

1050

1320

1590

1275

1580

1900

1820

2290

2760

2100

2640

3180

2325

2900

3490

2550

3160

3800

1 - All measurements taken at the 120VAC line voltage, unless noted. For 240VAC line voltage, current draw will be ~0.5X the currents listed in the table. Measurements taken while driving amplifier channels with 1kHz sine wave into 8Ω resistive loads. Loading the amplifiers with 4Ω loads will double the current draw shown in the table.

2 - Nominal reading, ±5W.

3 - We do not recommend running the amplifiers for extended periods of time over the circuit breaker rating. This was done for testing purposes only.

4 - All channels driven at 330W per channel

5 - Amplifier configured for 240VAC line voltage. Power measurements taken at 240VAC line voltage. Current draw for

120VAC configurations will be ~2X the currents listed in the table.

6 - Thermal Dissipation is in BTU/hr.

7 - For model AT3305, AT3306, AT3307 & AT3308, the table shows the sum total thermal dissipation of both amplifier banks.

AT3300 Manual 12 Rev-11/21

Appendix F - AT3300 Family Rear Panel Views

AT3300 Manual 13 Rev-11/21

90-Day Limited Warranty

Terms and Conditions

(7-Year Optional Extended Warranty)

This ATI product is warranted against defects in materials and workmanship for a period of 90 days from the date of purchase by the original owner. The date of purchase shall be established by the original owner presenting to the ATI Customer

Service Facility the original owner’s purchase receipt or sales slip showing from whom the product was purchased, the date of purchase and the unit’s purchase price.

In the event that proof of purchase cannot be established as stated in the preceding paragraph, the warranty period shall commence on the date of manufacture, provided the serial number on the unit has not been altered in any manner.

During the warranty period, ATI will repair, or at its sole option, replace at no charge, components that prove to be defective provided the product is returned in accordance with the shipping instructions that are contained in the unit. The unit is to be sent FREIGHT PREPAID in the original carton and packing along with a detailed description of the problem to

ATI in the event it needs factory servicing. ATI will return the unit prepaid to you upon completion of the service

Optional Extended Warranty Program

The standard 90-Day Limited Warranty will be extended to a

7-Year Limited Warranty if the following conditions are met:

The ATI product is purchased from an authorized ATI reseller;

The customer completes and returns the registration card to

ATI or the ATI distributor (if the unit is purchased outside the

United States) or completes the warranty registration process at: www.ati-amp.com AND submits a copy of the original bill of sale to ATI within 14 days of purchase.

This extended warranty is transferrable to subsequent owners of the ATI component as long as all of the Optional Extended

Warranty conditions are met.

PLEASE RETAIN A COPY OF THE ORIGINAL PROOF

-OF-PURCHASE

. It will be necessary should in-warranty service ever be required.

Transferability

The above warranties are transferable to subsequent owners as long as all of the conditions are met under the Optional Extended Warranty Program. The warranty is not transferable if the unit was originally purchased from an unauthorized seller.

The above warranties do not apply if the product has been damaged by accident or misuse or as a result of modification by other than the ATI factory service facility.

ATI shall not be held liable for incidental or consequential damages of any kind arising from the sale or use of its products.

Some sates do not allow the exclusion or limitation of incidental or consequential damages, so the above limitation or exclusion may not apply to you.

THERE ARE NO WARRANTIES GIVEN BY ATI THAT EX-

TEND BEYOND THE DESCRIPTION ON THE FACE HERE-

OF. ALL IMPLIED WARRANTIES OF FITNESS FOR PUR-

POSE SOLD, MERCHANTABILITY, DESCRIPTION,

QUALITY PRODUCTIVENESS OR ANY OTHER MATTER

ARE LIMITED TO THE TERM OF THE EXPRESS WAR-

RANTIES HEREIN STATED.

Some states do not allow limitations on how long an implied warranty may last, so the above limitations may not apply to you.

Obligation to Make Changes

Products are sold on the basis of specifications applicable at the time of sale. ATI shall have no obligation to modify or to update products once sold.

This warranty gives you specific rights and you may also have other rights that vary from state to state. This warranty is applicable only in the United States.

Warranty Outside the United States

ATI has formal distribution agreements in many countries. The

ATI importer in those countries has assumed the responsibility for servicing ATI products. Please contact the dealer or distributor in the country where you purchased your product for any service issues.

Amplifier Technologies, Inc.

1749 Chapin Road

Montebello, CA 90640 USA

Tel: (323) 278-0001 Fax: (323) 278-0083 www.ati-amp.com [email protected]

AT3300 Manual Rev-11/21