PowerBass ATM 330.2, ATM 440.2, ATM 550.4, ATM 660.4, Autosound ATM 330.2 Owner's Manual

ATM COMPACT CLASS A/B AMPLIFIER

Owners Manual

Please read through this manual to familiarize yourself with your new amplifier. Should your PowerBass

AutoSound mobile amplifier ever require service, you will need to have the original dated receipt.

ATM 330.2
ATM 440.2
ATM 550.4
ATM 660.4

Thank you and Congratulations

Thank you for your decision to purchase a PowerBass USA Autosound mobile amplifier! Our Autosound
amplifiers are the result of extensive engineering, testing, and bullet proof construction. Their versatility
enables compatibility with optional signal and audio processors. These high quality MOSFET amplifiers
may be configured to allow maximum flexibility in designing different types of speaker systems.

COMPACT A/B CLASS FULL RANGE AMPLIFIERS

The PowerBass Atom Series are high quality MOSFET amplifiers that are capable of running a system full
range, or they may be selected only to power subwoofers. It is important that you closely follow the wiring
instructions contained in this Owners Manual so that you get the most from your PowerBass AutoSound
mobile amplifier.

∆ Caution ∆
High powered audio systems in a vehicle are capable of generating higher then “Live Concert” levels of sound pressure. Continued
exposure to excessively high volume sound levels will cause hearing loss or damage. Also, operation of a motor vehicle while listening
to audio equipment at high volume levels may impair your ability to hear external sounds such as horns, warning signals, or emergency
vehicles—thus creating a potential traffic hazard. In the interest of safety, PowerBass USA highly recommends listening at lower volume
levels when driving.

TECHNICAL FEATURES

• Low Profile Aluminum Finned Heatsink

• High and Low Level Line Inputs

• Double Sided Circuit Board Construction

• PWM MOSFET Power Supplies for High Power Output and Best Stability into Low Impedance Loads

• Variable High Pass and Low Pass Electronic Crossover

• Soft Delay Remote Turn On/Off Circuit to Eliminating Pops and Clicks

• Selectable Bass EQ at 40Hz (0, 6 or 12dB)

• Self Diagnostic Multi Protection Circuit with LED Status Indicator for; Impedance Over-load, Speaker

Short Circuit, Thermal Overheating, and DC Output.

• 2-ohm Stereo Stable (4-ohm Mono Bridgeable)

• Custom Tooled Solderless Speaker and Power Terminal Blocks

• Variable Gain Control

• Fan cooled (ATM 550.4 and ATM 660.4 only)

INSTALLATION EXPERIENCE

Installation of PowerBass mobile amplifiers requires detailed knowledge of electronics wiring and proper
speaker impedance. We strongly recommend installation by an authorized PowerBass dealer. This Own­ers Manual only provides general installation and operation instructions. If you have any reservations
about your installation skills, please contact your local PowerBass dealer for assistance.

IMPORTANT : This amplifier is designed for operation in vehicles with 12-volt Negative ground
electrical systems only.

PREPARING FOR INSTALLATION

NOTE: The tools listed below may be required for basic installation

• An electric drill with bits

• Philips head and standard screwdrivers

• Wire strippers

• Crimping tool

• VOM (electronic volt ohm meter)

• Heat shrink tubing and heat gun

• Soldering iron

• Electronic (not Acid Core) Solder

3

INSTALLATION PRECAUTIONS

NOTE: Proceed only if you are a qualified installer, otherwise; see your Authorized PowerBass
Dealer to professionally install this amplifier. Always wear protective eyewear when using
tools.

• Turn off all stereo and other electrical devices before you begin.

• Disconnect the negative (-) lead from your vehicles battery.

• Locate all fuel lines, brake lines, oil lines, and electrical cables when planning the install.

• Make sure there is at least 2-inches (5 cm) around the air vents on the amplifier.

• When connecting ground points, make sure all paint is carefully scrapped away from the chassis

and contact is made with bare metal.

• Use a utility knife to trim away fabric from hole locations before drilling or cutting.

• When running power cables through sheet metal, be sure to use grommets to properly insulate the

metal edges from the wire insulation.

• If possible, use tubing through grommets.

To keep your PowerBass Atom amplifier running at top performance, choosing the proper location is of
utmost importance. For this reason the amplifier should be mounted in a location which will allow air to
circulate freely. A clearance of at least 2-inches (5 cm) to all sides of the amplifier is necessary not only
for proper cooling, but also for gaining access to the inputs and other variable controls. Be sure that the
power and signal cable connections can enter and leave the amplifier in a straight line to avoid the risk
of kinked wires causing malfunction.

Fig.1 Mounting Amplifier

MOUNTING THE AMPLIFIER

MOUNTING LOCATION

Find a clear and well ventilated area to mount your amplifier that is unobstructed by any objects that will cause
harm or block ventilation. You may use the amplifier as a template and mark the four screw locations with a
felt tip pen. Set the amplifier aside before drilling. Use caution to make sure there are no objects behind the
installation surface that may become damaged during drilling.

If mounting under a seat, make sure there is at least 1-inch (2.5 cm) of space above the amplifier’s heatsink
to permit proper cooling.

The amplifier should be protected from exposure to moisture and direct sunlight. The best places to mount
your amplifier are: The floor of the trunk, under a seat, or on the back of the rear seat. For alternate installation
locations, please consult your authorized PowerBass Dealer.

NOTE: Do not use a drill with driver bit to mount the amplifier. Excessive force could cause
the plastic mounting feet to crack.

*** WARNING ***

• Do not install in a place where it could injure the driver or passengers if the vehicle
stops suddenly.

• Upside down mounting will compromise heat dissipation through the heatsink and
could engage the thermal protection circuit.

• Try to avoid mounting the amplifier on a subwoofer enclosure, as extended exposure
to vibration may cause malfunction of the amplifier.

• Don’t mount the amplifier so that the wire connections are unprotected or are sub­ject to pinching or damage from nearby objects.

• The DC power wire must be fused at the battery positive (+) terminal connection.
Before making or breaking power connections at the amplifier power terminals,
disconnect the DC power wire at the battery end.

• The battery of the car audio system must be disconnected until the entire wiring and
installation is completed.

• Don’t use a power drill to tighten the power, ground, remote or speaker output
terminals on the amplifier to avoid stripping the terminal screws. It is best to hand
tighten these connections.

5

CONTROL PANEL LAYOUT

NOTE: Panel Layout and Controls may differ by model.

1. Line INPUT (RCA) Jacks
These RCA style input jacks are for use with source units that have RCA line level outputs. A source unit with a
minimum output of 200mV is required for proper operation. However, this input will accept levels up to 5Vrms.

2. GAIN Control

This control is used to match the input sensitivity of the amplifier to the particular source unit that you are
using.

3. HIGH INPUT

Allows you to connect speaker output from factory radio to amplifier without the use of a low level convertor.

4. BASS EQ Switch

This equalization circuit is used to enhance the low frequency response of the vehicle’s interior. Selectable for
6 or 12dB of boost centered at 40Hz, the BASS EQ can be adjusted to meet your own personal taste.

Fig.2 Panel Layout

5. LPF (Low Pass Filter) Control

This control is continuously adjustable from 50Hz through 500Hz at 12dB per octave.

6. X-OVER Switch for FULL/HPF/LPF

Activates the built in electronic crossover network. Works in conjunction with the HPF and LPF adjustable
controls.

7. HPF (High Pass Filter) Control

This control is continuously adjustable from 50Hz through 500Hz at 12dB per octave.

8. POWER/STATUS Indicator

The clear LED turns BLUE whne the power is on. Should the LED turn RED this is an indicator there is a problem
with the system in relation to the amplifer (see Troubleshooting Tips).

9. SPEAKER Output Terminals

As shown in the wiring diagrams, be sure to observe speaker polarity through the system and speaker imped­ance. This specially tooled solderless terminal is designed to accommodate up to 10 gauge speaker wire.

10. FUSE

For convenience most PowerBass AutoSound amplifiers utilize common automotive ATC type fuses. For con­tinued protection in the event that a fuse blows, replace the fuse only with the same value. (See speficification
tables)

11. BATT+ (Power Input Connection)

This terminal is the main power input for the amplifier and must be connected directly to the positive (+) ter­minal of the car battery. This specially tooled solderless terminal is designed to accommodate up to 4 gauge
power wire. (see Power Cable Selection Chart for recommended wire gauge for each model)

12. REM (Remote Input Connection)

All PowerBass AutoSound amplifiers can be turned on by applying 12 volts to this terminal. This can be found
on the rear of the source unit in the form of an electric antenna output, or a remote output. If this is not avail­able you can wire to the ACC position on the key. An 18 gauge wire is sufficient to run the REMOTE.

13. GND (Ground Input Connection)

A good quality ground is required for your PowerBass AutoSound amplifier to operate at peak performance.
A short length of cable the same gauge as your power cable should be used to attach the ground terminal
directly to the chassis of the vehicle. Make sure that all of the paint is sanded or scraped away to ensure a
quality ground connection.

7

*** WARNING ***

Disconnect the negative (-) battery terminal before you start any wiring work! The bat-

tery of your car audio system must be disconnected until the entire wiring installation is

completed.

Your PowerBass Autosound amplifier requires unrestricted current to deliver peak performance, so do not
“starve” your amplifier by using small power cable. Using under sized power cable can result in unnecessary
over-heating of the amplifier, distortion at high volume levels and might even cause the thermal protection
circuitry to shut-off the amplifier. For best results we recommend a PowerBass amplifier install kit, available
at your local PowerBass dealer.

• Use rubber grommets when running cables through any metal or sharp plastic, to prevent accidental
shorting or shearing. Make sure the cables do not interfere with normal operation of the vehicle.

• The audio signal cables (RCA interconnects) should be kept far away from any potential sources of
electrical interference such as electronic vehicle management systems (relays, engine computers etc.),
wiring harnesses, fuel pumps etc.

POWER WIRING AND SIGNAL CONNECTIONS

Fig.3 Power Input Connection