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VIBE MonoBox III Class AB Analogue Amplifier
PRODUCT DESCRIPTION
The VIBE MonoBox III amplifier provides 1×400 watts of power into a 4 Ohm Load and 1×600 watts of power
into a 2 Ohm load. This full featured model is an excellent choice for a variety of car audio subwoofer system
configurations.
The MonoBox III uses an unregulated MOSFET power supply for superior control of output wattage. A toroid-coil
transformer yields maximum power transfer with minimum heat loss. Careful attention to circuit design keeps AM
RFI at low levels, so you won't hear unwanted noise when the level is cranked up. Protection circuits safeguard
the amplifier when overheating and speaker shorts or improper load conditions occur.
All connections and controls for the MonoBox III are on the end panels and are easy to understand. We use gold-
plated RCA and barrier connectors to ensure the best electrical connection for your system. Included are external
automotive type fuses that are easy to replace.
INPUT CONNECTIONS AND AUDIO CONTROLS
The front panel of the MonoBox contains connections for RCA Inputs, Remote level control and Audio Controls as
shown on the figures below. The RCA Input Connections are gold-plated RCA jacks and are labelled as RIGHT and
LEFT .
Figure 1: MonoBox III Front Panel
1.
Subsonic Filter
6. Bass Enhance Level Control
2.
Remote Level Port
7. Gain Control
3.
Low Pass Filter Control
8. High Level Input Socket
4.
Filter Selector
9. RCA Input Jacks
5.
Bass Enhance Frequency Control
10. RCA Output Jacks
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VIBE MonoBox III Class AB Analogue Amplifier
TROUBLESHOOTING
Problem:
No Audio
Solution:
§
Low or no remote turn-on voltage – check remote connections at amplifier and source unit
§
Blown amplifier fuse – replace with new fast-blow fuse (same rating)
§
Power wires not connected – check battery and ground wiring at amplifier, and also check battery
connections
§
Speaker leads shorted – check speaker continuity to ground – it should not show a common ground
§
Speakers not connected or are blown – check speaker connections at amplifier, measure coil impedance
Problem:
Audio cycles on and off
Solution:
§
Thermal protection circuits are shutting the amplifier off – check location for adequate ventilation; consult an
authorised VIBE Audio Dealer
Problem:
Distorted Audio
Solution:
§
Gain is not set properly, or damaged speaker cones – review setting gain; inspect each speaker cone for signs
of damage (i.e. frozen cone, burning smell etc.)
Problem:
Audio lacks punch
Solution:
§
Speakers wired incorrectly, causing cancellation of bass frequencies – check polarity of wires from amplifier
to each speaker as defined by the system design
Problem:
Amplifier fuse keeps blowing
Solution:
§
Incorrect wiring or short circuit – review installation and check all wiring connections
Problem:
Whining or ticking noise in the audio with engine on
Solution:
§
Amplifier is picking up alternator noise or radiated noise. Turn down input gain; move audio cables away from
power wires. Check power and ground connections on amplifier – install an in-line noise filter on source
unit’s power wire. Check alternator and/or voltage regulator – test for weak battery or add water to battery
