Bedienungsanleitung JL Audio MHD900 (Seite 8 von 13) (Englisch)

700488

Zoom out

Zoom in

Vorherige Seite

1/13

Nächste Seite

14 | JL Audio - MHD900/5 Owner’s Manual

“STATUS” LED / PROTECTION CIRCUITRY

There is a single multi-color LED on the

control panel of the amplifier to indicate the

amplifier’s operating status. This LED’s behavior

is as follows:

1) Flashing Green: amplifier is powering up,

audio output is muted.

2) Constant Green: amplifier is on and

functioning normally, audio output is active.

3) Constant Red: lights to indicate that the

amplifier has exceeded its safe operating

temperature, putting the amplifier into a self-

protection mode, which temporarily reduces

the peak power output of the amplifier. The

red light will turn green and the amplifier will

return to full-power operating mode when its

temperature returns to a safe level.

3) Constant Amber (yellow): lights to indicate

that at least one channel is in overcurrent

protection mode. This could mean that the

impedance of the speaker load connected to

the amplifier is lower than the optimum load

impedance range for the amplifier. When this

light is on, a protection circuit engages and

reduces the power output of the channel(s)

experiencing the problem. This can manifest

itself as audible distortion.

The amber indicator will also light when

a short-circuit is detected in the speaker

wiring (this can be a short between the

positive and negative speaker wires or

between either speaker wire and the vessel

chassis). This can be used to diagnose a

short-circuit by only connecting one of the

amplifier sections at a time (“Front” or

“Rear” or “Sub” channels). The amber LED

will light when you connect the section that

is experiencing the problem and turn the

volume up. Note that a short in the speaker

wiring may show an alternating red/green

status light with no signal (volume down).

4) Alternating Red and Green: lights to indicate

that the amplifier is experiencing a fault that

may require service of the amplifier, its wiring

or the vessel’s charging system. Audio is muted

when this fault occurs. The most likely cause

of this fault is a low supply voltage condition.

If battery voltage drops below 8.5 volts at any

point, the amplifier (except for the “Status”

LED) will shut itself off to protect itself and the

vessel’s charging system. If the Remote Turn-

On voltage drops below 6 volts, the “Status”

LED will also turn off.

The amplifier will turn back on automatically

when voltage climbs back above 9 volts. This

shut-down and turn-on behavior may happen

in a rapid cycle when bass-heavy program

material causes a weak charging system to

momentarily dip too low. If this is happening

in your system, have your charging system

inspected to make sure it is working properly.

If no problem is found with the supply voltage

to the amplifier and you are still seeing

alternating Red and Green on the “Status”

LED, check that there are no short-circuits to

chassis ground in any of the speaker wiring

in the vessel. Disconnect speaker connectors

from the amplifier one-by-one to check.

If no problem is found with the supply or

remote voltage, disconnect everything except

power/ground/remote. If the amplifier is then

turned on and displays an alternating red-

green, the amplifier needs service.

For more information on troubleshooting this

amplifier, refer to Appendix D (pages 20, 21).

BRIDGING CONSIDERATIONS

Bridging is the practice of combining the output

of two amplifier channels to drive a single load.

When bridged, each channel produces signals

of equal magnitude, but opposite polarity. The

combined output of the two channels provides

twice the output voltage available from a single

channel. The MHD900/5 has been designed for

bridging of its two main channel pairs without the

need for input inversion adaptors.

The mono subwoofer channel cannot be

bridged to another mono channel.

To bridge either pair of main channels, use the

“Left +” and “Right –” speaker connectors only

(the “Left –” and “Right +” remain unused).

Then connect a mono signal to both left

and right RCA inputs for that channel pair.

This requires an RCA “Y-Adaptor” (sold

separately), because a bridged pair of channels

requires that both amplifier channels of the

bridged pair receive input. Connection of

only one RCA input will result in reduced

power output, increased distortion and

can cause the amplifier to overheat.

When bridged, each channel pair will

deliver optimum power into a 3-8Ω load.

Operating bridged channel pairs into a load

lower than 3Ω is not recommended.

Speaker Connector Plugs

There are three speaker connector

plugs on the MHD900/5: one for the

front channels, one for the rear channels

and one for the subwoofer channel.

To connect the speaker wires to the amplifier,

unplug the speaker connector plugs from the

amplifier chassis (pull back firmly) and back out

the set screws on each connector plug, using the

supplied 2.5 mm hex wrench. Strip 3/8 inch (10

mm) of insulation from the end of each wire and

insert the bare wire into the receptacle on the

speaker connector plug, seating it firmly so that

no bare wire is exposed. While holding each wire

in place, tighten each set screw firmly, taking care

not to strip the head of the screw.

Speaker loads below 1.5Ω nominal per channel

in stereo or 3Ω nominal in bridged mode are

not recommended and may cause the amplifier

output to distort excessively.

JL Audio MHD900 Seite 8

Brauchen Sie Hilfe? Stellen Sie Ihre Frage.

Missbrauch melden von Frage und/oder Antwort

Art des Missbrauchs:

Forenregeln

Neu registrieren

Andere Handbücher von JL Audio MHD900

Das Handbuch wird per E-Mail gesendet. Überprüfen Sie ihre E-Mail.

Ihre Frage wurde zu diesem Forum hinzugefügt

Info