Kenwood KAC-PS500F instruction manual Power indicator, Sigma servo feed back, Combined Impedance

Power indicator

■ Power indicator:	Power indicator
This lamp indicates the status of the unit,
including the power supply and protection
function, by lighting in red, amber or green or
turning off.
When power is turned ON, it lights in green
for a few seconds, then turns red when
normal operation starts.

■The protection function is activated in the following situations:

This unit incorporates a protection function which protects the main unit and speakers from troubles. The unit stops to function when the protection function is activated.

• If the POWER INDICATOR lights in green:

• A speaker cable may be short-circuited.

• A speaker output may be in contact with the ground.

• The temperature of the internal parts may be higher than 120°C (248°F)

• The sigma servo connection may be erroneous.

• The fuse of this unit may be blown.

• The unit may be malfunctioning and sending DC signal to the speaker output.

• If the POWER INDICATOR does not light up:

• The grounding cable of this unit may not be connected with a metallic part which is

electrically connected with the negative terminal of the battery.

• The power control cable may not be connected to this unit.

Sigma servo feed back

The sound reproduced through conventional amplifiers is distorted due to the counterelectromotive force produced in the oscillating system of the speaker. The counterelectromotive force is particularly high with the woofer which requires a large drive mass.The sigma servo connection reduces distortion caused by the counterelectromotive force by including the circuit up to the speaker terminals in the negative feedback loop. This makes it possible to drive speakers with more fidelity to the input signals and create a sharp bass sound image with few feeling of noise interference.

The aforementioned effects will not be obtained when the sigma servo connection has not been made.

NOTE

The speaker cable and the sigma servo cable should be wired to run along the same route. Note that this wiring should be separated from the power supply cable.

2CAUTION

•The SIGMA SERVO FEEDBACK terminals should be connected properly. Failure to connect them properly will be the cause of breakdown.

•The rated input of the speakers connected to this unit should be no less than the maximum output of the amplifier. Otherwise malfunction may result.

Be specially careful in this when connecting speakers in a parallel configuration.

•Speakers that are to be used for bridged connections to this unit should have an impedance of 4Ω or greater. When connecting multiple speakers, ensure that the combined impedance is 4Ω or greater. Connection of speakers of less than 4Ω will be the cause of breakdown.

• The grounding cable of the center unit (cassette receiver, CD receiver, etc.) may not be

connected with a metallic part which is electrically connected with the negative terminal of

the battery.

• The fuse of this unit may be blown.

■ Drop in supply voltage (If the POWER INDICATOR lights or blinks in

amber):

When the power supply voltage drops below 11.5 V, the POWER INDICATOR lights in amber.

If the POWER INDICATOR blinks or lights in amber, check the following items and make sure

to supply enough power to this unit.

• Is the battery cable too thin to supply enough power?

■Basic sigma servo connection

L

BRIDGED

R

ΣSERVO Ι FEED BACK

■Series connection

L

BRIDGED

R

Σ SERVO Ι FEED BACK

2CAUTION

Make this cable as short as possible.

• Is the battery cable deteriorated?

• Is the battery exhausted?

■ Parallel connection (1) ■ Parallel connection (2)

2CAUTION

Do not use thin or deteriorated cables for this may cause heat generation or burn. The cable used should be thick enough (5 mm2 or more) to supply power.

Combined Impedance

Refer to the diagrams below and ensure that the combined impedance is 2Ω or greater for

L

BRIDGED

R

Σ SERVO Ι FEED BACK

2CAUTION

The speaker cables connected to this unit should be thick enough to supply the current capacity of two speakers.

L

BRIDGED

R

Σ SERVO Ι FEED BACK

2CAUTION

This connection is possible only when the speakers are identical and the speaker cables are also of the same type and length.

stereo connections and 4Ω or greater for bridged connections.

■ Basic connection	■ Series connection	■ Parallel connection
4 Ω	4 Ω
4 Ω	4 Ω		4 Ω	4 Ω
	8 Ω	2	Ω

■Stereo Connections When the Aforementioned Connections Are Not Possible

L		L
BRIDGED
	L	BRIDGED
R	BRIDGED	R
Σ SERVO Ι	R	Σ SERVO Ι
FEED BACK
		FEED BACK
	Σ SERVO Ι
	FEED BACK

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