background image
KAC-728
KAC-628
KAC-528
POWER AMPLIFIER
INSTRUCTION MANUAL
B64-1360-00 (EM)


background image
To prevent injury and/or fire, take the
following precautions:
· When extending the battery or ground
cables, make sure to use automotive-grade
cables or other cables with an area of 5 mm2
(AWG10) or more to prevent cable
deterioration and damage to the cable
coating.
· To prevent short circuits, never put or leave
any metallic objects (e.g., coins or metal
tools) inside the unit.
· If the unit starts to emit smoke or strange
smells, turn off the power immediately and
consult your Kenwood dealer.
· Do not touch the unit during use because the
surface of the unit becomes hot and may
cause burns if touched.
To prevent damage to the machine, take the
following precautions:
· Be sure the unit is connected to a 12V DC
power supply with a negative ground
connection.
· Do not open the top or bottom covers of the
unit.
· Do not install the unit in a spot exposed to
direct sunlight or excessive heat or humidity.
Also avoid places with too much dust or the
possibility of water splashing.
· When replacing a fuse, only use a new one
with the prescribed rating. Using a fuse with
the wrong rating may cause your unit to
malfunction.
· To prevent short circuits when replacing a
fuse, first disconnect the wiring harness.
· If you experience problems during
installation, consult your Kenwood dealer.
· If the unit does not seem to be working right,
consult your Kenwood dealer.
Cleaning the unit
If the front panel gets dirty, turn off the power
and wipe the panel with a dry silicon cloth or
soft cloth.
Do not wipe the panel with a hard cloth or a
cloth dampened by volatile solvents such as
paint thinner and alcohol. They can scratch the
surface of the panel and/or cause the indicator
letters to peel off.
Accessories
2CAUTION
NOTE
2CAUTION
2WARNING
2
Safety precautions
Part name
Number of
Items
External
View
Round terminal
(Large)
1
Round terminal
(Medium)
2
Round terminal
(Small)
1
Terminal cover
(Power terminal)
1
Self-tapping screws
(ø4
× 16 mm)
4


background image
3
Protection function
This unit is equipped with a protection function for protecting this unit and your speakers
from various accidents or problems that can occur.
When the protection function is triggered, the Power indicator goes off and the amplifier
stops operating.
s Power indicator:
When the power is turned on, the Power indicator lights.
If the Power indicator does not light when the power is turned on, the
protection function may be activated. Check whether there is any
indication of trouble.
s The protection function activates in the following
situations:
· When a speaker cable may be short-circuited.
· When a speaker output contacts ground.
· When the unit malfunctions and a DC signal is sent to the speaker
output.
· When the temperature of internal parts exceeds 120°C (248°F).
· When a ground cable of the center unit (cassette receiver, CD receiver,
etc.) or this unit is not connected to a metal part serving as an
electrical ground passing electricity to the battery's negative -
terminal.
Power indicator
Installation procedure
1. Remove the ignition key and disconnect the negative - terminal of the battery to prevent short
circuits.
2. Set the unit according to the intended usage.
3. Connect the input and output cables of the units.
4. Connect the speaker cables.
5. Connect the power cable, power control cable and grounding cable following this order.
6. Install the unit in the car.
7. Connect the negative - terminal of the battery.
· Be sure to turn the power off before changing the setting of any switch.
· If the fuse blows, check cables for shorts, then replace the fuse with one of the same rating.
· Check that no unconnected cables or connectors are touching the car body. Do not remove
caps from unconnected cables or connectors to prevent short circuits.
· Connect the speaker cables to appropriate speaker connectors separately. Sharing the negative
cable of the speaker or grounding speaker cables to the metal body of the car can cause this
unit to fail.
· After installation, check that the brake lamps, winkers, and wipers work properly.
2CAUTION


background image
4
Controls
Operations of the following control and switches are required in accordance with the center
unit and speakers connected with this unit.
FUSE(15A)
POWER IN
BATT
P.CON(REMOTE)
GND
LEFT
BRIDGED
RIGHT
SPEAKER OUTPUT
POWER AMPLIFIER
15
LPF
FILTER
OFF
MONO(Lch)
STEREO
OPERATION
GND
INPUT
SENSITIVITY(V)
MAX
MIN
0.3
0.5
1.0
L
R
LINE IN
LEFT
RIGHT
SPEAKER LEVEL INPUT
FUSE(25A)
POWER IN
BATT
P.CON(REMOTE)
GND
LEFT
BRIDGED
RIGHT
SPEAKER OUTPUT
POWER AMPLIFIER
25
LPF
FILTER
HPF
MONO(Lch)
STEREO
OFF
L+R
OPERATION
GND
INPUT
SENSITIVITY(V)
MAX
MIN
0.3
0.5
1.0
L
R
LINE IN
LEFT
RIGHT
SPEAKER LEVEL INPUT
LPF
FILTER
OFF
MONO(Lch)
STEREO
OPERATION
GND
INPUT
SENSITIVITY(V)
MAX
MIN
0.3
0.5
1.0
L
R
LINE IN
LEFT
RIGHT
SPEAKER LEVEL INPUT
FUSE(20A x 2)
POWER IN
BATT
P.CON(REMOTE)
GND
LEFT
BRIDGED
RIGHT
SPEAKER OUTPUT
POWER AMPLIFIER
20
20
1
!
0
9
8
7
!
0
9
8
7
!
6
0
9
8
7
5
4
3
2
1
6
5
4
3
2
1
6
5
4
3
2
KAC-628
KAC-528
KAC-728
KAC-628
KAC-528
KAC-728


background image
5
1
RCA cable ground lead terminal
2
FILTER switch
These switches allow filtering of the
speaker output signals.
· HPF (High Pass Filter) position
(KAC-628 only)
Only frequencies of 150 Hz or higher are
output. (Frequencies below 150 Hz are cut.)
· LPF (Low Pass Filter) position
Only frequencies of 80 Hz or lower are
output. (Frequencies above 80 Hz are cut.)
The Lch and Rch will be mixed before
output even if the operation switch is set to
STEREO.
· OFF position
The original sound without filtering is
output.
3
OPERATION switch
This switch allows selection of the
amplification method of input signals.
· STEREO position
The amplifier can be used as a stereo
amplifier.
· L+R position (KAC-628 only)
The input left and right signals are
combined before being amplified. Use this
position when the unit is used for
subwoofer speakers or the L+R (monaural)
sound is required.
· MONO (Lch) position
Amplifies the signal input from the left side
only. Set to this position and make bridged
connections to use as a high-power
monaural amplifier. (The input right signal is
not output.)
4
INPUT SENSITIVITY control
Set this control according to the pre-output
level of the center unit connected with this
unit, or to the maximum power output of
the genuine-accessory car stereo.
Use the diagram on the
right as a guide.
For the pre-output level or
the maximum power output,
refer to the "Specifications"
in the instruction manual of the center unit.
5
LINE IN terminal
6
Speaker level input terminals
7
Fuse (20 A
× 2 : KAC-728)
Fuse (25 A
× 1 : KAC-628)
Fuse (15 A
× 1 : KAC-528)
8
Battery terminal
9
Ground terminal
0
Power control (REMOTE) terminal
!
SPEAKER OUTPUT terminals
· Stereo Connections:
When you wish to use the unit as a stereo
amplifier, stereo connections are used.
The speakers to be connected should have
an impedance of 2
or greater. When
multiple speakers are to be connected,
ensure that the combined impedance is 2
or greater for each channel.
· Bridged Connections:
When you wish to use the unit as a high-
output monaural amplifier, bridged
connections are used. (Make connections
to the LEFT channel (+) and the RIGHT
channel (­) SPEAKER OUTPUT terminals.)
The speakers to be connected should have
an impedance of 4
or greater. When
multiple speakers are to be connected,
ensure that the combined impedance is 4
or greater.
The rated input of the speakers should be
no less than the maximum output of the
amplifier. Otherwise malfunction may
result.
2CAUTION
NOTE
MAX
MIN
0.3
0.5
1.0
(W)
25
15
10
LPF
FILTER
OFF
KAC-728/528
LPF
FILTER
HPF
OFF
KAC-628
MONO(Lch)
STEREO
OPERATION
KAC-728/528
MONO(Lch)
STEREO
L+R
OPERATION
KAC-628