KAC-746
4-CHANNEL POWER AMPLIFIER
INSTRUCTION MANUAL
© B64-1176-00 (EM)
2
Safety precautions
Take the following precautions to
prevent fire and avoid personal
injury :
· When extending the battery cable, or
ground cable, use 5mm2 (AWG10) or
larger automotive grade cable to avoid
cable deterioration or damage to the
covering.
· Check that no metal objects (coins, tools,
etc.) are left inside the unit to avoid short
circuits.
· If you smell or see smoke, turn the
power off 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.
Take the following precautions to
keep the unit in proper working
order.
· Be sure the unit is connected to a 12V
DC power supply with a negative ground
connection.
· Do not open the top or bottom cover.
· Do not install the unit in places it is
exposed to direct sunlight, high heat or
humidity, water may splash over it, or
dust exists.
· If you have difficulty in installing this unit
in your vehicle, contact your Kenwood
dealer.
Cleaning the unit
· If the surface is dirty, wipe it clean with a
silicon cloth or soft dry cloth with the
power off.
Do not use hard cloths or paint thinner,
alcohol, or other volatile solvents. These
may damage external surfaces or remove
indicator characters.
2CAUTION
NOTE
2CAUTION
2WARNING
Accessories
Part name
Number
of Items
External
View
Battery cable
(Yellow) (6 m)
1
Ground cable (Black)
(1 m)
1
Self-tapping screws
(ø4
× 16 mm)
4
Terminal cover
(Power terminal)
1
Part name
Number
of Items
External
View
Round terminal
(Large)
1
Round terminal
(Medium)
2
Round terminal
(Small)
1
Grommets
1
3
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
Installation
· Since the power amplifier has no parts which require operation, it can be installed at a position
away from the driver's seat without any hindrances.
As generally accepted positions for its installation, places such as inside the trunk, etc. can be
considered.
· Use the extension cables. (Optional.)
· Do not install the unit under the carpet. Otherwise heat build-up occurs and the unit may be
damaged.
· Install this unit in a location which allows heat to easily dissipate.
Once installed, do not place any object on top of the unit.
· After installing the unit, check to make sure that electrical equipment such as the brake lamps,
turn signal lamps and windshield wipers operate normally.
· Install the unit securely in a location that does not interfere with driving.
2CAUTION
Installation board, etc.
(thickness : 15 mm or more)
Self-tapping screw
(ø4
× 16 mm)
CA-2SL
CA-12SL
CA-22SL
CA-52SL
RCA cable
CA-3WL
CA-13WL
CA-23WL
CA-53WL
RCA cable (ø7mm)
CA-5W
CA-15W
CA-25W
CA-45W
CA-65W
RCA cable (ø12mm)
0.5m
1m
2m
4m
5m
6m
Type
Length
4
Controls
This is a 4 channel amplifier including 2 stereo amplifiers in a body. One amplifier is
referred to as amplifier A and the other is amplifier B. This unit is compatible with
a large variety of systems by combining the switches and functions described in
the following.
LINE OUT
INPUT
SENSITIVITY(V)
CONTROL
FREQUENCY(Hz)
OPERATION
4 CHANNEL
POWER AMPLIFIER
L
R
B
LPF
OFF
FILTER
HPF
B
A
MONO(Lch)
MAX
MIN
0.3
0.5
1.0
200
50
STEREO
L + R
+
200
150
100
HPF
LPF
50
80
80
100
150
CONTROL
INPUT SELECTOR
L
A
A
A
B
FREQUENCY(Hz)
LPF
OFF
FILTER
HPF
200
50
200
150
100
HPF
LPF
50
80
80
100
150
INPUT
SENSITIVITY(V)
MAX
MIN
0.3
0.5
1.0
OPERATION
GND
MONO
MONO(Lch)
STEREO
L + R
R
LINE IN
A
B
@
#$
!
0
9
8
% ^
A
B
A
B
SPEAKER LEVEL INPUT
R
L
LEFT
RIGHT
SPEAKER LEVEL INPUT
LEFT
BRIDGED
RIGHT
A
B
A
B
SPEAKER OUTPUT
BRIDGED
R
L
POWER IN
FUSE(30A)
BATT
P.CON(REMOTE)
GND
15
2346
7
Amplifier A
Amplifier B
1 Fuse (30 A)
2 Battery terminal
3 Ground terminal
4 Power control (REMOTE) terminal
5 Amplifier A speaker output terminals
6 Amplifier B speaker output terminals
7 Speaker level input terminals
8 FREQUENCY control
When the FILTER switch is set to the HPF (High-Pass Filter) or LPF (Low-Pass Filter) position,
the threshold frequency can be adjusted with this control.
9 FILTER switch
High-pass or low-pass filtering can be applied to the speaker output according to the setting
of this switch.
0 OPERATION switch
The amplification methods of the signals input to amplifiers A and B can be selected
independently according to the setting of this switch.
5
· STEREO position:
The amplifier can be used as a stereo amplifier.
· L+R position:
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.)
! 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.
@ RCA cable ground lead terminal
# INPUT SELECTOR switch
This switch selects the input method of the signals to be amplified by amplifiers A and B.
· AB position:
Amplifies both of the signals input to amplifiers A and B.
· A position:
Amplifies only signal input amplifier A with both amplifiers A and B.
$ Amplifier A LINE IN terminal
% Amplifier B LINE IN terminal
^ LINE OUT terminal
These jacks output respectively the signals input to amplifiers A and B. They always output
the stereo signals regardless of the position of the OPERATION switch.
NOTE
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 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
MAX
MIN
0.3
0.5
1.0
(W)
25
15
10