Keene KLAB20DB Operational manual

Installation & Connection
Installation should only be carried out by a qualified installer or electrician, as a certain amount of
electrical knowledge is assumed.
Mounting
The 25mm depth will allow installation into standard UK 2-gang boxes, which may be galvanised
metal for installation in solid walls, or plastic drylining (with lugs) or surface mount box or trunking
system.
Wiring
In order to make a reliable and safe connection without short circuits it is recommended that the
speaker cables and line input signal cables are prepared and tinned prior to connection, with no
more than ¼” or about 7mm of tinned wire extending out of the insulation.
Power
The amplifier requires a power supply of 12v to 18v DC centre positive and a minimum current of
3500mA. If you are not using the recommended psu please verify that the supply is correct BEFORE
connection. If using the recommended supply we suggest that it is connected in accordance with
current wiring regulations. The amplifier can also be powered from a 12v car battery but NOT di-
rectly from a car battery charger as this would damage the circuitry. Do not install near any heat
sources such as radiators, stoves, or other apparatus that produce heat. The mains connection
should be via a fused and switched mains outlet such as order code SWL1.
Environment
The KLAB20DB is not IP rated for use in a damp environments but if due care is given to positioning
of the amplifier and supply then it can be used in zone 3 installations. Please use a qualified electri-
cian operating to current regulations if you intend to use this unit in a bathroom.
Overview
The Keene KLAB20DB is a compact, powerful stereo
amplifier built onto a standard size UK double gang
wall plate. It provides 20W (RMS per channel) of
amplification eliminating the need to make space for a
conventional amplifier. It draws it’s own power from an
externally located mains adaptor and can be
controlled by push buttons integrated into the front
panel membrane and also by infra red remote. It can
be switched between four audio sources; an
integrated FM radio, rear line inputs, bluetooth and a
front panel 3.5mm jack input. The amplifier uses class
D digital circuitry for maximum efficiency and
generates very little heat. The amplifier only requires
25mm depth and so may be either flush or surface mounted.
IMPORTANT - Please Read!!!
The front panel membrane has two tabs that can be flexed outward
to allow access to the panel fixing screws. Once fastened in position
and tested the backing paper can be peeled off and the tabs fixed
down flush to conceal the screws. ONLY perform this operation
once the installation has been tested and found to be satisfactory.
Once stuck down these tabs cannot be removed without damage to
the front panel.
Replacement front panels are available, (part number KLAB20DBFP)

Loudspeakers
Connect the loudspeakers being careful to keep both left and right phase connections the same. For example
if you’ve connected the left speaker positive to “A” and negative to “B” make sure that the right speaker
positive also goes to “A” and negative to “B”. Please note that the amplifier is fully bridged so there is NOT a
common ground or return connection. The recommended minimum speaker impedance is 4 ohms on each
channel. If driving 2 speakers or more on each channel use them in series if they are both 4 ohms or in
parallel if they are both 8 ohms. Note the speaker corresponding to the left input is actually on the right hand
terminals in the amp as viewed from the front.
Line input
Connect the input signal cables using tinned screened cable. Connect the screens to the 2 centre connections
and the 2 signal wires (centre cores) to the top and bottom connectors. Note all the connectors are of the
superior rising clamp style so that they make a sound connection without biting through the copper of the
cable.
Aerial
The FM radio requires a 75ohm aerial for operation. The bare wire ends of the supplied aerial cable should be
connected to the terminals on the PCB and the other end arranged in a "T" shape as best as possible within
wall or ceiling. If the cable needs to be extended then use similar sized 75ohm impedance cable. If you wish
to connect to an external FM loop aerial then use coaxial aerial cable such as KBL 7. Polarity of the supplied
aerial is not important, although if using coaxial cable then connect the screen (ground) to the right hand
terminal closest to the PCB screw.
Double check all connections and, if all is well then fasten the panel into the mounting box. Switch on the
power source and observe the LED's. If all is well the blue "Bluetooth" LED should be flashing slowly. Press
the “power” button on the front panel once (or press power on the remote control) and the blue LED should
change to red to indicate the unit is in standby. Power on again and cycle through the inputs. If there are no
unexpected sounds then it's probably all connected correctly and it should be safe to proceed to the operation
instructions. Do not fasten down the tabs until you are certain that everything is working as it should!
Installation continued..
DC input
12-18v
3500mA
Reserved for
programming
Line input
terminals
(as viewed)
+ Right
- Right
- Left
+ Left
FM aerial
connection
75 ohm
Right
speaker
connection
Left speaker
connection
Connections for Power, Line Input and Loudspeaker Outputs are located on the rear PCB.
Pre-amp line
output for use
with slave
amplifier
Note that the loudspeaker and line input screw terminal blocks can be pulled upwards and detached
from the PCB to make connection and installation easier.

Volume
There are 256 steps to the volume control from a minimum volume of 0 to a maximum volume setting of
255. These are accessed by pressing the volume up and volume down buttons. The 10 number keys from
zero (minimum) to 9 (maximum) provide quick way of selecting a range of preset volumes within this range.
Please note that the volume control system used does not go to absolute zero volume, the mute button is
provided for when you require the unit to produce no sound.
Operation. Front panel overview
Stores the current radio
station to the current
location.
Switches between
Bluetooth, radio, PCB
line input and jack
Mutes the output.
Switches between
standby and on.
Seeks up to the next
radio signal.
Switches between
stored radio stations.
Volume up.
Volume down.
3.5mm jack socket input
Receiver window for
the supplied IR
remote control.
Status indicator
LED's
Bluetooth mode
In Bluetooth mode a slow flashing blue LED indicates that no Bluetooth device is connected. F5 will turn
pairing on and the blue LED will flash more quickly. F6 will turn pairing off (and the blue light will flash slow
again). If a Bluetooth device is currently connected pressing F5 will also disconnect from that device.
Pressing F4 will turn Bluetooth auto connect (to previously paired devices) on and off. The Bluetooth LED
will flash red once for auto pairing on and twice for auto pairing off. If your device request a pairing code
please enter 1234
When a device is connected: F1 sends a play/pause command to the device. F2 sends stop command to
the device. The large up and down buttons (above/below mute) send next and previous track command to
device.
The default Bluetooth ID is KeeneBlue. If you have more than on Bluetooth amplifier you may wish to
change the ID to make each amplifier unique. This is achieved by performing a factory reset as detailed
later in this document.
Notes
When the unit receives power it will
revert to the last used input. In the
event of a power failure the amp will
come back on in to standby mode and
will remember the last stored
parameters.
It is safe to leave the amp in standby
as very little current (less than
100mA) is used in that mode. In
standby only the Red power LED will
be illuminated. This is the normal
method of switching off.

Power on/power off
Numbers 0 to 9 give
pre-set volume levels.
standby
Increase/decrease
volume.
Mute
F1 = radio seek (up)
F1 = Bluetooth pause
F2 = Bluetooth stop
F2 = enter / exit setup
mode
F3 = radio seek (down)
F4 = store (when in
normal mode)
F4 = Bluetooth auto
pairing on/off
F5 then number key =
go to preset radio
station. Performs reset
if in setup mode.
F5 Bluetooth pairing on
F6 = Bluetooth
pairing off
Bluetooth next and
previous track.
Radio station preset
up/down.
Adjust parameters
when in setup mode
Cycles through the
inputs; Bluetooth,
radio, line, jack socket
Adjustment procedure for bass, treble, balance and loudness:
To enter setup mode press F2 and hold for 3 seconds.
Bass, treble, balance & loudness can now be adjusted. F4 cycles through these parameters and the radio
preset up/down (above/below mute) will adjust the levels. To exit setup procedures press F2 again. To store
the current settings to memory so they will be saved when the KLAB20DB is switched off and on again exit
setup mode by pressing F2 and then press F4. Note - setup mode will be exited automatically (without
storing) if no key is pressed within four seconds.
When in setup mode the LED's will illuminate as follows:
Adjust Bass
Adjust Treble
Adjust Balance
Adjust Loudness
When making adjustments in setup mode:
The "mute" key will reset the parameter being
adjusted
The "F1" key will reset all four parameters
The "F5" key followed by a number will perform
a factory reset including erasing any stored
radio stations. Please see details on the next
page.
Tuning and storing radio stations
To store a radio station first choose a memory location, for example to store to location four, press F5 then
four. This makes number four the current active memory location. Now press seek (F1 up or F3 down) until
the tuner settles on the station you like. Now press and hold F4 until the FM radio LED flashes green and
the current station will then be stored to location four. Repeat for each location (0 through 9) storing as
desired.

Factory Reset - Bluetooth ID - FM Radio presets
The factory reset procedure will restore all settings to factory default including any changes that have been
made to stored radio stations, balance, treble, bass and loudness. The reset will also affect the Bluetooth
ID and the preset FM radio stations.
The Factory reset procedure is as follows:
1) Enter setup mode by pressing “F2” for three seconds until all the LED’s illuminate.
2) Press F5
3) Within two seconds press a number between 0 and 9
4) All four LED’s will flash to confirm and the unit will restart.
Dependant upon the number chosen the Bluetooth ID will change as follows:
0 = Keeneblue (factory default)
1 = KeeneOne
2 = KeeneTwo
3 = KeeneThree
4 = KeeneFour
5 = KeeneFive
6 = KeeneSix
7 = KeeneSeven
8 = KeeneEight
9 = KeeneNine
Important - when you scan for Bluetooth devices the ID is usually stored along with its unique MAC
address. When you change the ID from say KeeneOne to KeeneTwo it may well still appear in your device
list as KeeneOne if this had been previously scanned and discovered. This may be the case even if you
have not previously paired with it. To force the name to change you will need to pair to the device, then
perform a “forget this device” or “unpair”, then rescan and re-discover it under the latest device ID.
If, after performing a reset the device start up with a single flashing red LED then please disconnect the
power supply, wait for five seconds and then reconnect.
The number chosen will also load the preset FM radio stations as follows:
FM default 0 - E Midlands
[0] = Smooth Radio
[1] = BBC radio1
[2] = BBC radio2
[3] = BBC radio3
[4] = BBC radio4
[5] = Classic FM
[6] = Capital FM
[7] = Radio Derby
[8] = Radio Nottingham
[9] = Trent FM
FM default 1 - London
[0] = Smooth Radio 102.2
[1] = BBC radio1 98.8
[2] = BBC radio2 89.1
[3] = BBC radio3 91.3
[4] = BBC radio4 93.5
[5] = Classic FM 100.9
[6] = KISS FM 100.0
[7] = Virgin 105.8
[8] = Capitol 95.8
[9] = Magic FM
FM default 2 - South
[0] = London
[1] = BBC radio1
[2] = BBC radio2
[3] = BBC radio3
[4] = BBC radio4
[5] = Classic
[6] = Absolute
[7] = Capitol
[8] = XFM
[9] = Magic
FM default 3 - Home Counties
[0] = Berks
[1] = BBC radio1
[2] = BBC radio2
[3] = BBC radio3
[4] = BBC radio4
[5] = Oxford
[6] = Solent
[7] = Classic
[8] = Absolute
[9] = ????
FM default 4 - South East
[0] = Kent
[1] = BBC radio1
[2] = BBC radio2
[3] = BBC radio3
[4] = BBC radio4
[5] = Surrey
[6] = Sussex
[7] = BRFM
[8] = Classic
[9] = Arrow FM
FM default 5 - North West
[0] = Manchester
[1] = BBC radio1
[2] = BBC radio2
[3] = BBC radio3
[4] = BBC radio4
[5] = Lancs
[6] = MerseySide
[7] = Classic
[8] = Galaxy
[9] = Liverpool
FM default 6 - East
[0] = Essex
[1] = BBC radio1
[2] = BBC radio2
[3] = BBC radio3
[4] = BBC radio4
[5] = Cambs
[6] = Norfolk
[7] = Northampton
[8] = Suffolk
[9] = Classic
FM default 7 - Yorks
[0] = Leeds
[1] = BBC radio1
[2] = BBC radio2
[3] = BBC radio3
[4] = BBC radio4
[5] = Sheffield
[6] = York
[7] = York coast
[8] = Air
[9] = Sheffield live
FM default 8 - Wales
[0] = BBC Wales
[1] = BBC radio1
[2] = BBC radio2
[3] = BBC radio3
[4] = BBC radio4
[5] = Cymru
[6] = Champion FM
[7] = Marcher
[8] = Coast
[9] = classic
FM default 9 - N Ireland
[0] = Ulster
[1] = BBC radio1
[2] = BBC radio2
[3] = BBC radio3
[4] = BBC radio4
[5] = Foyle
[6] = CityBeat
[7] = cool
[8] = Antrim
[9] = DownFM
We apologise if your area or
favourite stations are not
covered. This was intended as a
quick installation aid and it is very
easy to tune and store your own
preferences as required.

Power output (15v supply): 20W RMS per channel into 4ohms
Total Harmonic Distortion + Noise: 0.15%
(4ohm load, 1KHz, 8W power)
Bandwidth: 20Hz to 22KHz Passive limitation built in
Power Supply: 10V to 18V (absolute max 18V DC) minimum
current 3.0A. Connection via a 2.1mm DC connector
centre positive, auto mute on under voltage.
Fuse: self resetting 3A built in – to clear remove power for
at least 20 seconds, clear fault and reconnect
Amplifier topology: full bridge mode all speaker connections are live
( no common ground connection)
Recommended minimum speaker
impedance: 4 ohms per channel
Absolute minimum speaker impedance: 3 ohms per channel
SNR: 98dB
Voltage gain: 33dB
Input required to produce full output: approx 775mV
Power output (12v supply): 15W RMS per channel into 4ohms
Specifications:
Part numbers you may find useful:
Architectural Wall/Ceiling mount loudspeakers
5 1/4" 25W [CMS5U]
8" 30W [CMS8U]
Switched Spur outlet
An MK style switched fused spur outlet, ideal for making a safe connection to the KLAB20D power supply.
[SWL1]
Power supply (input: 100-240v AC, Output: 15v DC 4.0A)
[KLABPSU]
Replacement front Fascia panel
[KLAB20DFP]
3.5mm stereo jack to 3.5mm stereo jack front panel input cable 1.2M
[KLDE6]
Loudspeaker cable 42 strand OFC
[KBL31]
Additional remote control
[KRC1]
Old Hall Mills Business Park Little Eaton Derbyshire DE21 5DN
Telephone [phone] Fax [phone]
http://www.keene.co.uk
http://www.syncblaster.com