ENGLISH
CLEANING THE APPLIANCE:
Clean by wiping with a cloth slightly dipped with water. Avoid getting water inside the unit.
Do not use volatile liquids such as benzene or thinner which will damage the unit.
Clean the ventilation holes regularly with a vacuum cleaner. This increases the cooling capacity of the
amplifier fans and helps preventing temperature overheat.
CONNECTIONS
Be sure to turn off the unit before you make changes to the wiring. Use good quality signal cables to ensure
excellent audio quality. For example use JB cables with order codes: 7-0061 (XLR/XLR L=1m) or 7-0063
(XLR/XLR L=5m). For the speakers we suggest using the Speakon
for example JB order codes: 2-0505 (L=5m) or 2-0510 (L=10m).
FUNCTIONS (FRONT)
1. POWER LED: This white led is on when you turn the amplifier on using switch(2).
2. MAINS SWITCH: Used to turn the amplifier on and off. A few seconds after switching on the amplifier it
is ready for operation.
3. GAIN CONTROLS: These potentiometers are used to control the input sensitivity of the amplifier. Each
channel has its own control.
You can use these controls to set the maximum sound level of your setup:
Turn both controls on the amplifier (3) to the left.
Put on some music on and make sure the VU meters on your mixer are at 0dB. (from time to time
the red zone is lit)
Set the Master output from your mixer to maximum.
Open the Gain controls from the amplifier (3) until the maximum desired sound level is reached.
Make sure nobody can reach the Gain controls of the amplifier or install the plastic cover (4).
You have just set the maximum level the DJ is able to produce. Your neighbors will be glad... (in some
cases the DJ is not )
Note: In Mono and Bridge mode, only the gain control of the left channel is used to adjust the input
sensitivity.
4. PLASTIC COVER: if you don't want people to mess around with the input level of the amplifier, just
install the supplied plastic cover, using the provided allan key. All indicators are still visible but the input
level can't be changed.
5. SIGNAL LEDS: these LEDs indicate that a music signal is present at the inputs.
6. LIMIT LEDS: Lit on just before the maximum, distortion free, output level of the amplifier. They indicate
that the internal limiter starts working. The limit LEDs may turn on shortly from time to time but they may
certainly not turn on for longer periods. In this case you have to turn the output level down!
7. AUDIO PROTECT LED: is on when the speakers are disconnected from the amplifier. This occurs in the
following situations:
During the first seconds after switching on the amplifier.
When the temperature of the power stage becomes too high.
In case of a technical defect: DC protection, overload, short circuit, ...
While switching the amplifier off, the "protect led" turns on for a short time.
8. POWER PROTECT LED: is lit for 3 to 4seconds after you turn on the amplifier, this is normal. During
operation this LED will be lit when a problem is detected in the power supply of the amplifier. When this
occurs, please turn off the amplifier.
9. OPERATION MODE LEDS: These LEDs indicate the operation mode switch (14) on the rear panel is
used to choose one of these 3 possible modes:
STEREO MODE: This is the most common mode, both channels are working separately.
JB SYSTEMS
®
OPERATION MANUAL
®
compatible outputs. Suitable cables are
3/34
AMP-series
ENGLISH
MONO MODE: Basically this is identical to stereo mode but the inputs of both channels are linked
so the output will be mono. In this case you only need to use the input of the left channel to drive
both output channels.
BRIDGE MODE: Both channels are linked in "bridge mode" to obtain a mono output with much
higher power.
10. VENTILLATION FANS: during its operation the amplifier produces heat that needs to be dissipated. The
fans inside the amplifier must be able to evacuate the heat in the most effective way. Therefore is it very
important not to cover any of the ventilation openings as this may result in overheating. Clean the
ventilation holes regularly with a vacuum cleaner. This increases the cooling capacity of the amplifier
fans and helps preventing temperature overheat.
FUNCTIONS (rear)
11. XLR inputs: You can connect these balanced inputs to balanced and unbalanced line level audio
sources (example: DJ-mixer):
Balanced source: Use good quality XLR/XLR balanced audio cables.
Example: JB Systems 7-0061 (XLR/XLR L=1m) or 7-0063 (XLR/XLR L=5m)
Wiring of the XLR connector: PIN1: GND PIN2: pos+ PIN3: neg-.
Unbalanced source: Use good quality XLR/cinch audio cables.
Example: JB Systems 2-0445 (XLR/cinch L=1.5m)
12. BALANCED XLR OUTPUTS: Can be used to send the signal to the next amplifier. Pin1: signal ground,
Pin2: signal+, Pin3: signal -
13. INPUT SENSITIVITY switch: With this switch you can perfectly adapt the input sensitivity of the
amplifier: 0,775V; 1,0V or 1,44V.
14. OPERATION MODE switch: Used to set the operation mode of the amplifier. The most common
operation mode is "stereo". If you need more power, you can operate the amplifier in bridge mode. Refer
also to point 9 and "HOW TO USE" for more information.
15. LOW CUT FILTER switch: eliminates low frequencies under 75Hz. Can be used when small speakers
are connected, these cabinets often don't support very low frequencies.
16. GROUND LIFT switch: In some cases nasty hum noises can occur due to ground loops in your setup.
Setting the Ground lift switch to the position "lift" breaks the ground loop between the amplifier and the
chassis grounds of various other components in your setup. As a
result the hum noises disappear.
17. L+R SPEAKON OUTPUTS: use these Speakon
connect your speaker cabinets in stereo or mono mode. Wiring of
these connectors is as follows:
POS(+) = Speakon connector PIN1+ and PIN2+
NEG(-) = Speakon connector PIN1- and PIN2-
18. BRIDGE SPEAKON OUTPUT: use this Speakon
connect your speaker cabinet in bridge mode. Refer to points 3 and 12 for more information. Wiring of
this connector is as follows:
POS(+) = Speakon connector PIN1+ and PIN2+
NEG(-) = Speakon connector PIN1- and PIN2-
19. POWER input: Use the supplied power cable to connect the amplifier to the mains. This connector also
holds a 20mm glass fuse. Always replace a blown fuse by another with exactly the same specifications.
(fuse specifications can be found on the rear panel, next to the power input connector)
JB SYSTEMS
®
OPERATION MANUAL
®
connectors to
®
connector to
4/34
AMP-series