
www.pulse-audio.co.uk | APB Series User Manual
Rear Panel
12. Cooling fan 18. Parallel/Stereo/Bridge mode switch
13. Parallel signal outputs 19. Speaker outputs 1 and 2
14. Signal inputs 20. 4mm binding post speaker outputs (inc. Bridge)
15. Ground lift switch 21. IEC mains inlet
16. Compress (clip limiter) switch 22. Mains fuse holder
17. Input sensitivity switch 23. Cooling fan
Operation
Connect speaker cabinets to channel outputs using good quality leads via the SPK connector or binding posts and ensure
that the combined load on each channel is no lowerthan 2 .
For speaker loads connected in parallel
8 + 8 = 4 total
4+ 4 = 2 total
8+ 8 + 8 + 8 = 2 total
Both channels can be used to drive a single load at the combined volume of each by switching to BRIDGE mode. In this
mode,the input is on channel 1 and output from CH1 SPK connecter (pins 1+ and 2-
indicated on the rear panel - WARNING - Minimum load for bridge mode is 4
Connect each signal input from mixer or other line level source via the XLR connectors on the rear panel using good
quality signal leads. Depending on output level of the mixer, select the appropriate sensitivity on the rear panel.
For protection in high power situations, the onboard COMPRESS function may be switched in to protect from overload.
In situations with excessive mains hum coming through the speakers, it may help to switch the GROUND to the LIFT
position. This is may help in some situations but otherwise, it is preferred to be switched to GND.
XLR inputs and outputs for each channel are wired in parallel, allowing signalto be carried forward tofurther amplifiers.
Connect the amplifier to a mains outlet, ensuring that the IEC lead is earthed, in good condition and connected securely.
-
which makes some checks before engaging power to the amplifiers, which may take a few seconds.
required level (normally3/4) and then gradually increase the signal levelfrom the mixer or sound source until sound can
be heard through the speakers and then continue increasing up to the required level.
yellow
output is reaching clip level. If the red CLIP LEDs illuminate more than very briefly, reduce the volume until they hardly
light up at all.