DO NOT REMOVE MAINS CONNECTOR GROUNDIT IS ILLEGAL AND DANGEROUSto Pin 1of the XLRs3 INSTALLATIONUSER MANUALVORTEX 6, 4, 2.6 and 200VP.133.4 CoolingUnder normal operation of the power amp, overheating should never be aproblem. The air is taken in from the front and out through the back. It is ofcourse essential that while the power amp is running air is able to circulatearound it freely.The efficiency of the cooling will depend on the immediate environment (e.g.an enclosed rack, direct sunlight) and on whether the front filter is clogged. Ifthe amp is installed in a case, the open area at the back of the case must be atleast 140 cm². This area should be in line with the amp.If this can not be achived a forced ventilation system has to be used.3.5 Ground LiftThe input signal ground (pin 1 for all 4 XLRs) is connected to the ground of themains supply. In order to avoid ground loops, this connection can be separatedvia a resistor. The ground potential of the power amp and the ground of theloudspeaker always remain connected to the ground of the mains supplyregardless of the setting of this switch.Removing or taping the mains connector ground is illegal and dangerous.3.6 Optional FeatureCould be activated with future released software versions.3.7 Mode IndicatorsOn the front panel there are two yellow LEDs to indicate the mode that is set.In stereo mode none of them will be lit. In Parallel-Mono the (PM) LED will be litand in Mono-Bridge, the (MB) LED will be lit.Amplifier in Parallel-Mono mode Amplifier in Mono-Bridge mode