8.
Power Supply
8.1
Mains Supply and Power Supply with
i
CVP® Technology
The devices feature an active power factor correction circuit (PFC). Therefore the amplifier will burden the mains
supply almost like an ideal, purely ohmic load. This means that voltage and current flow are in phase. Only this way
you can draw maximum power from mains with almost no reactive power. Thus mains will be saved and the
automatic circuit breaker not unduly burdened. Furthermore, the mains input current is permanently controlled
internally by an intelligent microprocessor. So before an automatic mains cut-out can trip due to an excessive current
load, the output power of the amplifier will be reduced and then instantly raised again if permitted. However, during
operation this will not even occur with very low loudspeaker impedances and heavily compressed music material. All
limiter LEDs will light up together if the output power is reduced due to an imminent mains overload.
A reliable operation on 16 A (Class B) automatic mains cut-outs is permanently ensured, as long as the circuit
breaker complies with the current regulations. For systems which serve the needs of personal safety at least class C
circuit breakers must be used for safety reasons. A reserve will increase the system safety.
The unit can be operated already from 75 VAC and has a wide input voltage range. With high continuous output
powers a sufficiently stable mains voltage must be applied. The minimum and maximum values are printed on the
rear panel of the unit and listed in the chapter on technical data.
If other devices are connected to the same mains, make sure that the internal line resistance (in consequence of
undersized mains cables, cable drums etc.) is not too high. Otherwise it can happen that other loads connected
hereto will show malfunctions due to momentary mains voltage fluctuations. When using cable reels or other
extension cables, the cable must be unwound completely. It is advisable to use a minimum copper cross section of
2.5 mm2 . For greater distances you need to contact authorised and skilled experts.
As soon as the unit is connected to the mains voltage, it is in standby mode. Only after the ON / Standby switch (front
panel) is set to the ON position, intelligent protection circuits will perform a software-controlled check of all internal
conditions before the unit will turn itself on completely (boot procedure). After a few seconds the amplifier will be
ready for work and slowly increase the gain settings to the preset values.
8.2
Operation on Generators
When operating the amplifier on a generator, it must be taken into account that a high momentary mains current draw
may occur, depending on the connected loudspeakers, the operating modes (bridge / single-ended), the drive level of
the amplifier, the audio signal and the limiter settings of the signal controller. With high pulse-like output powers,
undersized generators (too small a gyrating mass and too feeble peak current capability) can be slowed down to a
halt. If this problem occurs and there is no other, more stable mains supply available, you may check two things as a
possible interim remedy:
a) Adjust the limiters (RMS and Peak Limiter) in the signal path to more sensitive settings and gradually lower the
maximum output voltage settings on the controller.
b) Use bridged channels (bridge mode) in single-ended mode. This will reduce the maximum output power to a ¼ of
the initial value, thereby also lowering the mains current draw. Caution: Mind the pin assignment of the SpeakON
socket!
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