Ecleree MPA4-150, User Manual

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3.3. Ground Link switch
The “GND LINK” switch (26) purpose is to avoid ground loops caused when several
devices in the same amplification chain are connected to earth simultaneously. This switch
disconnects the electrical ground from the mechanical ground on the housing. In case of a
ground loop (humming noise) operate this switch or alternatively the corresponding switches on
the other devices connected to the chain.
3.4. Multi-function
Depending on the input switches on the MPA4-150 /4 -300 (27, 29, 30, 31, 33, 34),
located on the rear panel, four different amplification configurations can be achieved:
- Four mono amplifiers with following possibilities:
Four different mono inputs.
One common mono input for all.
One common stereo input for all.
- Two stereo amplifiers with following possibilities:
Two different stereo inputs.
One single stereo input for both.
- Two bridged amplifiers with following possibilities:
Two different mono inputs.
One common mono input.
Two different stereo input.
One common stereo input.
Combinations between mono, stereo and bridged amplifiers
On the rear panel you can also activate the high-pass and low-pass filters:
High-pass filter ON/OFF switch (28). The cut-off frequency lies at 160 Hz for
amplifiers 3 and 4 simultaneously or when operating in bridged mode. This filter cuts out all
frequency components under 160 Hz and passes the rest, being specially suited for connecting
the mid-range and high frequency speakers.
Low-pass filter ON/OFF switch (32). This switch activates a filter at channel 1 which
cuts out the frequency components above 160 Hz and passes the lower ones.
ATTENTION: Due to the fact that subwoofers require a considerable amount of
electrical power, channel 1 and 2 must be configured in bridged mode. If they are set to
stereo-mode, the system will not work properly, as the filter only affects the output of
channel 1.
Combining one bridged amplifier with switched on low-pass filter together with a
stereo amplifier with switched on high-pass filter turns your multichannel power amplifier into
an ideal equipment for clubs and other locations with a subwoofer, mid-range speakers and
tweeters.