Input Connections; Limiter Circuit; Output Connections - Ecleree MPA4-150 User Manual

3.5. Input connections

The signal input connections (20, 21, 22, 23) are electronically balanced XLR-3
sockets, with an input impedance higher than 20kΩ and a nominal sensitivity of 0dBV(1V).
Pin assignment:
The following diagram shows the connection of balanced and non-balanced audio
sources:
Some of the connection options for the and the corresponding switch settings are
described later in paragraph 6.3.
Depending on the chosen option, the SP indicators will only light for the active
channels.

3.6. Limiter circuit

This system is an always active protection inside the MPA series of amplifiers. The
ANTICLIP circuitry constantly analyses harmonic distortion caused by excessive signal excursion
at the power amplifier's output and automatically reduces the input level in order never to reach
distortion. The MPA4-400 amplifiers are delivered with the anticlip system adjusted at a threshold
of 1% THD (hard limiting). However, this value can be switched to a softer limiting (5% THD) via
an internal jumper (see figure ). In the MPA4-150, the anticlip is not configurable.
The great convenience of such a circuit in any kind of installation has to be
remarked: The clear advantage of a limiting system in front of conventional compressors is that
the former does practically not alter the dynamic range, acting only when the distortion threshold
is reached.
CAUTION: Changes on the ANTICLIP configuration have to be performed by a qualified
technician.

3.7. Output connections

The output section on the MPA4-150 / 4-400 rear panel holds 8 screw-type speaker
terminals (16, 17, 18, 19), two for each amplifier.
The attenuation controls and the output configurations are described later in
paragraph 6.4.
The cable which connects the speakers to the amplifier should be high quality and as
short and thick as possible. This is important when covering long distances; For up to 10m we
recommend a cable section not smaller than 2.5mm². For longer distances we recommend
4mm².
1. GROUND
2. PHASE (in phase with the output)
3. NON PHASE (inverted phase)
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