CROSBY
STEREO POWER AMPLIFIER
REVISION P
R
A – SEPTEMBER 2017
Copyright © 2017, M2Tech Srl
15
M2Tech
www.m2tech.biz
6. Bridged Mono Mode
The
CROSBY
is capable of 60W per channel on 8 Ohms speakers. This is quite enough for
normal level listening in a living room with medium- or high-sensitivity speakers. Anyway,
set-ups using low-sensitivity speakers, particularly in large rooms with curtains, carpets or
moquette, may require more power.
To achieve this, the
CROSBY
may be set to operate in mono, bridging the two channels to
drive a single speakers. This way, the
CROSBY
is able to deliver up to 180W on 8 Ohms
speakers, and up to 400W on lower loads.
Of course, two
CROSBY
are required to drive two speakers when the bridged mono mode is
selected.
To activate the bridged mono mode, set the mode selector switch (Fig. 2, 8) to “BRG”,
connect the input signal on the left input connector (RCA or XLR, according to the chosen
inputs) and connect the speakers cables to the two positive output binding posts (Fig. 2,
11): positive to the left red one and negative to the right red one. The two black output
binding posts are unused in this setting
WARNING: when bridged mono mode is selected, none of the used (red) output
posts is connected to ground. Shorting any of the two posts to ground will activate
overcurrent protection and could lead to amplifier damage.
WARNING: The above settings and connections must only be done when the
CROSBY
is switched off!
7. Trigger
The
CROSBY
accepts trigger signals, 5V
DC
to 15V
DC
. A trigger signal can be used to
automatically activate the
CROSBY
by a preamplifier, so that all the system is powered on
and off by the preamplifier’s remote control. Trigger must be activated by the related
trigger enable switch (Fig. 2, 10), and the rear panel switch (Fig. 2, 14) must be in the on
position all the time.
8. Overload and Protection
The
CROSBY
is provided with advanced protection circuitry which senses any excess of
temperature or delivered current that may damage the power stage. When any potentially
dangerous event occurs, the protection circuits cut signal and turn the related LED’s on
(Fig. 1, 1 and 4).
Should this happen, turn the
CROSBY
off to allow for lowering its temperature, check for
proper output cables connection, lower the volume and switch the
CROSBY
on again. If the
overload indication persists, then the amplifier may be damaged and requires servicing.
