User Guide

Active Studio Monitor O 110 Page 5
Position 0 = free standing
Position 1 = placement a short distance
before a wall
Position 2 = placement flat against a wall
Position 3 = placement in a corner of the room
1.5.2.2 MID Switch
If the loudspeakers are placed on the meter bridge,
a certain overemphasis in the midrange will
typically result. Next to the four-position switch for
room compensation which we just described,
there is another four-way rotary switch labeled
MID. The four switch settings are intended for the
following kinds of placement:
Position 0 = free standing
Position A = placement on a table top
Position B = free standing on the meter bridge
Position C = on the meter bridge between
other equipment directly on either
side, or built into a wall.
Note: Since it is not possible to list all possible
combinations of speaker placement and room
acoustics, we strongly recommend checking the
switch settings acoustically or by measurement.
The frequency response curves of both equalizers
are shown in Figure 12 in section 2, diagrams.
1.5.3 GROUND LIFT
Since the input is balanced, a ground loop hum
will rarely occur. In special cases or if the source
signal is unbalanced, it can become necessary
to separate the signal ground from chassis ground.
To do so, first unplug the mains cable from the
mains socket, of course, then unscrew and remove
the back panel, which has the amplifier electronics
mounted directly to it. Figure 4 shows the amplifier
circuit board below the XLR jack. The arrow is
pointing to a jumper, which by default bridges the
two pins. If you remove the jumper the signal
ground is lifted from the chassis ground. Of course
the chassis ground always remains connected to
the protective earth conductor.
Warning!
The protective earth conductor must
never be interrupted even for test
purposes! This may be dangerous to life!
1.6 Mains Power Fuse
Should you ever need to replace the power fuse,
please ensure (first of all that the unit is unplugged
from the mains!) and that only the following type
and value of fuse is used:
For 230-240 volts AC: 1 A Slo-Blo (5 x 20 mm)
For 117 volts AC: 2 A Slo-Blo (5 x 20 mm)
For 100 volts AC: 2.5 A Slo-Blo (5 x 20 mm)
1.7 Display Functions
The illuminated K+H logo serves as a status
display for the loudspeaker when the power
switch is on and the fuse is intact:
Continuous red:Normal operation, internal
supply of power is in order
Blinking red: Overload protection circuitry
engaged
If the light is blinking, this indicates that the
overload protection circuitry has been triggered.
Among the things that can trigger it are the
”scrubbing” of analog tape in cue - mode,
extremely bass - heavy signals or the sine - wave
signals that are used in performing measurements.
The protection circuitry limits the output power of
the amplifier to a level that is safe for the speaker.
If the output level should drop as in one of these
cases, check for the cause and, if necessary,
reduce the monitoring level.
1.7.1 Overload Protection
As we just described above, the protection circuit
limits the signal to safe levels. This occurs so
gradually, that under certain circumstances you
may not even notice that the protection circuitry
has been triggered and the signal is being limited
in dynamic range. But by moving an internal
jumper you can change how this circuit responds,
so that when it is activated, it will cause a clearly
audible drop in level (hard position). To access
this jumper, unplug the mains cable from the
mains socket, unscrew and remove the rear panel,
on the other side of which you will find the amplifier
Figure 4: Ground Lift Connection
!