2.5.5 Source 2x S/P-DIF, AES 3id
2.6 Mains and battery fuses
The mains fuse is to be found on the rear panel, close to
mains connector whereas the battery fuse is only accessible
after removing the rear panel. Before changing fuses all po-
wer sources have to be disconnected. Only the following
fuses 5x20 mm may be used:
mains 230 V AC
0.2 A slow blow
mains 117 V AC
0.4 A slow blow
mains 100 V AC
0.5 A slow blow
battery 12 - 14 V DC
2.5 A slow blow
2.7 Speaker placement
The loudspeaker chassis used in the M 51 D is magnetically
shielded, so you are free to set the speakers right next to a
video monitor without needing to worry about adversely
affecting the screen. The sophisticated M 51 D design gained
in an unified and neutral sound within the nearfield zone. Best
results are achieved within a hearing distance of 1 to 1.5 m.
Stereo pairs should be turned to the hearing area.
On the bottom there is a 3/8" threaded bushing for mounting
the M 51 D on a standard microphone tripod. The LH 11 table
mount bracket can be fixed to the two M6 threaded holes in
the sides and so allows rotation around horizontal and verti-
kal axis.
2.8 Ground lift
Since the input is transformer - balanced and floating, you
should rarely experience any hum. In unusual cases, or if the
source is unbalanced, it may be necessary to lift the connection
between signal ground and chassis ground (connected to
protective earth, PE), in which case you will find a wire bridge
inside the amplifier - see figure beside. On delivery the shown
connection is closed and can be opened if a hum interference
occurs.
Warning!
Never disconnect the protective earth (PE) of the mains
power cable from the chassis ground!
3. Operation
2.5.5 Source 2x S/P-DIF, AES 3id
2.6 Mains and battery fuses
The mains fuse is to be found on the rear panel, close to
mains connector whereas the battery fuse is only accessible
after removing the rear panel. Before changing fuses all po-
wer sources have to be disconnected. Only the following
fuses 5x20 mm may be used:
mains 230 V AC
0.2 A slow blow
mains 117 V AC
0.4 A slow blow
mains 100 V AC
0.5 A slow blow
battery 12 - 14 V DC
2.5 A slow blow
2.7 Speaker placement
The loudspeaker chassis used in the M 51 D is magnetically
shielded, so you are free to set the speakers right next to a
video monitor without needing to worry about adversely
affecting the screen. The sophisticated M 51 D design gained
in an unified and neutral sound within the nearfield zone. Best
results are achieved within a hearing distance of 1 to 1.5 m.
Stereo pairs should be turned to the hearing area.
On the bottom there is a 3/8" threaded bushing for mounting
the M 51 D on a standard microphone tripod. The LH 11 table
mount bracket can be fixed to the two M6 threaded holes in
the sides and so allows rotation around horizontal and verti-
kal axis.
2.8 Ground lift
Since the input is transformer - balanced and floating, you
should rarely experience any hum. In unusual cases, or if the
source is unbalanced, it may be necessary to lift the
connection between signal ground and chassis ground
(connected to protective earth, PE), in which case you will
find a wire bridge inside the amplifier - see figure beside. On
delivery the shown connection is closed and can be opened
if a hum interference occurs.
Warning!
Never disconnect the protective earth (PE) of the mains
power cable from the chassis ground!
