Klein + Hummel
M 52 (D)
Page 3
The loudspeaker is protected from accidental application of an incorrect polarity of the DC
voltage. The mains input fuse is a slow blow 800 mA and is accessible from the outside
(next to the main power On/Off switch). The external power supply input fuse is an SB
3150 mA and is located on the inside of the cabinet. To change this fuse:
•
Turn off the loudspeaker and disconnect the mains power and signal cables.
•
Open the cabinet (four screws on the edge of the back panel).
•
Locate the fuse holder and change the fuse for a new one with the correct
specification (slow blow 3150 mA).
•
Close the back panel and reattach the mains power and signal cables.
•
Power up the loudspeaker and check that the front panel light is correctly illuminated.
For mains AC power:
The power On/Off
power On/Off
power On/Off
power On/Off switch on the back panel turns the loudspeaker on and off. If the
volume control
volume control
volume control
volume control on the front panel is rotated fully anti-clockwise the loudspeaker is placed
into standby mode. If the back panel mains switch is on, standby is indicted by a red light
on the front panel. Otherwise it is green (loudspeaker is ready to be used) or off
(loudspeaker is switched off on back panel or no power applied to the external or mains
connectors).
For the external power supply:
The 4-pin XLR input bypasses the main power On/Off
power On/Off
power On/Off
power On/Off switch. There is no standby mode
when there is an external power supply. The LED lights green when the external power is
applied.
Analog
Analog
Analog
Analog Input
Input
Input
Input S
SS
Stage
tage
tage
tage
The input stage
input stage
input stage
input stage is a 10 k
Ω
transformer balanced type on a female XLR socket.
Pin
Pin
Pin
Pin
Signal
Signal
Signal
Signal
1
Audio Ground
2
Positive
3
Negative
If there is a humming or buzzing sound coming from the loudspeaker, first check it is not
the loudspeaker by disconnection the input signal cables. If the noise goes away it is not
the loudspeaker itself and so the noises must be coming from the cabling (mains power or
signal) or the source. If unbalanced cables are being used, specially wired cables can
increase the loudspeaker’s immunity from these external noises – see picture below.
