Certon M21 User’s Manual
5
Installation
Place the M21 on a stable surface. The unit has a self-resetting heat-switch, however:
Do not place the amplifier on a thick cloth or carpet, as ventilation would
be obstructed. Do not place in a confined area. Clearance should be allowed for heat
dissipation on the top and sides of the enclosure.
The M21 is equipped with a mains power switch (1) at the back of the unit.
During installation, keep the power switch in the “off” position.
Firmly attach all wires. Attach the loudspeaker cables to the positive and the negative
loudspeaker binding posts (2) of the M21. Pay attention to the phase. In general, the positive
terminal of the loudspeaker should be connected to the positive binding post of the amplifier,
and the negative terminal of the loudspeaker should be connected to the negative binding post
of the amplifier. Tightly secure the terminals. The M21 is non-inverting.
Do not short-circuit the loudspeaker terminals. Protection circuitry within
the amplifier will protect the unit from most overload conditions, but short-circuits
may seriously harm your M21. It is recommended not to use loudspeakers with a
nominal impedance of less than 4 ohms.
It is advised not to use highly capacitive loudspeaker cables, as this reduces
the phase margin of the amplifier and may potentially cause failure.
M21 has both RCA-type and XLR inputs. Attach an RCA-type or XLR signal cable between
the audio input (3,4) of the M21 and your pre-amplifier, home-theater processor or
corresponding unit. The RCA-type connector offers unbalanced operation, while the XLR
connector offers balanced operation. Be sure to put the toggle switch (5) in its appropriate
position.
Do not connect both RCA-type and XLR cables simultaneously, as this may
harm your pre-amplifier, home-theater processor or corresponding unit.
Be sure not to connect the audio input of the M21 to a line output. Doing so
may cause damage to your loudspeakers and your hearing.
