Cautions Regarding Handling
Never connect the speaker output terminals to any ground. Both speaker
terminals carry an active signal due to the full balanced circuit design of
Be careful when connecting active subwoofers or similar devices to the
speaker terminals. A short circuit to the ground may result in damage to
HD53N or a broken fuse.
The DC voltage at the speaker and the balanced headphones output
terminals is not 0 when measuring related to ground. However, the differential
DC voltage from (+) to (-) terminals is nearly 0 and thus harmless to speakers
Audiophile amplifiers produce heat! Make sure to leave enough space
around HD53N (at least 15cm) for keeping the air circulating. Make sure you
never cover the air vents on the top and bottom plates, which could result in
an overheating. It is recommended to use HD53N in a low-dust environment.
In case of overheating (over approx. 65
℃ ) HD53N will cut off the operating
power automatically. In this case it is suggested to put the main power switch
to “OFF” position. Otherwise HD53N will power ON again after cooling down.
HD53N requires no periodic maintenance and contains no user-serviceable
parts. Contact your dealer or an authorized CEC service center for inspection
and repair in case of malfunction.
If the surface of the HD53N enclosure is soiled, wipe with a soft cloth or use
diluted neutral cleaning liquid. Be sure to remove any ﬂ uid completely. Do not
use thinner, benzene, alcohol, chemical cloths or bleaching agents as these
may damage the surface of the HD53N enclosure. Also avoid using aerosol
insecticides near the unit.
If dust should have accumulated on the unit, remove it with stick tape (e.g.
Scotch tape). Make sure not to touch the enclosure with any tools or other