Audio Research Reference 750 SE, Manual

Page: 7 / 18

7
Installation
In your system
To insure normal component life and safe
operation this unit must be operated only in
an upright position. Adequate airflow and
proper cooling can occur only if there are no
restrictions above and behind the unit and on
either side. If the optional cover is installed,
be sure that airflow to the 12V D.C. cooling
fan is not blocked.
The special non-marring elastomer feet
provide adequate spacing and stability only
on a smooth, hard surface, and also assist to
isolate the amplifier from spurious vibrations.
For upright stability and best performance,
never operate the unit while it is sitting on a
soft surface such as a thick rug or carpet.
Due to its weight, this amplifier must be
supported on a surface specifically rated for
such a load. Check with the manufacturer of
your support system to be sure it is rated to
handle this weight.
If the unit is to be operated in an enclosure
such as an equipment rack, make certain that
adequate airflow above and to each side of
the unit is provided.
The ‘ambient’ operating temperature should
never exceed 120° F or 49° C. Improper
installation will cause premature tube failure
and will affect your warranty, as well as the
service life of the unit.
It is normal for a vacuum tube power
amplifier to run quite warm, and if used
for prolonged periods, hot to the touch. All
components within are, however, operated
at safe, conservative levels and will not be
improperly affected thereby, providing the
requirements outlined above are adhered to.
Installation of Optional Cover
To install the optional fan-cooled tube cover,
first align the front of the cover with the top
front edge of the amplifier, making sure the
fans are positioned at the rear. Note that
there are five holes along the top edge of
each side panel; these should match up with
corresponding holes along the bottom side
edges of the tube cover. Before settling and
aligning the tube cover at the rear, insert the
12V D.C. plug attached to the fans into the
12V socket located at the back edge of the
anodized top plate. Then secure and align the
tube cover completely, insert supplied screws
and tighten moderately.
A Note about Vacuum Tubes
The vacuum tubes in your Reference 750 SE
have been burned in, tested and electrically
matched to provide the best performance
and reliability of your amplifier. That said,
vacuum tubes must be replaced from time to
time. The KT150 output tubes and the 6550
tube in the power supply of the Reference
750 SE should have an expected life of
approximately 2,000 hours, while the smaller
6H30 tubes should have a life expectancy
of approximately 4,000 hours. These life
expectancies are only approximate.