Owner`s manual

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5!
Vacuum Tubes and
Preparation for Use
Your Reference 150 amplifier is shipped
with the vacuum tubes packed in foam
blocks. These must be unpacked and
installed before you attempt to operate
the amplifier. Included are four
matched pair of KT120 output tubes,
and four 6H30 dual triodes used in the
input stage. Proceed according to the
following instructions.
Carefully remove each vacuum tube
from its protective foam and match its
location ‘V’ number (written on the base
of the tube) to the ‘V’ number printed
next to each socket. Firmly seat each
tube in its matching socket, taking care
to ‘key’ the tube pins to the socket
holes. Retain the foam blocks with other
packing materials for possible future use.
Refasten top cover on amplifier.
Panel Controls
The front panel has:
1 Power line On-Off switch
1-Power ‘On’ LED (Green) indicator
POWER-ON SWITCH: Initiates/terminates
AC line power to the amplifier. Function
indicated by green LED above switch.
Note: Audio Research does not
recommend leaving your Reference 150
‘on’ 24 hours a day as is the custom of
some audiophiles to achieve maximum
sonic performance on demand. While
this is often recommended for solid-state
equipment, Audio Research does not
recommend this procedure for vacuum
tube power amplifiers. (2,000 hours of
tube life will elapse in 84 days!)
Installation
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 is no restriction
above and behind the unit and on
either side. Be sure that airflow to the
12V D. C. cooling fans located on the
rear panel is not blocked.
The special non-marring elastomer feet
provide adequate spacing and stability
only on a smooth, hard surface. For
upright stability, 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.