Audio Research Reference 250, Руководство пользователя

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Preface
Please take time to carefully read and
understand the following information and
instructions before you install or attempt to
operate your Audio Research Reference
250 vacuum tube monoblock power
amplifier. Becoming familiar with important
facts about your amplifier and its correct
operating procedures will help assure
maximum musical satisfaction and reliable
operation.
Packaging
Save all packaging accompanying this
product. You have purchased a precision
electronic instrument, and it should be
properly cartoned any time shipment
becomes necessary.
It is very possible that this unit could be
damaged during shipment if repackaged in
cartoning other than that designed for it.
The original packaging materials help
protect your investment from unnecessary
damage, delay and added expense
whenever shipment of this unit is required.
Accessories
1 – Phillips-head screwdriver for panel
removal.
1 – Plastic screwdriver for front panel
potentiometer bias adjustment.
Fuses
1 – 2 Amp MDQ slo-blo for LV power
transformer in
120V units.
1 – T1 Amp fast-blo for LV power transformer
in 220,
240V units.
1 – 4 Amp MDQ slo-blo for start-up circuit in
120V units.
1 – T3.15 Amp fast-blo for start-up circuit in
220, 240V units
1 – 7 Amp MDX for main power in 120V units.
1 – T4 Amp fast-blo for main power in 220,
240V units.
Vacuum Tubes and Preparation
for Use
Do not attempt to operate this amplifier
before installing the necessary vacuum
tubes in their indicated sockets. The tubes
are protectively packed in a separate
carton; save packing for possible future use.
1. All input, driver and output-stage tube
locations are clearly labeled with tube type
and “V” number on one circuit board of the
amplifier. There is one 6H30 input tube, two
KT120 drivers, and 6 KT120 output tubes. In
addition, two power-supply regulator tubes
– one 6H30 and one 6550C – are located on
the second circuit board on the other side
of the amplifier.
2. Match each tube's “V” number marked
on the tube with the “V” number of the
corresponding socket. Insert tubes by
carefully aligning tube pins with socket holes
and gently applying downward pressure.
The base of the tube should firmly contact
the surface of the socket.
3.
Note: In general, contact enhancers are
not recommended for use on vacuum tube
contact pins. With continual exposure to
heat and air, many of these substances can
form gummy, dust-collecting residues which
actually reduce contact and degrade sonic
performance. Proper external use of these
preparations – on interconnect plugs,
speaker connections, etc.– is subject to the
discretion of the owner. Contact Audio
Research for specific recommendations.
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 fan 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.