Owner`s manual

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 210
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 neces-
sary. 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 pro-
tect 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 6N1P input
tube, two 6550C drivers, and 6-6550C output tubes. In
addition, two power-supply regulator tubes–one 6N1P
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 recommend-
ed 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 discre-
tion 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 air flow 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. F o r
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 air flow above
and to each side of the unit is provided. The “ambient”
operating temperature should never exceed 120º F or 49º 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.
Warnings
1. To prevent fire or shock hazard, do not expose this
product to rain or moisture.
2. This unit operates on voltages which can cause serious
injury or death. Do not operate with cover removed.
Any necessary servicing should be carried out by your
authorized Audio Research dealer or other qualified
Model Reference 210
2