Audio Research VS115, Owner'S Manual

Page: 5 / 15

Installation
To insure normal component life and safe operation this
unit
must be operated only in a horizontal (upright) posi -
t i o n .
Adequate air flow and proper cooling thereby can
occur only if there is no restriction below, behind and
above the unit.
The four special non-marring elastomer feet provide
adequate spacing only from a smooth, hard surface.
Never
operate the unit while it is sitting on a surface such as
a rug or carpet.
If the unit is to be operated in an enclosed equipment
cabinet, an exhaust fan is desirable so as not to operate the
VS55 in overheated ambient air. 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.
Connections
The rear panel has:
2 – RCA input connectors (for single ended connection,
L & R)
6 – Output binding posts (+) and (-), L & R, for 4 or 8 ohm
speaker connection
1 – Power line cord inlet
1 – Power line fuse holder
2 – 12V remote start in and out jacks
4 – Pairs bias test jacks, one pair for each output tube
IMPORTANT: Use the best available speaker wires and
interconnects. Audio Research cannot emphasize this
enough. As better components and systems are developed,
it becomes increasingly important to avoid the limitations
of inferior system interconnections.
It is important sonically that your entire system be
connected so that the audio signal arriving at the speakers
has correct, or “absolute” polarity (i.e., non-inverted).
Connect the black or “-” speaker terminal to the wire that
connects to the “0” terminal on the VS55. Connect the red
or “+” speaker terminal to the wire that connects to the “4 ”
or “8 ” terminal on the VS55. and tighten the speaker
terminals securely to ensure best sonic results.
MATCHING : It is important to use as close as possible an
impedance match between the amplifier and speaker for
optimum transfer of power to the speaker with minimum
distortion. In the case of speaker systems with significant
variations in impedance throughout the frequency spec-
trum, such as most electrostatic types, determine the best
impedance match empirically for best overall sonic results.
Connect the VS55 input to the preamplifier or electronic
crossover, using only the highest grade of audio intercon-
nect cables. To avoid sonic degradation use the shortest
practical length of cables.
AC POWER CONNECTIONS: It is essential that the VS55
amplifier be connected to a wall AC power receptacle, or
a similar heavy-duty source. If it is connected to conve-
nience receptacles on preamplifiers
,
etc., the full sonic
capabilities of both the VS55 and the preamplifier may be
compromised.
For the very best sonic performance on domestic 100 or
120 volt circuits, the VS55 should be connected to its own
AC power circuit branch, protected by a 15 or 20 amp
breaker. The preamplifier and other audio equipment
should be connected to a different power circuit and break-
er. Avoid the use of extension cords. If they must be used
on a temporary basis, use 14-gauge or heavier cords.
The VS55 utilizes a compatible grounding system that gen-
erally does not require a “ground lifter” adapter plug on the
AC power cord to minimize hum. The power cord on your
VS55 has a standard three-prong grounding plug to provide
maximum safety when it is connected to a ground wall
receptacle. If there is any question regarding the safety
of grounding procedures, be certain to seek competent
help with the installation.
If electronic crossovers or other AC powered equipment is
used with the VS55 it may be necessary to use “ground
lifter” adapters on the power plugs of that equipment to
minimize system hum. Generally, the lowest hum is
achieved when the only direct connection between audio
common “ground” and true earth ground occurs in the
preamplifier, through its grounded power cord. Other
equipment in the system should have some form of isola-
tion to prevent ground loops and associated hum.
Always place the power on-off switch on the panel of
the VS55 in the “O ff ” position before connecting the
power line cord to AC power.
5Model VS115
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VS55 Manual /
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