Panel Controls; Use Of Controls; Installation; Connections - Audio Research VS115 Owner's Manual

Model VS115
ten on the base of the tube) to the "V" number printed next
to each socket. Firmly seat each tube in its matching sock-
et, taking care to "key" the tube pins to the socket holes.
Retain the foam blocks with other packing materials for
possible future use.
2. If you are using the optional tube cover, be sure the
VS115 is first turned off and then remove the top plate
with the phillips screwdriver provided with the tube cov-
er. Install the tube cover in place of the top plate, using
the new screws supplied.

Panel Controls

The front panel has:
1 – Switch: 1 - Power line On-Off
1 – Indicator: 1 - Power "On" LED (Green)

Use of Controls

POWER-ON SWITCH: Initiates/terminates AC line power
to the amplifier. Function indicated by green LED above
switch.
N o t e : Audio Research does n o t recommend leaving your
VS115 "on" 24 hours a day as is the custom of some audio-
philes 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
pass by in 84 days!)

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 five 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
VS115 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,
2
conservative levels and will not be improperly affected
thereby, providing the requirements outlined above are
adhered to.

Connections

The rear panel has:
2 – BAL input connectors (for balanced connection, L & R).
2 – RCA input connectors (for single ended connection,
L & R) See Single Ended Operation and Balanced
Operation paragraphs for instructions on use of
jumpers for SE operation.
2 – Jumper sockets for single ended operation, L & R.
6 – Output binding posts (+) and (-), L & R, for 4 or 8 ohm
speaker connection.
1 – Power line cord 20A IEC inlet connector for removable
power cord (supplied).
1 – Power line fuse holder.
2 – 12V remote start in and out jacks.
8 – 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 VS115. Connect the red
or "+" speaker terminal to the wire that connects to the "4 "
or "8" terminal on the VS115. 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 VS115 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 VS115
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
capabilities of both the VS115 and the preamplifier may be
compromised.
,
etc., the full sonic