Operating Procedure - Audio Research Reference 610T Owner's Manual

Model Reference 610T
In the event of A. C. interruption or low-A. C. line condi-
tions while in "Operate", the amplifier automatically mutes
the output without indication in the display. When
sufficient A.C. supply resumes, the amplifier will enter its
normal two-minute warm-up cycle.
Handheld Remote Control Functions
All display functions of the Reference 610T may be
addressed by pressing buttons on the handheld remote
control. Note that power on/off, Standby and Operate
modes can only be selected by using the front-panel rotary
control.
INTENSITY: Adjusts level of display screen illumination to
any of seven levels including full off.
H O U R S : Displays accumulated hours of vacuum-tube
service life, up to 500,000 hours. If the amplifier is
unplugged from A.C. supply, total accumulated hours are
retained. May be reset by qualified technician. Contact
Audio Research Customer Service for more information
about reset procedure.
POWER SCALE DOWN/UP: Selects and displays power
output scale via moving logarithmic bar graph: 0-10 watts,
0-30 watts, 0-100 watts, 0-300 watts, 0-600 watts. The nor-
mal default display mode when the amplifier is in Operate.
READ BIAS V1–V16 DOWN/UP: Displays bias level of each
output tube in mA. When selected, V1 or V2 may also be
adjusted by inserting the supplied flat-bladed tool into the
respective adjustment pot on the front panel and rotating
until "65 mA" appears in the display. All other tube loca-
tions (V3–V16) may only be checked for bias level, not
adjusted. They should normally display a bias value
between 57 and 73 mA. Note that amplifier is muted in
this mode.
DISPLAY FUNCTION DOWN/UP: Selects desired display
function from options listed above, also including
display of A.C. line voltage entering the amplifier, shown in
large numerals. Amplifier is muted when checking line
voltage.
Connections
INPUT CONNECTOR: The Reference 610T uses a fully bal-
anced circuit topology and thus has one balanced XLR in-
put connector on the rear panel. It therefore requires a
balanced preamplifier output, as provided by most Audio
Research preamplifiers. Connect your preamplifier's output
to the Reference 610T before turning on the amplifier.
OUTPUT CONNECTORS: Proprietary, heavy-duty output
terminals are provided on the rear panel for 4, 8,or 16-ohm
speaker impedance loads. Using high-quality speaker
cables, securely fasten the (-) speaker lead to the appropri-
ate (-) terminal, then the (+) lead to the matching (+) termi-
nal. following your speaker manufacturer's impedance spec-
ification. The Reference 610T puts out the same amount of
power whether the 4, 8 or 16-ohm terminals are used.
A.C. POWER CONNECTIONS: It is important that the
Reference 610T be connected via its supplied 20 amp IEC
12-gauge power cord to a secure, dedicated A.C. power
receptacle. Never connect to convenience power receptacles
on other equipment. Only use the power switch on the
front of the Reference 610T for On/Off control of the ampli-
fier. Note that there is not a 12V start-up trigger for remote
installations.
The A. C. power source for the Reference 610T should be
capable of supplying 20 amperes for 120V units, or 10
amperes for 220/240V units. Preferably, the amplifier
should be connected to its own A. C. power circuit branch,
protected by a 20-30 amp circuit breaker. The preamplifier
and other related equipment should be connected to a
separate power circuit and breaker. If the power receptacle
is more than 25 feet from the building's power entrance
and breaker box, circuit wiring capable of 30 amperes
should be installed to minimize voltage drop using a
20-amp breaker. Avoid the use of extension cords. If they
must be used on a temporary basis, use 12-gauge cords
or heavier.
The Reference 610T should be turned on a f t e r the other
components of your system. If the Reference 610T
is turned on before other components, the amplifier will
amplify any extraneous turn-on noises those components
might generate, which could potentially damage the loud-
speakers. Good operating practice dictates that the ampli-
fier should be turned on last, and turned off first in an
audio system.
The Reference 610T uses a grounding system that does not
require a ground-lifter adaptor plug on the A. C. power cord
to minimize hum. The power cord supplied with the
Reference 610T has a standard grounding plug to provide
maximum safety when properly connected to a grounded
wall receptacle. If there is any question regarding proper
grounding procedures in your installation, seek help from a
qualified technician. Caution should be taken before using
custom after-market power cords: they must be at least
12-gauge and have a standard grounding plug properly
installed. These power cords are to be used with caution, at
the sole risk of the owner.

Operating Procedure

Start-Up:
1. Secure input connection between the amplifier and your
preamplifier; attach speaker leads to the appropriate
output terminals.
3