Audio Research Reference 75, Руководство пользователя

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The Reference 75 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 75 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.
If electronic crossovers or other AC
powered equipment is used with the
Reference 75 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 isolation to prevent ground
loops and associated hum.
Always place the power on-off switch on
the panel of the Reference 75 in the ‘Off’
position before connecting the power line
cord to AC power.
Remote Turn-On Connections
The Reference 75 has a built-in 12VDC
remote turn-on/off circuit for operation by
a master control system in a home theater
or large audio system. Use a 3.5mm (.140")
diameter mono mini plug to connect to
the +12V IN jack on the rear of the
Reference 75. Two identical paralleled
jacks are provided to allow chaining
connections to control two or more
Reference 75s or other equipment.
The +12V IN jack should be connected to
the +12VDC output of the master control
system, using a continuous +12VDC signal
at 12mA per Reference 75 for the duration
of amplifier on-time. Do not use a
momentary or data pulse control signal.
The front power rocker switch on the
Reference 75 must be off to use the
remote turn-on. The front power rocker
switch may still be used when the remote
turn-on is connected, but the remote will
not turn the Reference 75 off if the front
power rocker switch is left on. The front
power rocker switch will not turn the
Reference 75 off if the remote system is on.
The +12VDC remote jacks have polarity
protection, so they will not operate if a -
12VDC signal is accidentally connected,
or if the control wires are reversed.
The 12V remote relay in the Reference 75
has click suppression to protect circuits in
the master control system.
Operating Procedure
Start-Up
1. Secure input connection between the
amplifier and your preamplifier; attach
speaker leads to the appropriate output
terminals.
2. Attach supplied power cord to rear IEC
inlet of amplifier, and plug other end into
grounded A.C. power receptacle.
3. Turn on preamp and all other
components; mute preamp output.
4. Turn Reference 75 front-panel power
switch from Off to On. Green power LED
will light.
5. Unmute preamplifier output, initiate
source component signal, and adjust
gain as appropriate.
Shut-Down:
1. Mute preamplifier output.
2. Turn Reference 75 front-panel control
from Operate to Off. Green power LED
will stop glowing.
3. Turn off preamplifier and then the
associated input source components.
Note
After the Reference 75 is
turned off, wait at least five
minutes before turning it on
again.