Lexicon NT Series Amplifiers 312 - Manual (Page 10)

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Lexicon NT Series Amplifiers
Lexicon amplifiers do not require any specialized line conditioners, as they have
special power supply circuitry designed to reject power line problems like line
spikes, surges and RFI. Simply plug each amplifier directly into a line socket. In
areas where there is a high likelihood of lightning strikes or other potentially
catastrophic surges, additional protection may be warranted. Verify that any
surge protection device you choose has ample power conducting capabilities.
High power installations may benefit from a review of your electrical service to
ensure that adequate power is available and to minimize the chance of ground
loops.
Amplifiers rated for 120V may be used only on a 60Hz line.
Complete all audio input and output connections and make sure that the front
panel power switch is in the OFF (out) position before connecting the AC power
cord.
Power
Requirements
Audio
Connections Never make or break any connection unless power to the amplifier has been
disconnected. Unless you are bridging channels, make sure the mode switch
adjacent to the input is set to individual.
Gain level is automatically matched to the type of input used when you select
the unbalanced (RCA type connectors) or balanced mode (XLR or 1/4") with the
rear panel switch.
Use high quality speaker cables of at least 16 gauge. For runs longer than 3
meters, thicker (lower AWG#) cable should be used. The total loop resistance
of the speaker wire should be less than 0.1
Ω . Consult your dealer for specific
recommendations.
All input and output connectors are gold plated and should be used with high
quality cable with gold plated connectors for optimal low-distortion and
reliable signal transfer.
One of the biggest challenges in large audio and video systems is minimizing
the audio hum caused by a “ground loop”. Raising the amplifier rear panel
Ground Lift switch to its up position puts a 10
Ω resistor in series between the
system ground and the chassis ground. The chassis is still grounded.
This may reduce the hum. Do NOT leave the ground lifted if it does not make
a difference.
Often hum is caused in A/V systems through connection to cable TV cables or
other equipment which are at a different ground potential. Addressing this at
the source is the most efficient path to a clearer, quieter system.
Ground Lift Switch
The Ground Lift Switch does not
disconnect the chassis from the third
prong on the power cord which must
be left intact for safety reasons.