Adcom THX GFA-7000 - Manual (Page 12)

To properly connect the speaker cable to the binding posts, turn the insulated head of the
binding post clockwise until the wire or connector is firmly secured. Finger pressure is sufficient
and you should not use pliers or other tools which could damage or over-tiqhten the binding-
post assembly. The binding posts, haye been designed in such a way that finger pressure is all
that is required to cause a “pinching” action among the different metal surfaces to ensure
proper connection.
It is very important to use the correct size of wire in order to ayoid unnecessary loss of
amplifier power in the cable, reduction of amplifier damping factor and other undesirable
conditions. Home THX® specifications require the use of at least AWG16, stranded, copper
cable. Recommended capacitance of the speaker wire should not exceed 50pF per foot. This
insures high frequencies will not be rolled-off.
It is suggested that the three front channels follow this chart for speaker lengths and wire
gauges. These recommendations are standardized Home THX® performance specifications.
up to 24 feet......................................... AWG16
up to 36 feet......................................... AWG14
up to 58 feet......................................... AWG12
Generally, for the two rear surround channels, longer runs of cable are needed, but since
less program material is being transmitted through the cable, longer runs are acceptable:
up to 48 feet......................................... AWG16
up to 72 feet......................................... AWG14
up to 116 feet......................................... AWG12
If longer runs are needed, it is best to consult with your Adcom Dealer to maximize the
performance of your system with your exact conditions.
All loudspeakers haying a nominal impedance down to 4 ohms can be connected to and
driven by the GFA-7000. The amplifier can drive these low-impedance speakers at more than
adequate power levels with no difficulty. It should be noted here that many loudspeaker
systems which are nominally rated at 4 ohms drop in impedance, in some parts of their
frequency range, to as low as 2 ohms (and sometimes less). You will not experience difficulties
even with these very low impedance loads unless you demand excessively high volumes levels
from your system.
It is not recommended that you run additional sets of speakers on any or all of the
amplifiers in the GFA-7000 in order to insure the integrity of a Home THX® system. If you
choose to add remote speakers in another room, it is strongly suggested that a switching
system to disconnect the non-home-theater speakers be incorporated when the surround
sound, home-theater mode is in operation. A device such as the Adcom GFS-3, GFS-4 or
GFS-6 Speaker Selector is strongly recommended. A Speaker Selector enables you to maintain
Home THX® integrity while giving you the flexibility to add speakers throughout your house.
CARING FOR YOUR GFA-7000
Great care has been taken by ADCOM to ensure that your amplifier is as flawless in
appearance as it is electronically. The front panel is a heavy-gauge, high-grade aluminum
extrusion carefully finished and anodized for durability. The chassis, top cover and rear panel
are heavy-gauge steel that has been powder coated and baked to ensure a lasting finish. If the
front panel, top or sides become dusty or fingerprinted, they can be cleaned with a soft lint-free
cloth, slightly dampened with a very mild detergent solution or glass cleaner. DO NOT SPRAY
OR POUR LIQUIDS OF ANY KIND ON THE GFA-7000.
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