11
CONNECTING THE GFA-7805/7807 TO YOUR SPEAKERS
When connecting the amplier to the loudspeaker, it is vital to maintain proper polarity (positive to positive, negative
to negative). On the GFA-7805/7807, the positive terminal is color coded RED and labeled “+,” and the negative is color
coded BLACK and labeled “-”. The positive terminal on the speaker will be color coded RED, or will be labeled “+,” “pos,”
“positive,” “8 ohms” or “4 ohms.” The negative terminal on the speaker will be color coded BLACK, or will be labeled “-,”
“neg,” “negative,” “C,” “Common,” “G,” or “ground.”
We recommend that your speaker cables be terminated with “U” type spade connectors. These will give the most contact
area insuring long-term reliability. The spade connector should have a maximum width of 0.57 inches and an opening
width of no less than 0.25".
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 rmly secured. Finger pressure is sufcient and you should not use pliers or other tools which could
damage or over-tighten the binding-post assembly. The binding posts have been designed in such a way that nger 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 avoid unnecessary loss of amplier power in the cable,
reduction of amplier damping factor and other undesirable conditions. Sound audio engineering practice suggests the
use of at least AWG16, stranded, copper cable. Recommended capacitance of the speaker wire should not exceed 5OpF
per foot. This insures high frequencies will not be rolled off.
All loudspeakers having a nominal impedance down to 4 ohms can be connected to and driven by the GFA-7805/7807.
The amplier can drive these low-impedance speakers at more than adequate power levels with no difculty. It should
be noted 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 difculties even with these very low
impedance loads unless you demand excessively high volumes levels from your system.
We do not recommend that you run additional sets of speakers to the GFA-7805/7807. If you choose to add remote
speakers in another room, we strongly suggest 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 or GFS-6
speaker selector is recommended. A Speaker Selector enables you to maintain good sonic integrity while giving you the
exibility to add speakers throughout your house.
We suggest that you follow this chart below for maximum speaker lengths and minimum wire gauges. If longer runs are
needed, we recomend that you consult with your ADCOM Dealer to maximize the performance of your system for your
exact conditions.
up to 24 feet AWGI6 up to 36 feet AWGI4 up to 58 feet AWGI2
