Adcom THX GFA-7000 - Manual (Page 11)

CONNECTING THE GFA-7000
Remember, that the Left and Right designations are as you are sitting down in your
listening/viewing area. On the rear panel, the inputs and outputs are grouped in 5 bracketed
sets, one for each channel. They are abbreviated as indicated;
RR....................................... Right Rear
LR.......................................... Left Rear
R.................................................. Right
C................................................ Center
L..................................................... Left
Oinputs:
To preserve the correct effects, be certain to connect the RCA cables to the proper RCA-
input connector. If the cables are color coded, then use this sequence for the connections:
Blue..........................................................Left(L)
Red....................................................... Right(R)
Green..................................................Center(C)
White with Blue Stripe.................................Left Rear(LR)
White with Red Stripe...............................Right Rear(RR)
Home THX® certified RCA cables will have directional arrows printed on the side of each
cable. Make certain that these arrows are pointed towards the GFA-7000. The recommended
maximum RCA cable capacitance should be less than or equal to 30pF per foot when
measured between the two conductors, and less than or equal to 50pF per foot when measured
between one conductor and the shield.
With the DB-25 computer-type Multichannel input connector(O), there is no need to worry
about color coding or properly connecting the RCA plugs, as this is done in One connector with
one cable. The DB-25 can easily transfer all five channels from the output of the Home THX®
processor unit to the input of the GFA-7000 amplifier. There can be no errors with the DB-25, it
is shaped so that it can only be connected in the proper direction. Contact your dealer to locate
a THX® DB-25 signal cable.
OOutputs:
NOTE:
The GFA-7000 is “polarity correct”. That is it does not invert phase from input to output. Any
positive signals at its inputs will appear as a positive signal at its outputs
In connecting the amplifier to the loudspeaker, it is vital to maintain proper polarity (positive
to positive, negative to negative). On the GFA-7000, 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”.
It is recommended by the Home THX® standards 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”
(see diagram on right).
max 0 57” 0 25" min
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