Adcom GFA-555MS - Manual (Page 6)

packed with the optional rack-mount adaptors for more information.
CONNECTING THE GFA-555ms
The optimal performance of the GFA-555ms will ultimately depend on the care with which
you perform the connections to the amplifier, the preamplifier and the loudspeakers. All the
input- and output-signal connections should be made only with high-quality, low-loss cables
following the recommendations made in the individual sections below. Please refer to the
rear-panel diagram to identify all the connections and their locations.
NOTE
WHENEVER CONNECTIONS TO OR FROM THE GFA-555ms ARE BEING MADE, BE
CERTAIN THAT THE POWER SWITCH ON THE AMPLIFIER IS IN ITS OFF POSITION,
THE AC LINE CORD OF THE AMPLIFIER IS DISCONNECTED FROM THE AC WALL
OUTLET AND THAT ALL ASSOCIATED COMPONENTS ARE TURNED OFF.
RIGHT/LEFT INPUT
The audio inputs to the GFA-555ms are through two high-quality, gold-plated brass RCA
jacks using Teflon insulation to minimize high-frequency losses, noise, etc. They will accept
standard RCA-type plugs, one for each channel, LEFT and RIGHT, usually supplied at the
ends of interconnecting cables. To insure that the performance designed into the
GFA-555ms is preserved, you should use the highest quality plugs and cable as are feasible.
There are many cables which are designed specifically for these applications and your
ADCOM dealer can be of help in selecting the best cable for your application. Whatever
cable you finally select, it should have low capacitance. This is particularly important if you
use a long run between the preamplifier and the amplifier or if your preamplifier has a high
output impedance. Generally speaking, a cable with a capacitance of around 100pF will
work well.
The load impedance which the GFA-555ms inputs present to the source preamplifier is
100,000 ohms. This load impedance results in minimal amplifier noise and is more than
adequate for use with any associated source component regardless of its output impedance.
To preserve the correct stereophonic effects, please be certain to connect the left output of
the preamplifier to the RCA jack on the GFA-555ms labeled LEFT INPUT and the right
output of the preamplifier section to the RCA jack labeled RIGHT INPUT.
RIGHT/LEFT STEREEO SPEAKER OUTPUTS
The GFA-555ms's connections to the loudspeakers are made through high-grade 5-way,
gold-plated brass binding-post terminals located on the rear panel. These terminals will