Adcom GFP-345 - Manual (Page 6)

To connect the processor, equalizer or surround-sound decoder, etc., to the GFP-345 always use high-quality low-loss
audio cables. Plug the jacks on the signal processor labelled "input", "in”, "line-in", or “source” into the EXTERNAL
PROCESSOR OUT
O
jacks on the rear panel of the GFP-345, observing the left and right labelling on both sets of jacks.
Plug the jacks on the signal processor marked “output, “out" or "line-out" to the GFP-345 jacks labelled EXTERNAL
PROCESSOR IN ©. Once these connections have been effected simply pushing In the EXT PROC © button on the front
panel of the GFP-345 will bring the processor info the circuit.
NOTE
1. Please be advised that if no processor is plugged into the EXTERNAL PROCESSOR IN O and EXTERNAL
PROCESSOR OUT O jacks, and the EXT PROC ® button is pushed in, all the inputs of the GFP-345 will be
disconnected and no output signal will be present at either the OUTPUTS NORM ® or the OUTPUTS LAB
o and, consequently, no sound will be heard through the system. Whenever a signal processor is not being
used, the EXT PROC ® button should always be in the out position.
2. However, it is possible when no processor is connected to the EXTERNAL PROCESSOR IN O and
EXTERNAL PROCESSOR OUT O jacks, to use the EXT PROC ® button as a mute function. By pressing In the
EXT PROC 0 button the signal will be interrupted until the EXT PROC ® button is, once again, pushed in and
released.
3. Normally, the GFP-345 does not invert polarity; that is, if a positive-going signal is present at any of its inputs,
it will appear as a positive-going signal at the outputs. However, if a signal processor is connected to the
EXTERNAL PROCESSOR IN O and EXTERNAL PROCESSOR OUT O jacks, and its circuitry inverts polarity,
the signals present at the OUTPUTS NORM © and OUTPUTS LAB O will also be inverted in polarity (check
the Instruction Manual of your signal processor to determine if it does or does not invert polarity).
4. Usually, there should be no appreciable level difference whenever a signal processor is connected into or out
of the circuitry of the GFP-345 (through the use of the EXT PROC 0 button), so long as the processor was
designed with an absolute gain of 1 and adequate input and output impedances to fulfill this function. If a level
difference can be detected when switching a processor in and out of the circuit, and this is disturbing to you,
please contact the manufacturer of the processor you are using to see if a correction of this level difference cari
be effected.
5. It is also possible to employ the EXTERNAL PROCESSOR IN О jacks as an additional set of Inputs, since
these jacks are located, in the circuitry, before the LEVEL
0
and BALANCE
0
controls. If you wish to use the
EXTERNAL PROCESSOR IN О jacks as an additional input, simply plug the signal source into the EXTERNAL
PROCESSOR IN О jacks as wu would any of the other inputs (CD O, TUNER O. etc.) and select that source
^ pushing In the EXT PROC
0
button. Whatever other selection of sources has been made through the INPUT
0 selector will bedisconnected and the source plugged into the EXTERNAL PROCESSOR IN О jacks will then
be fed through the circuits of the GFP-345 and out of the OUTPUTS NORM ©.and OUTPUTS LAB ©