
CH PTER 2 Installation and wiring
2.1 Overview
Installation of Solidyne D-612 doesn’t present partic-
ular jobs. However, keep in mind the basic rules for
all professional audio installations. The balanced in-
puts of the D-612 uses DIN-5 multipin connectors
(provided with the console). In option, you can ac-
quire the Solidyne wiring kit (MNG612), which inl-
cude all the cables and connectors needed for the
set up.
For console grounding use the rear side GND
bronze tip with a mm cable to a good buried
cooper bar.
2.1.1 Parasitic signals
ll unwanted signals that appear in audio lines usu-
ally consider parasitic signals. common type are
denominated humming, low frequency signals (mul-
tiples of 50/60 Hertz) caused by the interaction of
electromagnetic fields coming from the C line.
When the interference source is a magnetic field
(generally originated in a supply transformer) the
resultant interference will be denominated electro-
magnetic humming. When the interference is due to
such electric potentials as cables that take supply
tensions, that are elevated in comparison with the
audio signals present in the circuit, you will be in
presence of electrostatic humming. The distinction
is not merely academic, because the resolution of a
problem supposes the knowledge of the noise type
to apply the correct solution.
Examples: To minimize the reception of electromagnetic
humming in the wires, remember the following rule: "THE
AREA AMONG TWO AUDIO WIRES WILL BE MINI-
MUM." It implies that the cables will be tied very close,
like the shielded twisted pair audio cables. They should
pass far away from any transformer or devices that man-
age high-intensity currents. Is important to remember that
a wire can be good shielded, but if his conductors don’t
complete the conditions of minimum area it will be sus-
ceptible to take magnetic humming.
Other parasitic signals are: C HUM, R DIO FRE-
QUENCY and CROSST LK. s hum noises like
the radio frequency are originated by electromag-
netic fields of high frequency; the first ones are orig-
inated by disturbances due to the connection and
disconnection of equipment’s to the C line, the
seconds ones are generated by communications
transmitters or industrial equipment. If these signals
penetrate into audio lines, with sufficient intensity,
can surpass the action of the special protection fil-
ters, and to reach some sensible part of the input
stages. In that case, the interfering signals can be
demodulated and already turned audio signal, and
will be amplified by the rest of the system. It is fun-
damental, therefore, to maintain the interference
within reduced margins. It is obtained avoiding very
long audio lines, with aerial sections or that pass
near of transformers or RF transmitters. For protec-
tion against very high frequencies is advisable to
use double shielded cables, guarantied by the man-
ufacturer.
CROSST LK is the reception of signals coming
from other lines of audio. This, like all unwanted
noise, it can be supposed controlled when its level
is below the level of the system residual noise.
Then, all considerations mentioned for the case of
buzz are valid.
2.1.2 RF interference (Hum)
D-612 consoles have numerous internal protections
against RF fields, for the M and FM broadcasting
band. When the transmission station is installed
correctly, there will be no interference problems,
still with FM equipment of 50 KW installed in the
terrace of the radio station. Nevertheless, when the
antenna is badly positioned with respect to the Stu-
dio or has severe SWR problems, then it does not
have the minimum value of field intensity, down-
ward. Or maybe there is a faulty ground connection,
then, strong standing waves will appear on the ca-
bles of the Studio that can induce high electrical
currents inside the audio console.
Symptoms: If the interference takes place at the
.M. band, the sound transmitted by the .M. radio
will be listened in the loudspeakers on background
(or at buses PGM, REC). In case of FM transmis-
sions, the interference inside the console demodu-
lates the .M component of the FM carrier; (usually
hum from power supply) causing background hum-
ming, because in many transmitters of FM, the final
output stage is not powered with stabilized tension.
Therefore, if console D-612 presents humming,
please make a test shutting down the transmitter a
few seconds to check if the problem disappears.
Sometimes, an FM transmitter with the output stage
badly calibrated also produce interference in which
you can hear the transmitted audio (due to the mis-
alignment a part of the FM modulation is translated
to M modulation).
Page 7 www.SolidynePro.com