Vision manual page:30
the system clean.
Connect stereo tape recorders (inputs and outputs), stereo headphone amp, and all signal processors.
NOTE:
MAKE SURE THAT YOU CHECK FOR HUM OR NOISE AS EACH INPUT OR OUTPUT IS CONNECTED.
10.4 Shields & Group Equipment
The shield of any audio cable connection should be connected at one end only. If not, ground loops and high
frequency cross-talk could result. Connect the shield as a general rule to the signal source (output) of anything. In
high RF areas it is wise to ground the other end of the shield through a 0.01 microFarad capacitor. This will ground the
RF but will not affect audio frequencies.
10.5 Typical Interface Situation Table
Output
Input
Connect
shield
at:
Unbalanced Unbalanced Output
Unbalanced Balanced
Output
Unbalanced Differential Output
Balanced
Unbalanced
Input
Balanced
Balanced
Output
Balanced
Differential
Input
Differential Unbalanced
Output
Differential Balanced
Output
Differential Differential Output
Use the above table to interface your Vision to any external equipment such as multi-track machines, signal processing,
and power amps. Balanced (in the above illustration) means transformer balanced while differential means
electronically balanced. There are some cases which net better results in practice. Connect one circuit at a time and
check for hum or noise. When connecting balanced microphones, use two conductor shielded audio cable and connect
both conductors and the shield at both ends.
When connecting line level cables, use two conductor shielded cable and follow the instructions in the interface table.
The only exception to these rules is with patch cords. These grounds are tied together in
the console. We realize that the correct interfacing of all different equipment is difficult, but once properly installed the
system will be clean and noise free.
It is important to understand the term balanced. Balanced does not mean the input or output is professional, the single
factor that normally determines whether something is professional is the level of the input or the output. +4 dBu is
considered professional. -10 dBv is considered semi-professional. Because many semi-professional tape machines are
built to professional specifications, D&R builds into the Vision console the ability to interface with both levels.
