OTARI RADAR II, Operation Manual, Page: 214 / 261

A.4 ELECTRICAL INSTALLATION
A.4.1 Analog Audio Inputs & Outputs Overview
RADAR II has 24 analog audio inputs and outputs on the rear panel. These
signals are carried on six DB-25 connectors, each of which carries eight channels.
Each connector is bolted directly to the chassis for maximum strength.
A.4.1.1 Balanced vs. Unbalanced Audio Signals
Balanced audio cable has three conductors: two conductors carrying the same signal
at opposite polarities and a ground. Balancing generally results in lower
susceptibility to electromagnetic (EMI) and radio frequency (RFI) induced noise,
and permits longer cable runs without risk of interference. As well, balanced cables
do not necessarily need to be grounded at both ends and this means fewer ground
loop problems.
On the other hand, unbalanced cables have two conductors only: one for signal and
one for return. The return must always be grounded in order for signal to flow. This
scheme is more susceptible to radio or electromagnetic interference and poor quality
cables can be noisy if they are handled. Many studios, however, successfully use
unbalanced lines and you should not have any problems if the audio equipment in
your studio is properly grounded. See the discussion of grounding at the end of this
section.
A.4.1.2 Audio Reference Levels
The Audio Level preference setting provides four level settings for the analog inputs,
and four level settings for the analog outputs. The selections are:
• +24 dBu • +22 dBu • +20 dBu • +18 dBu
These settings refer to scale (or maximum levels). Put another way, these are all +4
dBu operating levels, with +20, +18, +16, and +14 dBu of headroom.
Example: With RADAR II’s input operating level set to +22, a tone of 0 VU coming from a
+4 dBu console will cause RADAR II’s meters to read -18 (dB below full scale).
If the “+24 dBu” input operating level is selected, the RADAR II meter(s) would
show -20 (dB below full scale).
To set or change the system’s default audio level(s), select the Audio Level item from
the Preferences menu.
H A R D W A R E / S O F T W A R E I N S T A L L A T I O N A-7
Edition 1