- Tip = Signal Phase (“+” or “hot”),
- Ring = Signal Non-Phase (“-” or “cold”).
Unbalanced outputs:
- Screen = Ground,
- Tip = Signal Phase (“+” or “hot”),
- Ring = Ground.
3.5
Nominal Operating Level.
A switch on the rear panel allows the line inputs and outputs to be matched to equipment at
a nominal operating level of +4dBu or -10dBu. Most professional equipment requires
+4dBu (approximately 1.2V rms), but some small mixing consoles, portable tape
recorders or domestic audio equipment require -10dBu (approximately 225mV rms). If
the operating level is not known, the switch should be set to the position which results in the
best signal to noise ratio, whilst preserving sufficient headroom.
3.6
Ventilation.
The FAT 1 generates a small amount of heat internally, mainly due to the valve heater. This
heat should be allowed to dissipate by convection through the top grill, which must not be
obstructed. Do not locate the compressor where it will be subject to external heating, for
example, in the hot air flow from a power amplifier or on a radiator.
The FAT 1 may be free standing (using the self-adhesive feet supplied), or mounted singly or
in pairs in the optional FAT-RACK 3U high 19” rack tray.
4
OPERATION
4.1
What is Compression?
Compression is an essential but often misunderstood process in modern recording. Put
simply, compression reduces the ratio between the loudest and the quietest levels of an audio
signal, which is known as reducing the “dynamic range” of that signal. Before the introduction
of compressors the only way this could be achieved was by “gain riding”, whereby an
engineer would control the fader manually in order to try and anticipate very large levels
(which might distort the signal) or very low levels (which may get lost in noise). The
introduction of compression devices meant that this process could be controlled
automatically, allowing the engineer to get on with more productive jobs!
