Adjustment of the attack and release times allows unobtrusive compression to be applied to
virtually any audio signal, but should very short transients occur the time constants become
signal dependent, generally reduced, to prevent a slow release leaving a ‘hole’ in the signal
after the transient. Also, a fast release setting will be extended by a slow attack setting. This
type of automatic control means that the flexibility of the FAT 1 is greatly extended without
the extra complication of fully variable attack and release controls.
The Attack and Release controls are only active when the Program control is set to Manual
mode. In all of the Preset modes they are disabled and the Attack and Release values are
fixed internally.
4.11
Knee.
The Knee switch enables the FAT 1 to be operated in two different modes - Soft Knee or
Hard Knee. Soft Knee mode offers a gentle compression curve around the threshold point,
and is traditionally employed to yield a more subtle, musical type of compression effect. The
Hard Knee setting causes the full compression ratio to be applied immediately the signal has
passed the threshold point, so tends to produce more pronounced and severe compression.
The Knee control is only active when the Program control is set to Manual mode. In all of
the Preset modes it is disabled and Knee setting is fixed internally.
4.12
Meter.
The FAT 1 is equipped with an illuminated VU meter. The Meter switch enables the FAT
1’s VU meter to monitor one of two parameters. When switched to ‘Output’ the meter
reads the audio output level, and is calibrated to read 0VU for a +4dBu output level. The
reference point may be internally adjusted by your dealer if required. Increasing the Output
Level control on the FAT 1 towards the +20dB setting will cause the FAT 1’s meter to
move further towards the red area and possibly to the end of the scale if sufficient gain is
applied. This is normal, particularly if driving a digital recorder where large input levels are
required.
The meter may be switched to indicate the amount of compression occurring. If the signal is
below the threshold, the meter will indicate 0dB: i.e. no gain reduction. As the signal passes
through the threshold, the meter will start to indicate the gain reduction at the compressor
stage (this will be a
negative
value, so the meter will move to the left, away from 0VU).
Note that this reading won’t include any extra gain make-up applied.
4.13
Compressor On.
This switch enables or disables the compressor stage, thus allowing an A/B comparison to
be made between the original untreated signal and the compressed signal. An associated
status LED indicates when the compressor is active.
