once it has risen above the threshold, while the Release switch controls how quickly the
signal returns to normal once it has dropped back below the threshold level.
The Knee switch controls the shape of the FAT 1 compression curve. In “Soft Knee” mode,
the response curve of the compressor around the threshold is gentle, so that the compression
effect is more subtle and musical. In “Hard Knee” mode, the curve is more severe, so that
signals above the threshold are “squashed” more aggressively. This yields a more audible and
pronounced compression effect.
The Gain Make-Up control is positioned at the output of the compressor stage, and allows
the signal level to be brought back to the same loudness as the uncompressed signal.
4.4
Input Gain.
The Input Gain control sets the level of the signal to the input stage of the compressor and is
variable between -20dB and +20dB. This allows a wide range of signals to be fed into the
FAT 1, and also allows the valve stages to be driven to a variable degree. Each channel of
the FAT 1 has a triode valve stage positioned between the input circuit and the compression
stage. Increasing the input gain pushes more signal level into the valve, thus generating more
harmonic distortion and creating that special “valve sound”. At the same time the output level
can be turned down to preserve the same level at the outputs, so a choice of sounds is
available. For a more pronounced valve sound, turn up the input gain and reduce the output
gain, and vice versa for a cleaner sound. Don’t be afraid to push the FAT 1 hard!
As well as driving the valves harder, increasing the Input Gain control setting will also tend to
push the signal towards and possibly over the compression threshold setting, so this control
will have a pronounced effect on the amount of compression taking place, even in the Preset
modes.
The Input Gain control is active at all times, whether the Program control is set to Manual or
Preset modes.
4.5
Output Gain.
This controls the level at the FAT 1 outputs, and again is variable between -20dB and
+20dB. This control effectively acts like an output fader, and is very useful when recording
direct to tape or hard disc through the FAT 1. You may find that some digital recorders
require a good deal of input level in order to register a 0dB reading on their meters. This is
normal, since many digital recorders are designed to preserve headroom and keep the signal
well below the 0dB clip point - thus preventing the recorder distorting. The FAT 1 provides
ample gain to drive digital recorders, but you may find that the Output Gain control has to be
set to higher levels for this reason (see also section 3.5 on operating level).
The Output Gain control is active at all times, whether the Program control is set to Manual
or Preset modes.
