Many instruments and voices have a very wide dynamic range which needs to be controlled.
A singer, for instance, may be singing quietly one moment and very loudly the next, and
unless compression is applied the vocal won’t “sit” correctly in the mix, in addition to the
problems of distortion on loud passages and noise on quiet ones. Thus with compression you
are effectively turning down the loud bits and turning up the quiet bits, to achieve a more
even and controllable level.
But there are other benefits of compression as well - applied properly, it can add punch and
excitement to music, as well as fattening up sounds and creating a more professional
sounding recording. With the FAT 1, you have the added benefit of valve stages in the signal
path, which create a warmth and presence just not obtainable with solid state or digital
products.
4.2
Why Valve Compression?
Valve compression yields a particularly special sound which has become very sought after,
particularly with the widespread use of digital products. The reason valve equipment sounds
special is due to two things: harmonic distortion and natural compression. When the signal
through a valve is increased, it tends to generate a particular type of subtle and desirable
distortion, called “second harmonic” distortion. This has the effect of thickening and warming
the sound, and the more the level you feed to the valve stages, the more of this harmonic
distortion will be produced. You should be able to hear this effect as you increase the Input
Gain on the FAT 1.
Secondly, valves will tend to naturally compress an audio signal, again particularly as the
signal level is increased. This itself also contributes to the warmth produced by the FAT 1.
4.3
Overview of Compressor Operation.
The FAT 1 offers two distinct ways of working: manual or preset modes. In manual mode,
all the compressor controls are active and adjustable, so that compression settings can be
created from scratch to suit the user’s taste. In the fifteen preset modes, the Threshold,
Ratio, Attack, Release and Knee controls are disabled and each is fixed internally at a value
that is selected to give the best results with that particular instrument (the presets are titled
‘vocal’, ‘bass’, ‘guitar’, ‘snare’ etc. to indicate the recommended application).
The FAT 1 functions by reducing the gain of the signal when it rises above a certain level,
known as the Threshold. Any signal below the threshold passes through the unit unaffected.
Above the threshold the gain of the signal is reduced, and the degree of gain reduction is
determined by the Ratio control. The Ratio control is calibrated in dBs and is simply the
change in output level that results from a given change in input level.
The Attack and Release switches are used to control how fast the compressor reacts to the
audio signal. The Attack switch governs how quickly the FAT 1 acts to compress the signal
