FXPANSION BFD2, Руководство пользователя

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Comp Chan
The CompChan (channel compressor) is derived from a classic ‘feedback-based FET limit-
ing amplifier’ design.
It is also what is known as a ‘fixed-threshold’ design – the threshold at which compression
starts is not adjustable. In practice, this means you may need to adjust the input and output
levels when changing ratios.
Input & Output
This control varies the input level going into the compressor. Once the input level has
reached the internal threshold, compression begins. When this happens, use the Output
control to turn down the increased input. The Input control ranges from -20 tp +40 dB, while
the Output control ranges from -40 dB to +20 dB.
Attack
The Attack control has a an arbitrary range of 0 to 10, which equates to a real-world range between 0.02 ms and 0.8 ms.
Release
The Release control has a an arbitrary range of 0 to 10, which equates to a range between 50ms and 1.1 seconds.
Ratio
Ratios available are 4:1 , 8:1 , 12:1, 20:1 and ‘Nuke’, which is an emulation of the ‘all buttons in’ mode on a classic limiting ampli-
fier design. It results in a particularly brutal type of compression.
Comp Bus
This compressor is based on a classic bus compressor design from the centre section of a
well-known British large-format mixing console.
It is most commonly used to add ‘glue’ and power to a drum bus. However, it also works very
well as a channel compressor in its own right, offering a different flavour of compression
compared to the Comp Chan.
Attack
Six attack times are available: 0.1 ms, 0.3 ms, 1 ms, 3 ms, 10 ms, 30 ms.
Release
Five release settings are available: 0.1 ms, 0.3 ms, 0.6 ms, 1.2 ms and Auto.
Ratio
Three ratio settings are available: 2:1, 4:1 and 10:1.
Threshold
Unlike the channel compressor, the buss compressor allows you to adjust the threshold, which represents the input level at which
the compressor starts to react.
Make up gain
This control allows you to increase the output gain after the compressor circuit has applied gain reduction to the input signal.
Analog limit
This button applies analog non-linearities to the input to the compressor’s amplitude detection circuit (while not affecting the input
signal itself). This results in a different character to the processing – the compression effect is more transparent on attacks.