SPL Iron V2 Two-Channel Tube Mastering Compressor (Black/Silver) - Manual (Page 17)

17
Control Elements
Release
The counterpart of the Attack is Release. The Release parameter determines how fast the
compressor eases processing the signal. To be precise, it determines the time in which
63% of the reduced gain is restored. Similarly to the Attack time, the Release time can
also be set in six steps from Fast to Slow. Likewise, exact Release time settings are not
possible. Once again, there are no constant values, since the Release time depends on
the rest of the parameters, too.
Although the Attack and Release times can be considered fixed intervals, the control-time
behavior and operating mode of the tubes is very different depending on the music. That
is why these values should not be considered absolute values.
On page 23 you will find an overview for orientation, which shows the time values
depending on the chosen rectifiers.
Tip: Compression during vocal recordings
The attack time should not be too fast, otherwise plosives could be distorted, resulting in
the vocals sounding unnatural. Many sound engineers compensate these level variations
by automating the fader. The actual peaks of vocals are not at the beginning of a syllable,
but rather later, when long vocals come along, which ought to be limited as well. That is
why the Attack time should be relatively slow and the Release time relatively fast.
Rectifier
To produce the bias voltage to control the parallel connected tubes we use a rectifier.
This circuit has six different operating characteristics (different rectifiers), which can be
selected with the corresponding switch. They have a direct impact on the Attack and
Release times.
In comparison to the other rectifiers, the rectifier circuit LED delivers the longest/slowest
time values. You can find more information at the time values overview on page 23.