E-MU 0404 PCI - Manual (Page 57)

5 - Effects
Core Effects Descriptions
E-MU Digital Audio System 49
Chorus
An audio delay in the range of 15-20 milliseconds is too short to be an echo, but is
perceived by the ear as a distinctly separate sound. If we now cyclically vary the delay
time in this range, the illusion of multiple sound sources is created. A slight amount of
feedback serves to increase the effect. A very slow LFO rate is usually best for a realistic
effect, but a faster LFO rate can also be useful with minimal LFO depth (.2). Since this is
a stereo chorus, an LFO phase parameter is included which can be used to widen the
stereo image.
Compressor
In its simplest form, an audio compressor is just an automatic gain control. When the
volume gets too loud, the compressor automatically turns it down. Compressors are
useful in musical applications because they allow you to record a “hotter” signal
without overloading the recording device.
Since the compressor turns down the gain of the signal, you might wonder how can it
make the signal level stronger. A Post Gain control allows you to boost the output gain
of the compressor in order to make up for the gain reduction. The overall level is higher
and only turned down when the signal level gets too loud. This level is called the
Threshold, which just happens to be the most important control on the compressor.
Parameter Description
Delay Sets the length of the delay. Range: 0ms to 20ms.
Feedback Sets the amount of delayed signal that will be recirculated through
the delay line. Range: 0% to 100%
LFO Rate Sets the frequency of the low frequency oscillator.
Range: .01Hz to 10Hz
LFO Depth Sets how much the LFO affects the delay time. Increases the
animation and amount of the chorus effect. Range: 0% to 100%
LFO Waveform Selectable between Sine or Triangle wave.
LFO L/R Phase Controls the stereo width by adjusting the phase difference of the LFO
waveform between left and right channels. Range: -180° to +180°
In
Out
Threshold
Ratio
Attack Release
Post Gain
Signal path = Stereo
VCA
Level
Control
Delay