ampeg_attack

EG attack time.

Examples #

ampeg_attack=1.2
fileg_attack=0.1

Practical Considerations #

These are very frequently used, especially with amplifier envelopes. ampeg_attack is the standard “A” in the basic ADSR volume envelope. fileg_attack is key to 303-style basses.

In ARIA, the SFZ1 envelopes have linear attack (for pitcheg and fileg, probably linear in cents, which won’t translate into linear in Hertz). Decay and release stages have a curve which is faster than linear, and it seems to match “well enough” with a multiplicatively decreasing curve. The step size should be close to \(\mu = \exp \left( - \frac{8.0}{t \times s} \right)\) where \(t\) is the decay duration in seconds, and \(s\) is the sample rate in Hertz. The envelope \(x_{n+1}\) at index \(n+1\) is thus computed as \(x_{n+1} = \mu \times x_{n}.\)

Here is a screenshot of a file output using Sforzando, showing the ampeg_envelope shape and its stages.

Category: Modulation, Envelope Generators