EG attack time.
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
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
where is the decay duration in seconds, and is the sample rate in Hertz.
The envelope at index is thus computed as
Here is a screenshot of a file output using Sforzando, showing the ampeg_envelope shape and its stages.
|ampeg_attack||SFZ v1||float||0||0 to 100||seconds|
|ampeg_attackccN||SFZ v1||float||0||-100 to 100||seconds|
|ampeg_vel2attack||SFZ v1||float||0||-100 to 100||seconds|
- Envelope: X
- LFO: X
- MIDI CC:
- ampeg_attackccN (SFZ v1), alias ampeg_attack_onccN (SFZ v2)
- ampeg_vel2attack (SFZ v1)