Difference between revisions of "Envelope generator"

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[[File:ADSR parameter.svg|thumb|300px|The amplitude over time of an ADSR envelope. Only the positive half of the signal is shown.]] Sound synthesis techniques often employ an '''envelope generator''', '''contour generator''' or '''transient generator''' that controls some parameters of a signal or control voltage at any point in its duration. When it controls a [[VCA]] these together form an envelope shaper or loudness contour.<ref>''Synthesizers for musicians'' by R A Penfold, PC Publishing, 1989, ISBN 1-870775-01-5, p.21</ref><ref>''Beginning Synthesizer'' by Helen Casabona, David Frederick, Tom Darter, Alfred Publishing Company Inc, 1986, ISBN 0882843532</ref>
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[[File:ADSR parameter.svg|thumb|300px|The amplitude over time of an ADSR envelope. Only the positive half of the signal is shown.]] Sound synthesis techniques often employ an '''envelope generator''', '''contour generator''' or '''transient generator''' that controls some parameters of a signal or control voltage at any point in its duration. When it controls a [[VCA]] these together form an envelope shaper or loudness contour.<ref>''Synthesizers for musicians'' by R A Penfold, PC Publishing, 1989, {{ISBN|1-870775-01-5}}, p.21</ref><ref>''Beginning Synthesizer'' by Helen Casabona, David Frederick, Tom Darter, Alfred Publishing Company Inc, 1986, {{ISBN|0882843532}}</ref>
   
 
== Timbre ==
 
== Timbre ==
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== ADSR ==
 
== ADSR ==
Most often the envelope generator is an ADSR (Attack Decay Sustain Release), which may be applied to overall [[amplitude]], [[frequency]], or [[filter]]. It is usually triggered by a [[gate]] signal from the keyboard.<ref name="q109">Synthesizers.com [http://www.synthesizers.com/q109.html Q109 Envelope Generator]</ref>
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Most often the envelope generator is an ADSR (Attack Decay Sustain Release), which may be applied to overall [[amplitude]], [[frequency]], or [[Voltage controlled filter|filter]]. It is usually triggered by a [[gate]] signal from the keyboard.<ref name="q109">Synthesizers.com [http://www.synthesizers.com/q109.html Q109 Envelope Generator]</ref>
   
 
The contour of an ADSR envelope is specified using four parameters:
 
The contour of an ADSR envelope is specified using four parameters:
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<!--== See also ==-->
 
<!--== See also ==-->
{{From Wikipedia|Synthesizer}}
 
   
 
== References ==
 
== References ==
 
{{From Wikipedia|Synthesizer}}
 
{{Reflist}}
 
{{Reflist}}
{{Lacks references}}
 
   
 
== Further reading ==
 
== Further reading ==
* ''The Complete Guide to Synthesizers'' by Devarahi, Prentice Hall, 1982, ISBN 0-13-160630-1, pages 74-91
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* ''The Complete Guide to Synthesizers'' by Devarahi, Prentice Hall, 1982, {{ISBN|0-13-160630-1}}, pages 74–91
   
 
== External links ==
 
== External links ==
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* [https://github.com/micjamking/synth-secrets/blob/master/part-8.md Synth Secrets, Part 8: More About Envelopes]
 
* [https://github.com/micjamking/synth-secrets/blob/master/part-8.md Synth Secrets, Part 8: More About Envelopes]
 
* [http://173.201.189.104/forum/viewtopic.php?t=31473 What are all the ADSR's out there to build?] on electro-music.com
 
* [http://173.201.189.104/forum/viewtopic.php?t=31473 What are all the ADSR's out there to build?] on electro-music.com
* Muff's Modules & More Forum:[https://www.muffwiggler.com/forum/viewtopic.php?t=83193 CEM3310 equivalent circuit]
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* Muff's Modules & More Forum:[https://www.modwiggler.com/forum/viewtopic.php?t=83193 CEM3310 equivalent circuit]
 
=== Kits ===
 
=== Kits ===
* MFOS [http://www.musicfromouterspace.com/index.php?CATPARTNO=NONE&PROJARG=ADSR001%2FADSR001.html&MAINTAB=SYNTHDIY&VPW=1150&VPH=777 ADSR Envelope Generator]
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* MFOS [https://web.archive.org/web/20190614005053/http://musicfromouterspace.com/index.php?CATPARTNO=NONE&PROJARG=ADSR001%252FADSR001.html&MAINTAB=SYNTHDIY&VPW=1150&VPH=777 ADSR Envelope Generator]
* MFOS [http://www.musicfromouterspace.com/index.php?CATPARTNO=NONE&PROJARG=DUALARGENERATOR%2FDUALARGENERATOR.html&MAINTAB=SYNTHDIY&VPW=1150&VPH=777 Dual Attack Release Envelope Generator]
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* MFOS [https://web.archive.org/web/20190614005048/http://musicfromouterspace.com/index.php?CATPARTNO=NONE&PROJARG=DUALARGENERATOR%252FDUALARGENERATOR.html&MAINTAB=SYNTHDIY&VPW=1150&VPH=777 Dual Attack Release Envelope Generator]
 
* [https://web.archive.org/web/20120815070312/http://www.cgs.synth.net/modules/cgs116_env.html Serge Extended ADSR Envelope Generator]
 
* [https://web.archive.org/web/20120815070312/http://www.cgs.synth.net/modules/cgs116_env.html Serge Extended ADSR Envelope Generator]
 
* Oakley [http://www.oakleysound.com/vc-adsr.htm Voltage Controlled ADSR and VCA module]
 
* Oakley [http://www.oakleysound.com/vc-adsr.htm Voltage Controlled ADSR and VCA module]
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==== Readily available analogue IC and discrete component based ====
 
==== Readily available analogue IC and discrete component based ====
   
* Formant music synthesizer by [[C. Chapman]], Elektor, 1978, p. 64, using [[Operational amplifier|op-amps]] and common [[discrete]] components
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* Formant music synthesizer by [[C. Chapman]], Elektor, 1978, p.&nbsp;64, using [[Operational amplifier|op-amps]] and common [[discrete]] components
 
* [http://yusynth.net/Modular/EN/ADSR/index.html yusynth ADSR] has a [[555]] core with a few op-amps.
 
* [http://yusynth.net/Modular/EN/ADSR/index.html yusynth ADSR] has a [[555]] core with a few op-amps.
* ''[https://sdiy.info/wiki/File:The_Reprint_Collection_by_Thomas_Henry_CC_BY_NC.pdf ADSR the Easy Way]'' by Thomas Henry, Polyphony, March/Apil 1982, pp. 22,23,30,3I.
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* ''[https://web.archive.org/web/20190613221410/https://sdiy.info/wiki/File%3AThe_Reprint_Collection_by_Thomas_Henry_CC_BY_NC.pdf ADSR the Easy Way]'' by Thomas Henry, Polyphony, March/Apil 1982, pp.&nbsp;22,23,30,3I.
 
* [https://www.schmitzbits.de/adsr.html Envelope ADSR schematics on Schmitzbits] - 3 envelope schematics based on readily available components.
 
* [https://www.schmitzbits.de/adsr.html Envelope ADSR schematics on Schmitzbits] - 3 envelope schematics based on readily available components.
   
 
==== CEM IC based ====
 
==== CEM IC based ====
   
* Digisound 80 [http://www.digisound80.co.uk/digisound/modules/80-10/80-10.htm 80-10 Voltage Controlled Envelope Generator], uses [[CEM3310]]. ''Electronic Music Circuits'' by [[Barry Klein]],1982, p. 62-3, includes [[Charles Blakey]]'s independent trigger input modification.
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* Digisound 80 [http://www.digisound80.co.uk/digisound/modules/80-10/80-10.htm 80-10 Voltage Controlled Envelope Generator], uses [[CEM3310]]. ''Electronic Music Circuits'' by [[Barry Klein]],1982, p.&nbsp;62-3, includes [[Charles Blakey]]'s independent trigger input modification.
 
* Digisound 80 [http://www.digisound80.co.uk/digisound/modules/80-8/80-8.htm 80-8 Dual ADSR], uses CEM3310
 
* Digisound 80 [http://www.digisound80.co.uk/digisound/modules/80-8/80-8.htm 80-8 Dual ADSR], uses CEM3310
 
* Digisound 80 [http://www.digisound80.co.uk/digisound/modules/80-18/80-18.htm 80-18 Dual Multi-Function Envelope Generator], uses CEM3310
 
* Digisound 80 [http://www.digisound80.co.uk/digisound/modules/80-18/80-18.htm 80-18 Dual Multi-Function Envelope Generator], uses CEM3310

Revision as of 17:22, 24 April 2021

The amplitude over time of an ADSR envelope. Only the positive half of the signal is shown.

Sound synthesis techniques often employ an envelope generator, contour generator or transient generator that controls some parameters of a signal or control voltage at any point in its duration. When it controls a VCA these together form an envelope shaper or loudness contour.[1][2]

Timbre

ADSR envelope generators can be used for various functions. The most important use is to give timbre to a sound. Timbre is what makes one instrument sound distinct from another, even when playing the same note and at the same volume.

ADSR

Most often the envelope generator is an ADSR (Attack Decay Sustain Release), which may be applied to overall amplitude, frequency, or filter. It is usually triggered by a gate signal from the keyboard.[3]

The contour of an ADSR envelope is specified using four parameters:

Attack time
The time taken for initial run-up of level from nil to peak, beginning when the key is first pressed.
Decay time
The time taken for the subsequent run down from the attack level to the designated sustain level.
Sustain level
The level during the main sequence of the sound's duration, until the key is released.
Release time
The time taken for the level to decay from the sustain level to zero after the key is released.

A common variation of the ADSR on some synthesizers, such as the Korg MS-20, was ADSHR (attack, decay, sustain, hold, release). By adding a "hold" parameter, the system allowed notes to be held at the sustain level for a fixed length of time before decaying. The General Instrument AY-3-8910 IC included a hold time parameter only; the sustain level was not programmable. Another common variation in the same vein is the AHDSR (attack, hold, decay, sustain, release) envelope, in which the "hold" parameter controls how long the envelope stays at full volume before entering the decay phase.

Certain synthesizers also allow for a delay parameter before the attack. Modern synthesizers like the DSI Prophet 8 have DADSR (delay, attack, decay, sustain, release) envelopes. The delay setting determines the length of silence between hitting a note and the attack.

Usage

For shorter envelopes at higher pitch, as happens in acoustic instruments, a master CV is taken from the same voltage as used for VCO pitch.[4]


References

This page uses Creative Commons Licensed content from Wikipedia:Synthesizer (view authors).

  1. ^ Synthesizers for musicians by R A Penfold, PC Publishing, 1989, ISBN 1-870775-01-5, p.21
  2. ^ Beginning Synthesizer by Helen Casabona, David Frederick, Tom Darter, Alfred Publishing Company Inc, 1986, ISBN 0882843532
  3. ^ Synthesizers.com Q109 Envelope Generator
  4. ^ Description of the Serge Extended ADSR Envelope Generator

Further reading

  • The Complete Guide to Synthesizers by Devarahi, Prentice Hall, 1982, ISBN 0-13-160630-1, pages 74–91

External links

Kits

Schematics

Readily available analogue IC and discrete component based

CEM IC based