A simple and small nodejs module for creating an adsr gain node

Usage no npm install needed!

<script type="module">
  import adsrGainNode from '';



Simple object for getting an ADSR gain node


npm install --save adsr-gain-node

Example usage

var adsrGainNode = require('adsr-gain-node')
var audioCtx = new AudioContext();

var oscillator = audioCtx.createOscillator();

// Helper function to get new gain node
function getADSR () {
    let adsr = new adsrGainNode(audioCtx);
        attackAmp: 0.001, 
        decayAmp: 0.3,
        sustainAmp: 0.7,
        releaseAmp: 0.001,
        attackTime: 1.1,
        decayTime: 0.2,
        sustainTime: 1.0, 
        releaseTime: 5.0,

         * If you are making e.g. a keyboard, then you may 
         * not auto-release the note
         * If auto release is false then
         * you should release the note using. 
         * `adsr.releaseNow()´
        autoRelease: true
    return adsr

// Begin time for gain
var nowTime = audioCtx.currentTime

// Get adsr and the gain node
// Time it to begin in current time + 5 secs
let testTime = 2

var adsr = getADSR()
var gainNode = adsr.getGainNode(nowTime + testTime );

// Connect the oscillator to the gain node

// Start
oscillator.start(nowTime + testTime);

// Stop oscillator according to the ADSR
let endTime = adsr.releaseTime() + testTime

// On a piano you may want to release the note, when
// the key is released. 
// Then you may do something like this to end the note and the gain node: 
// E.g onKeyUp: 
//     oscillator.stop(this.adsr.releaseTimeNow())
//     adsr.releaseNow()

There is also a HTML form which can generate a web interface for the control of gain nodes.

You can see it on

The source is test.js


MIT © Dennis Iversen