PulseOscillator is an oscillator with control over pulse width, also known as the duty cycle. At 50% duty cycle (width = 0) the wave is a square wave. Read more.

``` width = -0.25 width = 0.0 width = 0.25

return Tone.Offline(() => {
	const pulse = new Tone.PulseOscillator(50, 0.4).toDestination().start();
}, 0.1, 1);



new PulseOscillator (
frequency?:Frequency ,

The frequency of the oscillator


The width of the pulse

) => PulseOscillator
new PulseOscillator (
options?:Partial<PulseOscillatorOptions >
) => PulseOscillator


baseType #

readonly "pulse"

The baseType of the oscillator. Always returns "pulse".

blockTime #

readonly Seconds

The number of seconds of 1 processing block (128 samples)


carrierType #

Internal use The carrier oscillator type is fed through the waveshaper node to create the pulse. Using different carrier oscillators changes oscillator's behavior.

channelCount #


channelCount is the number of channels used when up-mixing and down-mixing connections to any inputs to the node. The default value is 2 except for specific nodes where its value is specially determined.

channelCountMode #


channelCountMode determines how channels will be counted when up-mixing and down-mixing connections to any inputs to the node. The default value is "max". This attribute has no effect for nodes with no inputs.

  • "max" - computedNumberOfChannels is the maximum of the number of channels of all connections to an input. In this mode channelCount is ignored.
  • "clamped-max" - computedNumberOfChannels is determined as for "max" and then clamped to a maximum value of the given channelCount.
  • "explicit" - computedNumberOfChannels is the exact value as specified by the channelCount.

channelInterpretation #


channelInterpretation determines how individual channels will be treated when up-mixing and down-mixing connections to any inputs to the node. The default value is "speakers".

context #


The context belonging to the node.

debug #


Set this debug flag to log all events that happen in this class.

detune #

Signal<"cents" >

The detune in cents.

disposed #

readonly boolean

Indicates if the instance was disposed. 'Disposing' an instance means that all of the Web Audio nodes that were created for the instance are disconnected and freed for garbage collection.

frequency #

Signal<"frequency" >

The frequency control.

input #


Sources have no inputs

mute #


Mute the output.

const osc = new Tone.Oscillator().toDestination().start();
// mute the output
osc.mute = true;

numberOfInputs #

readonly number

The number of inputs feeding into the AudioNode. For source nodes, this will be 0.

const node = new Tone.Gain();

numberOfOutputs #

readonly number

The number of outputs of the AudioNode.

const node = new Tone.Gain();

onstop #


The callback to invoke when the source is stopped.

output #


The output note

partialCount #

readonly number

No partials for this waveform type.

partials #

readonly number []

The partials of the waveform. Cannot set partials for this waveform type

phase #


The phase of the oscillator in degrees.

sampleTime #

readonly Seconds

The duration in seconds of one sample.


state #

readonly BasicPlaybackState

Returns the playback state of the source, either "started" or "stopped".

const player = new Tone.Player("https://tonejs.github.io/audio/berklee/ahntone_c3.mp3", () => {

type #

readonly "pulse"

The type of the oscillator. Always returns "pulse".

static version #


The version number semver

volume #

Param<"decibels" >

The volume of the output in decibels.

const source = new Tone.PWMOscillator().toDestination();
source.volume.value = -6;

width #

Signal<"audioRange" >

The width of the pulse.

return Tone.Offline(() => {
	const pulse = new Tone.PulseOscillator(20, 0.8).toDestination().start();
}, 0.1, 1);


asArray #

Returns an array of values which represents the waveform.

asArray (
length= 1024:number
) => Promise<Float32Array >

chain #

Connect the output of this node to the rest of the nodes in series.

const player = new Tone.Player("https://tonejs.github.io/audio/drum-samples/handdrum-loop.mp3");
player.autostart = true;
const filter = new Tone.AutoFilter(4).start();
const distortion = new Tone.Distortion(0.5);
// connect the player to the filter, distortion and then to the master output
player.chain(filter, distortion, Tone.Destination);
chain (
...nodes:InputNode []
) => this

connect #

connect the output of a ToneAudioNode to an AudioParam, AudioNode, or ToneAudioNode

connect (
destination:InputNode ,

The output to connect to

outputNum= 0:number ,

The output to connect from

inputNum= 0:number

The input to connect to

) => this

disconnect #

disconnect the output

disconnect (
destination?:InputNode ,
outputNum= 0:number ,
inputNum= 0:number
) => this

dispose #

Clean up method.

dispose ( ) => this

fan #

connect the output of this node to the rest of the nodes in parallel.

const player = new Tone.Player("https://tonejs.github.io/audio/drum-samples/conga-rhythm.mp3");
player.autostart = true;
const pitchShift = new Tone.PitchShift(4).toDestination();
const filter = new Tone.Filter("G5").toDestination();
// connect a node to the pitch shift and filter in parallel
player.fan(pitchShift, filter);
fan (
...nodes:InputNode []
) => this

get #

Get the object's attributes.

const osc = new Tone.Oscillator();

static getDefaults #

Returns all of the default options belonging to the class.

getDefaults ( ) => PulseOscillatorOptions

immediate #

Return the current time of the Context clock without any lookAhead.

setInterval(() => {
}, 100);
immediate ( ) => Seconds

now #

Return the current time of the Context clock plus the lookAhead.

setInterval(() => {
}, 100);
now ( ) => Seconds

restart #

Restart the source.

restart (
time?:Time ,
offset?:Time ,
) => this

set #

Set multiple properties at once with an object.

const filter = new Tone.Filter().toDestination();
// set values using an object
	frequency: "C6",
	type: "highpass"
const player = new Tone.Player("https://tonejs.github.io/audio/berklee/Analogsynth_octaves_highmid.mp3").connect(filter);
player.autostart = true;
set ( ) => this

start #

Start the source at the specified time. If no time is given, start the source now.

const source = new Tone.Oscillator().toDestination();
source.start("+0.5"); // starts the source 0.5 seconds from now
start (
time?:Time ,

When the source should be started.

offset?:Time ,
) => this

stop #

Stop the source at the specified time. If no time is given, stop the source now.

const source = new Tone.Oscillator().toDestination();
source.stop("+0.5"); // stops the source 0.5 seconds from now
stop (

When the source should be stopped.

) => this

sync #

Sync the source to the Transport so that all subsequent calls to start and stop are synced to the TransportTime instead of the AudioContext time.

const osc = new Tone.Oscillator().toDestination();
// sync the source so that it plays between 0 and 0.3 on the Transport's timeline
// start the transport.
// set it to loop once a second
Tone.Transport.loop = true;
Tone.Transport.loopEnd = 1;
sync ( ) => this

toDestination #

Connect the output to the context's destination node.

const osc = new Tone.Oscillator("C2").start();
toDestination ( ) => this

toFrequency #

Convert the input to a frequency number

const gain = new Tone.Gain();
toFrequency (
) => Hertz


Connect the output to the context's destination node. See toDestination

toMaster ( ) => this

toSeconds #

Convert the incoming time to seconds. This is calculated against the current Tone.Transport bpm

const gain = new Tone.Gain();
setInterval(() => console.log(gain.toSeconds("4n")), 100);
// ramp the tempo to 60 bpm over 30 seconds
Tone.getTransport().bpm.rampTo(60, 30);
toSeconds (
) => Seconds

toString #

Convert the class to a string

const osc = new Tone.Oscillator();
toString ( ) => string

toTicks #

Convert the input time into ticks

const gain = new Tone.Gain();
toTicks (
time?:Time | TimeClass
) => Ticks

unsync #

Unsync the source to the Transport. See Source.sync

unsync ( ) => this