Sample And Hold Node

Samples a signal at regular intervals, and holds the sampled value for the remainder of that interval. That is, this Node takes snapshots of the signal periodically, and holds the last value until the next snapshot:

input:  0 1 2 3 4 5 6 ...
output: 0 0 0 3 3 3 6 ...
        ^     ^     ^

The Sample And Hold Node works well for audio and control signals alike. For audio signals, you can use it for downsampling, which adds quantization noise. For control signals, you can use it to convert a gradually changing signal to a series of steps over time.


Inputs

Audio/Control Input

The signal to periodically sample, and then hold on that sample.

Ratio-Control Input

Controls the value of the Ratio setting (when enabled). You can enable this input from the Ratio setting, and it’s disabled by default.


Settings

Mode

This setting is mostly visual, and is here merely to help you switch the period mode between either Ratio and Duration, depending on what you need. See below.

Ratio

Specifies the hold period as a percentage of the current sample rate, a technique also known as downsampling. For example, if you set it to 75%, every 4th sample is held (for the duration of 3 additional samples).

This mode works well with audio signals, where you only want to hold a few samples at a time to keep the signal audible. You can also automate this setting from the Ratio-Control Input.

Note, that because this setting is relative to the sample rate, the outcome will be slightly different depending on your sample rate. The most obvious difference is that the quantization noise added by downsampling appears at a different frequency range.

Duration

Specifies the hold duration directly, in milliseconds. That is, this is the duration for which the Node will hold a sample, before taking the next snapshot.

This mode works well with control signals, where you may want to hold samples for longer durations (e.g. several milliseconds, or even seconds). Keep in mind, that any value which is “not very low” will downsample audio signals so much that it will most often become inaudible.


Outputs

Audio/Control Output

The same audio/control signal, but with some (or most) samples held based on previous samples.


Similar Nodes

  • The downsampling part of the Bitcrusher Node also uses a sample-and-hold effect internally, and yields pretty much the same effect