The filter has the biggest effect on the sound’s character or “timbre.” It affects the timbre by changing the relative volume of certain frequencies in the sound. Use it to give the impression that a sound is “brighter” (more high frequencies) or “darker” (more low frequencies). The "cutoff" knob sets the frequency to be emphasized, while the "peak" knob controls the intensity of the filter. If the peak is turned up all the way, the filter turns into an oscillator!

The filter allows you to sculpt the tone of your sounds. The filter is a modifier, a synthesizer element that directly affects the sound of the signal generator. They can either reduce or enhance characteristics of sound and manipulate waveforms. If the cutoff knob is fully counterclockwise, it cuts off the tone completely, darkening the oscillator’s sound. When the knob is fully clockwise, the filter is open and allows the oscillator’s tone to pass through. The peak knob emphasizes the intensity of the filter, capable of creating deep bass or high-pitched frequencies.

The filter is know as a low-pass filter. This means that frequencies higher than a certain point will be reduced or filtered out. When the peak is increased and the cutoff is adjested, the timbral effect can sound like a person making vowel like sounds.