FM Controls

FM Power Switch

Turns the FM modulating oscillator ON or OFF.

FM Keyboard Tracking

The small music keyboard switch enables or disables Keyboard Tracking. The Keyboard Tracking button determines whether the modulator oscillator tracks the keyboard.

If the Keyboard Tracking is turned ON, then the modulator oscillator will track the keyboard, meaning it will change pitch with the keyboard. If Keyboard Tracking is OFF, the modulation oscillator will not change pitch with the keyboard, it will remain on the same pitch no matter which key is played. This can be useful for more clangorous or percussive sounds.

FM Frequency

Controls the frequency of the modulator oscillator. Because the modulator is unheard, it does not change the pitch of the original Soundsource. Instead it alters the timbral characteristics of the Soundsource waveform.

When this horizontal slider is set to just above the minimum, it can produce LFO-type pitch effects. Moving the slider towards the maximum increases the frequency and begins to oscillate fast enough that it will introduce timbre changes.

The notches along the FREQUENCY slider are markers for the frequency ratios that will produce the most musically useful results.

These musically useful values at the notches are decimal versions of these ratios – 1/4, 1/2, 3/4 and 1 – represented as .250, .500. .750 and 1.00.
Range 0.000 to 1.000

FM Depth

Controls the modulator’s depth. The higher the DEPTH slider is set, the more the dedicated modulator is affecting the timbre of the Soundsource.
Range 0.000 to 1.000

FM Waveform

Many FM synthesizers use only Sine waves, but Trilian’s modulator can use any one of four different waveforms. The four mode switches are for Sine, Triangle, Sawtooth, and Noise. Each successive waveform has more overtones and so will add a brighter timbre.

In general FM works better when beginning with a simpler, more pure sound than a sound with a lot of complexity.