ABSTRACT
Vibrato is the effect caused by rapid and subtle alteration of pitch. Such an effect can be part of a vocal performance, is an extremely common playing technique with string instruments, a known technique for guitars and can also be the byproduct of the Doppler effect as produced by a Leslie cabinet (which was originally called a ‘Vibratone’). Vibrato can be achieved by modulating a delay line – without mixing the source signal. Subtle settings create similar effects to those that occur in nature. The evident pitch shifting caused by more aggressive settings will make the effect very obvious and unnatural (although this can still be used to creative effect in certain circumstances). The actual settings involve:
• Dry/wet: fully wet, dry signal not mixed. • Delay time: between 3 and 8ms. • Modulation depth: around 25% (2ms). This control is used for more or less effect. • Modulation rate: around 3Hz. • Feedback: none.
