The Ultimate Voice Changer can be used to make very realistic Dalek voices. The BBC originally used a ring modulator to create this iconic voice. Luckily, this effect is easy to replicate in software by mixing a sine wave with the audio input. The frequency of the since wave can be varied for different effects. The classic Dalek voice from the original series generally used a 30 Hz sine wave, although the NSD (New Series Dalek) uses a 25 Hz sine wave.
The Ultimate Voice Changer has an on-board LED as well as a terminal block for attaching external LEDs. This is ideal for connecting to the dome lights in a Dalek.