PitchDoubler is a fully stereo, pitch shifting doubler effect (generating the effect of additional voices from its input). It is based on the same pitch shifting technology as VocalShift, with the associated low latency (<6ms), wide frequency range (down to around 80Hz) and minimal phasing / flutter artefacts. The effect squeezes two channels of high quality pitch shifting into a single effect slot, along with further features such as adjustable delay and modulation. The PitchDoubler has completely independent left and right channels, which can be mixed to the left/right outputs of the effect by means of the stereo width control. The doubling effect is achieved by provision of time delay, and modulated pitch shift. Sliders are provided on each channel for independent control of the delay (0 - 25ms) and the pitch shift (-100 -> +100). A pitch modulation LFO module, with adjustable rate and depth, provides a natural variation in the pitch shift.