Soundtoys PhaseMistress - Manual (Page 8)

What’s a Phase Shifter?
(For those in the know you can skip this section)
The original Phase-Shifter effect was an attempt at electronically recreating analog
tape flanging – (an effect created by mixing the output of two analog tape machines
playing the same track, only slightly out of sync) using integrated circuits. Early
effects designers attempted to model the ‘out of sync’ part of the flanging effect by
using something called an analog phase shift circuit. The result wasn’t exactly tape
flanging (as real flanging requires a short modulated delay), but the resulting effect
though different sounded tres’ cool, especially on guitar. Enter Jim Hendrix, the
Univox "Univibe"® and the rest as they say is history.
A phaser or phase shift effect is created by altering the phase of the audio, (kinda
like delay, but varying with frequency) and mixing this phase-shifted sound back in
with the original signal. The resulting phase cancellation produces a wonderfully
musical sounding set of "notches" at musically related frequencies in the original
sound. By sweeping, or modulating the phase-shifted signal, the notch frequencies
are moved up and down the frequency spectrum thus creating that classic swooshy
and swirly phase-shift sound.
Analog phasers can have different numbers of phase shift ‘stages’ in their design,
producing more or less phase shift through the circuit. As you add stages to the
phase shift "circuit" (resulting in more notches), the overall "strength" of the phase
shift effect increases and becomes more prominent. In addition, the number of
stages significantly affects the overall tonal character of the phased sound. A 2-
stage phaser will be very "washy" and wet (think Hendrix "Machine Gun", Robin
Trower’s "Bridge of Sighs" and the opening guitar on Dark Side of the Moon’s
"Breath"). The totally cool phased drum sound on Led Zeppelin’s "Kashmir" from
Physical Graffiti was created with a 4 stage phaser that provided a much more pro-
nounced effect. So it kind of stands to reason that 6, 8, 10 and 12 stage phasers each
sound progressively more pronounced.
One thing you might also notice that these are all even numbers. Using an odd num-
ber of stages sounds totally different than an even number of stages and for some
reason (at least until now) virtually all phasers stuck to only even numbers.
PhaseMistress on the other hand allows you to pick any number of stages between 2
and 24 including all odd numbers. This expands the tonal palate exponentially allow-
ing you to make an even number of even or odd sounds, an odd number of odd or
even sounds as well as making really odd sounding even phasers…and so on and so
forth.
Some of the most popular phasers over the years have include the old Univox
Univibe, MXR Phase 90, Electro-Harmonix Small-Stone, Eventide Instant Phaser and
the Mutron Bi-Phase which had two distinct phasers in one box. These phasers and
the phasing effect in general have been used by literally hundreds of artists and on
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U S I N G P H A S E M I S T R E S S