The Effects
72
Pitch Shifter
The Axe-Fx Ultra Pitch Shifter has ten modes of operation: Detune, Fixed Harmony, Intelligent
Harmony, Classic Whammy, Octave Divider, Crystals, Advanced Whammy, Arpeggiator, Custom
Shifter and Auto Pitch. The mode is selected with the
TYPE
parameter on the first page.
The Pitch Shifter can use one of two different algorithms when in the Fixed Harmony or Whammy
modes. The algorithm is selected using the
PITCH TRACK
control. When set to
ON
, the Pitch Shifter
will track the pitch of the incoming note and adjust various internal parameters accordingly. Setting
PITCH TRACK
to
OFF
ignores the pitch data and uses fixed parameter values. With pitch tracking
off the sound can waver or flutter depending upon the note(s) played. With pitch tracking on the
sound is typically smoother but complex chords may cause pitch instabilities.
The Pitch Shifter also allows you to select the source of the pitch data that the shifter will use when
making pitch calculations. The global detector is unaffected by routings and is usually the best
choice for single note usage. The integrated detector uses the signal input to the pitch block
including any feedback within the block. This can enhance pitch stability when using feedback,
whether internally, using the
FEEDBACK
parameters, or using the feedback blocks. When using the
global detector and pitch feedback the pitched notes may sound a bit off if you stop playing since
there will be no signal to determine pitch from. By using the internal detector the pitch block is
always obtaining pitch information even when you stop playing.
The integrated detector may not work as well, however, if the data input to the block is distorted in
amplitude or time (i.e. reverb, chorus, etc.).
The
PITCH SOURCE
parameter has three settings:
GLOBAL
- In this mode the pitch information comes from the global pitch detector connected
directly to the main inputs. This detector is optimized for speed and accuracy when playing single
notes.
LOCAL MONO
- In this mode the pitch information comes from the integrated pitch detector
connected to the input of the pitch block. In this mode the detector is optimized for speed and
accuracy when playing single notes. By using the input of the block as the data source this detector
can continue to track pitch if you are using feedback into the block and stop playing.
LOCAL POLY
- In this mode the pitch information comes from the integrated pitch detector
connected to the input of the pitch block. In this mode the detector is optimized for polyphonic
sources, i.e. chords. The pitch tracking is necessarily slower but is more stable when playing
multiple notes. Due to the inexact definition of pitch for chords, the pitch detector may have
difficulty finding pitch on complex chord types. Simple chords, diads and triads, work best.
Common Parameters
The first menu page has several common parameters for the pitch block.
TYPE -
Sets the sub-algorithm to use.
INGAIN -
Sets the input level to the block. You can use this to control the amount of signal input to
the pitch shifters. Often times this is attached to a modifier to allow swell-type effects.
