Pitch shifter

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The Axe-Fx Pitch Shifter has six basic modes of operation: Detune, Fixed Harmony, Intelligent Harmony, Whammy, Octave Divider, and Crystals. The Ultra adds Advanced Whammy, Arpeggiator, Custom Shifter and Auto Pitch. The mode is selected on the TYPE 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 Ultra pitchshifter 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 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.

Detune

The Detune mode creates two voices that are slightly detuned from the input. The amount of detuning is adjustable between -50 and +50 cents. This mode is useful for creating double-tracked sounds or chorus-like effects.

Parameters

  • V1,2 - Sets the detune amount for each voice. Attaching an LFO to these can be used to create chorus effects.
  • LVL1,2 - Sets the volume level of the voice.
  • PAN1,2 - Sets the panning of the voice.


Fixed harmony

The Fixed Harmony mode creates two voices that are fixed intervals from the input.

Parameters

  • VOICE1,2 DETUNE - Sets the detune amount of the voice in cents. The range of +/- 50 cents. You can attach a controller to the detunes by pressing enter.
  • VOICE1,2 SHIFT - Sets the shift amount of the voice in half-steps. The range of shift is +/- 12 half-steps.
  • VOICE1,2 LEVEL - Sets the volume level of the voice.
  • VOICE1,2 PAN - Sets the panning of the voice.
  • VOICE1,2 DELAY - Sets the delay time of the as a function of the tempo.
  • VOICE1,2 DLYTEMPO - Locks the delay time to the global tempo. For example, if the global tempo is 120 bpm and the tempo is set to a quarter note (1/4) then the time will be 500 ms (one echo per beat). To ignore the global tempo set the tempo control to NONE.
  • VOICE1,2 FEEDBACK - Sets the feedback of the voice to the input. By delaying and feeding a voice back strange pitch effects can be created as the note is translated pitch again and again.
  • PITCH TRACK - Setting this to ON instructs the pitch shifter to track the pitch of the input. For single note work this provides improved results. For chordal work this should be set to OFF as the pitch tracker obviously cannot determine the pitch of simultaneous tones.
  • TRACK ADJUST - This control allows fine-tuning the pitch shifter “splice length”. For large shifts this control can help improve the quality of the shifted note.


Intelligent harmony

The Intelligent Harmony mode creates two voices that track the note you’re playing and remain within the key.

Parameters

  • KEY - Sets the key that the harmony will be in.
  • SCALE - Sets the type of scale (or scale mode) that the harmony will use. Examples are Ionian (major), Aeolian (minor), Whole Tone, etc. Set to CUSTOM to use custom scale tones (see below).
  • TRACK MODE - Sets mode in which the harmony will track the input. SMOOTH allows the harmony note to follow bends and vibrato in the input. STEPPED locks the harmony to the nearest chromatic tone.
  • TRACKING - Controls the tracking of the pitch shifter. Adjust for best sound. Higher values tend to sound better for higher shifts and vice-versa.
  • GLIDE TIME - Sets the rate at which the harmony moves from the existing pitch to a new pitch.
  • VOICE1,2 HARMONY - Sets the scale degree the voice will sound.
  • VOICE1,2 DELAY - Sets the delay time of the voice in milliseconds.
  • VOICE1,2 DLYTEMPO - Locks the delay time to the global tempo. For example, if the global tempo is 120 bpm and the tempo is set to a quarter note (1/4) then the time will be 500 ms (one echo per beat). To ignore the global tempo set the tempo control to NONE.
  • CUSTOM NOTES - Sets the number of notes when using a custom scale. Custom scales can have between four and eight notes.
  • TONIC - Sets the reference note for entering the custom scale. This is not a stored parameter and only serves to aid in defining the custom scale. Setting this to “C” allows defining your custom scale with C as the tonic. The actual key that the harmony will be in is set using the KEY parameter.
  • NOTEn - These are the notes of your custom scale relative to the tonic set by TONIC. Set these to define the scale degrees.


Classic whammy

The Whammy mode allows control of the pitch shift via a control knob (normally you would connect this knob to a controller such as an expression pedal). There are two sub-modes: Whammy-Up and Whammy-Down. The difference between the sub-modes is the direction of the pitch shift. In Whammy-Up mode the pitch increases as the control is increased. In Whammy-Down mode the pitch decreases as the control in increased.

Parameters

  • MODE - Selects the Whammy mode. Various amounts of shift are possible up to two octaves up and down.
  • CONTROL - Adjusts the output pitch. Attach to a controller for dynamic control of the pitch.
  • PITCH TRACK - Setting this to ON instructs the pitch shifter to track the pitch of the input. For single note work this provides improved results. For chordal work this should be set to off as the pitch tracker obviously cannot determine the pitch of simultaneous tones.
  • TRACK ADJ - This control allows fine-tuning the pitch shifter “splice length”. For large shifts this control can help improve the quality of the shifted note.


Octave divider

The Octave Divider creates two new notes one and two octaves below the input. This effect simulates the classic effect and works by actually turning the input into a square wave and then dividing the signal by two using flip-flops. Like the classic effect, this effect only works on single notes and works best on notes above the fifth fret. Experiment with pickup selection and effect placement to achieve the best results.

Parameters

  • LVL1,2 - Sets the volume level of the octaves.
  • PAN1,2 - Sets the panning of the octaves.
  • MIX - Sets the mix between the effect and input.


Crystals

The Crystals pitch shifter is similar to the Fixed Harmony but optimized for special effects. The effect works by chopping the audio up into little chunks and playing the chunks back (or "splicing" the chunks) at a different speed, thus allowing for interesting delay effects. The splice times in this effect are significantly longer than the times available in Fixed Harmony. It also features a reverse switch and extensive tempo options.

Parameters

  • MASTER PITCH - Multiplies the pitch shift by this amount. For example, if the shift is set to 12 semitones and the Master Pitch is 50%, the shift amount will be six semitiones.
  • MASTER FEEDBACK - Scales all the feedback amounts. You can attach a controller to this.
  • VOICE1,2 DETUNE - Sets the detune amount of the voice in cents. The range of +/- 50 cents. You can attach a controller to the detunes by pressing enter.
  • VOICE1,2 SHIFT - Sets the shift amount of the voice in half-steps. The range of shift is +/- 12 half-steps.
  • VOICE1,2 LEVEL - Sets the volume level of the voice.
  • VOICE1,2 PAN - Sets the panning of the voice.
  • VOICE1,2 DELAY - Sets the delay time of the voice in milliseconds.
  • VOICE1,2 DLYTEMPO - Locks the delay time to the global tempo. For example, if the global tempo is 120 bpm and the tempo is set to a quarter note (1/4) then the time will be 500 ms (one echo per beat). To ignore the global tempo set the tempo control to NONE.
  • VOICE1,2 SPLICE - Sets the splice time of the voice (or "size" of the spliced chunks) in milliseconds.
  • VOICE1,2 SPLTEMPO - Locks the splice time to the global tempo. For example, if the global tempo is 120 bpm and the tempo is set to a quarter note (1/4) then the time will be 500 ms (one echo per beat). To ignore the global tempo set the tempo control to NONE.
  • VOICE1,2 FEEDBACK - Sets the feedback of the voice to the input. By delaying and feeding a voice back strange pitch effects can be created as the note is translated pitch again and again.
  • DIRECTION - Sets the “direction” of the splice playback. Try setting to REVERSE for spacey effects.
  • FEEDBACK TYPE - Selects the type of feedback. DUAL sends the individual voices back to their respective delay lines. BOTH mixes the voices and sends them back to both delay lines. PING-PONG sends each voice to the opposite delay line.
  • HICUT FREQ - Sets the high-frequency rolloff of the pitched signal using a 12 dB / octave filter. This can be used to adjust the timbre of the voices.
  • CROSSFADE - Sets the amount of overlap in the audio snippets. A low setting will make the echoes more discrete whereas a high setting will tend to smear the echoes.
  • Important Note - The Crystals Algorithm was significantly change in frimware version 5 and beyond. To get pre 5.x patches to sound as intended do the following:

1. Set Master Feedback to 100%

2. Set splice times to half original value.

3. Set crossfade between 50-100%

Advanced whammy

[Ultra]

The Advanced Whammy mode is identical to the Classic Whammy mode except that the start and stop shift amounts are controllable in semitone increments. This allows you to set the heel down to any amount of shift and the toe down to any amount of shift rather than being constrained to pre- programmed intervals.

Parameters

The parameters for the Advanced Whammy are the same as the Classic with the following differences:

  • START - Sets the start pitch shift amount in semitones. This is the amount of pitch shift when the CTRL knob is in the minimum position.
  • STOP - Sets the stop pitch shift amount in semitones. This is the amount of pitch shift when the CTRL knob is in the maximum position.
  • FILTER - This can be used to adjust the timbre of the voices.


Arpeggiator

[Ultra]

The Arpeggiator is a 16-stage sequencer that controls the pitch shift. Complex arpeggio patterns can be created just by playing a single note.

Parameters

  • SCALE - Sets the type of scale (or scale mode) that the harmony will use. Examples are Ionian (major), Aeolian (minor), Whole Tone, etc. Set to CUSTOM to use custom scale tones (see Intelligent Harmony above for details).
  • KEY - Sets the key that the harmony will be in.
  • STAGES - Sets the number of stages in the pitch sequencer.
  • REPEATS - Sets the number of times the sequence will repeat once triggered. Set to INFINITE to loop forever.
  • RUN - When set to ON, the sequence starts. When set to OFF the sequence stops and resets to the beginning. Attach the envelope follower controller to this to retrigger the sequence on each new note.
  • TEMPO - Sets the tempo at which the sequencer steps.
  • GLIDE TIME - Sets the rate at which the harmony moves from the existing pitch to a new pitch.
  • MASTER LEVEL - Controls the overall level of all the sequence stages
  • AMPLITUDE SHAPE - Controls the shape of the output level as a function of the sequencer stage.
  • AMPLITUDE ALPHA - Controls the rate of change of the output level as a function of the sequencer stage.
  • MASTER PAN - Controls the overall level of all the sequence stages
  • PAN SHAPE - Controls the shape of the output panning as a function of the sequencer stage.
  • PAN ALPHA - Controls the rate of change of the panning as a function of the sequencer stage.
  • STAGE n SHIFT - Sets the amount of pitch shift for the selected stage of the sequence.

Custom Shifter

[Ultra]

The Custom Shifter is identical to the Intelligent Harmony except that it uses the custom shift tables stored in the global memory.

Parameters

All parameters are the same as the Intelligent Harmony mode with the following exceptions:

  • VOICE n SCALE - Selects the custom Global Scale to use. See the Global section for more details on Global Scales.


Auto Pitch

[Ultra]

The Auto Pitch mode corrects the pitch of the input. This can be used to correct vocal performances or as a special effect.

Parameters

All parameters for the Auto Pitch mode are described under the Intelligent Harmony mode.


Tips

When going direct, pitch shifting often sounds best when placed BEFORE the cab block.

The factory presets may have the block doing the shifting (pitch or multidelay) after the cabinet block. Try moving the pitch before the cabinet block for smoother results.

When you don't want to create a new patch for each change in Note, Scale, Voice1 and Voice2, it is possible to change these values by sending Sysex. When sending multiple sysex messages consecutively, it can happen than not all parameters are changed. Therefore it's best to put a delay between the consecutive messages.