Pitch block

Available on which products

• Axe-Fx III: 2 blocks
• FM3: 1 block
• Axe-Fx II: 2 blocks
• AX8: 1 block
• FX8: 1 block

Channels or X/Y switching

• Axe-Fx III and FM3: 2 channels
• Axe-Fx II: X/Y
• AX8: X/Y
• FX8: X/Y

Pitch types and effects

The Pitch block in the Axe-Fx 3 and FM3 has its own pitch detector, separate from the internal Pitch controller. Pitch detection is improved in the Axe-Fx III and FM3, and the number of voices has been increased to 4.

(FM3) "Pitch block functionality will be identical. The only potential differences may relate to pitch detection since that functionality is actually outside of the Pitch block and is still being ironed out." source

Pitch types in the Axe-Fx III and FM3 are:

• Dual Detune
• Quad Detune
• Dual Shift
• Quad Shift
• Dual Harmony
• Quad Harmony
• Classic Whammy
• Octave Divider
• Crystal Echoes
• Advanced Whammy
• Arpeggiator
• Custom Shifter
• Quad Shift Delay
• Quad Harmony Delay
• Virtual Capo

Position of the Pitch block on the grid

If you want to add harmonies to your main signal, put the Pitch block between the Amp and Cab block for best results. Alternatively (Axe-Fx only), split the signal into two rows before the Amp block, and put Pitch and a 2nd Amp block in the other row.

If you want to shift the entire amp signal (100% wet), e.g. to simulate a down-tuned guitar or capo, put Pitch before the Amp block.

"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 Cab block. Try moving the pitch before the Cab for smoother results."

"The pitch block basically shifts the entire cab freq. response up/down if it's after cab. A slight detune might sound about the same either way but with a half step, whole step, etc. the difference becomes more apparent." (Bakerman)

Pitch shifting, CPU and latency

The Pitch block in the AX8 and FX8 is very sensitive to CPU usage, even far before the limit is reached. When using the Whammy mode for example, try to keep CPU usage below 60%. Some Pitch types in the AX8 and FX8 provide an Economy mode, which offers comparable audio performance but uses less CPU.

"Once the CPU usage crosses a certain threshold (which could happen if you are streaming audio) the pitch detection will slow down as the global pitch detector necessarily has a lower priority than the primary audio processing. If you change the Pitch Source to Local then the local pitch detector runs at the same priority as the audio." source

"Pitch detection has a lower priority than audio processing. If CPU usage is very high the pitch detectors won't run often". source

"The better the pitch shifting, the more the latency. It's a perceptual process. There is no mathematically perfect way to do it. Also, when you pitch shift, the sound coming from the speakers doesn't reinforce the strings (since it's at a different frequency) so you don't get sustain and feedback harmonics." source

"A low E has a period of about 12 ms. This means you have to buffer at least 12 ms to shift anything from low E and up. To also work with bass then low E is 24 ms."

"Pitch shifting necessarily adds latency. Pitch shifting is a perceptual process. It requires a reasonable amount of history to work. This adds latency. Typically 20ms and up. Some people are more tolerant to latency than others. I've compared the latency of our algorithm to other products and ours is equal or better but there is latency in any pitch shifter. All pitch shifters have tradeoffs. The lower the latency the more prone they are to tremolo artifacts, double transients and other issues. Solving those issues increases the latency and the computational burden. The only pitch shifting algorithm that has negligible latency is the "Rollers" algorithm but that requires insane amounts of CPU and the samples I've heard aren't impressive. It also has its share of issues (smearing, chirping)." source

"Pitch detection is a difficult problem. Polyphonic pitch detection is orders of magnitude more difficult. Real-time pitch detection is much more difficult than non-real-time. Polyphonic real-time pitch detection is nearly impossible." source

"To do polyphonic pitch shifting well you need around 50 ms of history. So nominally the delay will be half that, 25 ms." source

Learn mode

The Pitch block has a Learn function. Turn it on, play a note and hold it, and the device will set the key according to the note you played.

In firmware Ares, the Pitch block doesn't have be engaged to be able to use Learn.

Parameters

The parameters are also explained in the Owner's Manual.

Parameters table (per type)

DUAL DETUNE	Axe-Fx III	Axe-Fx II	AX8 / FX8
Input Mode	yes
Detune 1,2	yes
Delay Time 1,2	yes
Level 1,2	yes
Pan 1,2	yes
LFO Rate, Tempo, Depth	yes
Low Cut, High Cut	yes
Input Gain	yes

QUAD DETUNE	Axe-Fx III	Axe-Fx II	AX8 / FX8
Input Mode	yes
Feedback Mode	yes
Detune 1,2,3,4	yes
Delay Time 1,2,3,4	yes
Delay Tempo 1,2,3,4	yes
Feedback 1,2,3,4	yes
Level 1,2,3,4	yes
Pan 1,2,3,4	yes
LFO Rate, Tempo, Depth	yes
Low Cut, High Cut	yes
Input Gain	yes

DUAL SHIFT	Axe-Fx III	Axe-Fx II	AX8 / FX8
Master Pitch	yes
Master Delay	yes
Master Feedback	yes
Master Pan	yes
Master Level	yes
Shift 1,2	yes
Detune 1,2	yes
Detector Source	yes
Tracking Mode	yes
Tracking	yes
Temperament	yes
LFO Rate, Tempo, Depth	yes
Delay 1,2	yes
Delay Tempo 1,2	yes
Feedback 1,2	yes
Input Mode	yes
Level 1,2	yes
Pan 1,2	yes
Low Cut, High Cut	yes
Input Gain	yes

QUAD SHIFT	Axe-Fx III	Axe-Fx II	AX8 / FX8
Master Pitch	yes
Master Delay	yes
Master Pan	yes
Master Level	yes
Shift 1,2,3,4	yes
Detune 1,2,3,4	yes
Detector Source	yes
Tracking Mode	yes
Tracking	yes
Temperament	yes
LFO Rate, Tempo, Depth	yes
Delay 1,2,3,4	yes
Delay Tempo 1,2,3,4	yes
Input Mode	yes
Level 1,2,3,4	yes
Pan 1,2,3,4	yes
Low Cut, High Cut	yes
Input Gain	yes

DUAL / QUAD HARMONY	Axe-Fx III	Axe-Fx II	AX8 / FX8
Master Delay	yes
Master Pan	yes
Master Level	yes
Key	yes
Learn	yes
Scale	yes
Harmony 1,2 (3,4)	yes
Detune 1,2 (3,4)	yes
Temperament	yes
LFO Rate, Tempo, Depth	yes
Delay 1,2 (3,4)	yes
Delay Tempo 1,2 (3,4)	yes
Level 1,2 (3,4)	yes
Pan 1,2 (3,4)	yes
Input Gain	yes
Low Cut, High Cut	yes
Detector Source	yes
Tracking	yes
Pitch Quantize	yes
Glide Time	yes
Custom Scale — Number of Notes	yes
Custom Scale — Tonic	yes
Custom Scale — Note 2-8	yes

WHAMMY	Axe-Fx III	Axe-Fx II	AX8 / FX8
Whammy Mode	yes
Whammy Control	yes
Detector Source	yes
Tracking Mode	yes
Tracking	yes
Input Gain	yes
Low Cut, High Cut	yes

OCTAVE DIVIDER	Axe-Fx III	Axe-Fx II	AX8 / FX8
Detector Source	yes
Input Gain	yes
Low Cut, High Cut (not operational)	yes
Level 1,2	yes
Pan 1,2	yes

CRYSTAL ECHOES	Axe-Fx III	Axe-Fx II	AX8 / FX8
Master Pitch	yes
Master Feedback	yes
Master Pan	yes
Master Level	yes
Shift 1,2	yes
Detune 1,2	yes
Temperament	yes
Crossfade Time	yes
Crossfade Type	yes
Splice Time 1,2	yes
Splice Tempo 1,2	yes
Direction	yes
Delay 1,2	yes
Delay Tempo 1,2	yes
Feedback 1,2	yes
Feedback Type	yes
Level 1,2	yes
Pan 1,2	yes
Input Gain	yes
Low Cut, High Cut	yes

ADVANCED WHAMMY	Axe-Fx III	Axe-Fx II	AX8 / FX8
Start Shift	yes
Stop Shift	yes
Whammy Control	yes
Detector Source	yes
Tracking Mode	yes
Tracking	yes
Input Gain	yes
Low Cut, High Cut	yes

ARPEGGIATOR	Axe-Fx III	Axe-Fx II	AX8 / FX8
Arpeggiator Run	yes
Master Level	yes
Master Pan	yes
Key	yes
Scale	yes
Temperament	yes
Detector Source	yes
Tracking	yes
Arpeggiator Steps	yes
Arpeggiator Repeats	yes
Arpeggiator Tempo	yes
Glide Time	yes
Amplitude Shape	yes
Amplitude Alpha	yes
Pan Shape	yes
Pan Alpha	yes
Step 1-16 Shift	yes
Custom Scale — Number of Notes	yes
Custom Scale — Tonic	yes
Custom Scale — Note 2-8	yes
Input Gain	yes
Low Cut, High Cut	yes

CUSTOM SHIFTER	Axe-Fx III	Axe-Fx II	AX8 / FX8
Master Delay	yes
Master Pan	yes
Master Level	yes
Key	yes
Learn	yes
Tracking	yes
Glide Time	yes
Temperament	yes
Scale 1,2	yes
Detune 1,2	yes
Level 1,2	yes
Pan 1,2	yes
Delay 1,2	yes
Delay Tempo 1,2	yes
Detector Source	yes
Input Gain	yes
Low Cut, High Cut	yes

QUAD SHIFT DELAY	Axe-Fx III	Axe-Fx II	AX8 / FX8
Master Pitch	yes
Master Delay	yes
Master Feedback	yes
Master Pan	yes
Master Level	yes
Shift 1,2,3,4	yes
Detune 1,2,3,4	yes
Detector Source	yes
Tracking Mode	yes
Tracking	yes
Temperament	yes
LFO Rate, Tempo, Depth	yes
Delay 1,2,3,4	yes
Delay Tempo 1,2,3,4	yes
Feedback 1,2,3,4	yes
Input Mode	yes
Level 1,2,3,4	yes
Pan 1,2,3,4	yes
Low Cut, High Cut	yes
Input Gain	yes

QUAD HARMONY DELAY	Axe-Fx III	Axe-Fx II	AX8 / FX8
Master Delay	yes
Master Feedback	yes
Master Pan	yes
Master Level	yes
Key	yes
Learn	yes
Scale	yes
Harmony 1,2,3,4	yes
Detune 1,2,3,4	yes
Temperament	yes
LFO Rate, Tempo, Depth	yes
Delay 1,2,3,4	yes
Delay Tempo 1,2,3,4	yes
Feedback 1,2,3,4	yes
Level 1,2,3,4	yes
Pan 1,2,3,4	yes
Input Mode	yes
Input Gain	yes
Low Cut, High Cut	yes
Detector Source	yes
Tracking	yes
Pitch Quantize	yes
Glide Time	yes
Custom Scale — Number of Notes	yes
Custom Scale — Tonic	yes
Custom Scale — Note 2-8	yes

VIRTUAL CAPO	Axe-Fx III	Axe-Fx II	AX8 / FX8
Shift	yes
Detune	yes
Detector Source	yes
Tracking Mode	yes
Tracking	yes
Input Gain	yes
Low Cut, High Cut	yes

Pitch tracking: Poly or Mono

The Pitch Track setting impacts latency and the quality of tracking, depending on the input signal.

• Poly — works best for shifting chords
• Mono — works best for shifting single notes

"If you set the Tracking to Mono there will be less latency. For small shifts (up/down a few semitones) there is no discernible difference between mono and poly. Even for large shifts mono works well now whereas before it didn't track chords well." source

"To do polyphonic pitch shifting well you need around 50 ms of history. So nominally the delay will be half that, 25 ms. If you set the detector to Mono the latency will be less but it won't track chords, especially complex ones, as well due to lack of correlation in the history buffer." source

Pitch source: Global or Local

This parameter determines which signal the Pitch block uses for tracking.

Axe-Fx II, AX8, FX8:

• Global (default) — the signal at the input of the grid (pitch controller) is used to track the pitch. This will usually suffice, unless there are specific demands or when the CPU load is high (see below)

• Local — the signal at the input of the Pitch block on the grid is used to track the pitch. Use this when you need accurate and fast pitch detection in high-CPU usage presets

Axe-Fx III and FM3:

Pitch in the Axe-Fx III uses its own pitch detector, separate from the Internal Controllers. Choose between "Block" (equivalent of "Local", see above) and "Input x".

Voice: Feedback

This is placed before the Voice Level parameter. So when Feedback is turned up and Level is turned down, you'll still hear repeats.

Low Cut, High Cut

These parameters are present in every Pitch type. However, they are not operational in the Octave Divider.

Temperament

This parameter has been added in firmware Ares.

• Just — ratios are defined by the harmonic overtone series
• Equal (default) — sweeter harmony, especially when followed by distortion

For a demonstration of the difference between the two settings, try factory preset "Lazy Man's Arpeggio" and switch the parameter between the two settings.

More information

Harmony scales

The Owner's Manual explains the different harmony scales.

Wikipedia

Pitch shifting in Wikipedia