Always consult the Owners Manuals and FAQs first.
FM3 information is being added as it becomes available, but it's preliminary and not final until release

Difference between revisions of "Pitch block"

From Axe-Fx II Wiki
Jump to: navigation, search
(Detune (micropitch))
(Pitch tracking: Poly or Mono)
Line 1,409: Line 1,409:
 
The Pitch Track setting impacts latency and the quality of tracking, depending on the input signal.
 
The Pitch Track setting impacts latency and the quality of tracking, depending on the input signal.
  
* '''Poly''' — works best for shifting chords
+
'''Poly''' — works best for shifting chords
* '''Mono''' — works best for shifting single notes
+
 
 +
'''Mono''' — works best for shifting single notes
  
 
<blockquote>"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." [http://forum.fractalaudio.com/threads/pitch-block-what-am-i-missing-latency-issue.144725/#post-1711906 source]</blockquote>
 
<blockquote>"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." [http://forum.fractalaudio.com/threads/pitch-block-what-am-i-missing-latency-issue.144725/#post-1711906 source]</blockquote>

Revision as of 08:05, 6 August 2019

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

Fixed Harmony / Dual Shift / Quad Shift

Firmware Ares replaces the Fixed Harmony mode on the Axe-Fx II with:

Dual Shift (2 voices)

Quad Shift (4 voices)

Note that Quad Shift doesn’t have Feedback parameters.

Ola Englund demonstrates pitch harmony with a pedal

Intelligent Harmony / Dual Harmony / Quad Harmony

Firmware Ares replaces the Intelligent Harmony mode on the Axe-Fx II with:

Dual Harmony (2 voices)

Quad Harmony (4 voices)

Octaver

The processors offer several ways to create an Octaver effect (octave down):

  • Pitch block: fixed shifted pitch, 1 octave down
  • Pitch block: Octave Divider type
  • Ring Modulator block in Tracking mode.

The results sound different. The Octave Divider sounds slightly like a synth, where a fixed harmony adds identical lower or higher harmony notes at fixed intervals. The Ring Modulator sounds vintage.

Detune (micropitch)

Pitch detuning is a great alternative to a chorus, without the "swirl" associated with 80's chorus tone. Use it in stereo for a very wide effect. Van Halen's sound on the Balance album is well-known example of stereo pitch detuning.

  1. Detune up and down the same amount, between +/-5 and +/-10
  2. Delay the voices for more width (i.e. 7 ms)
  3. Set mix at 25% or lower
  4. Put the block after the Amp block but before the stereo Cab block
  5. Pan the voices for a wide stereo effect

Try running a Chorus block before or after the Pitch block for a more intense effect.

Beware of Phase cancellation when running mono.

Firmware Ares has two Detune modes:

Dual Detune (2 voices)

Quad Detune (4 voices)

The Multitap Delay block in firmware Ares is also capable of multi-voice detuning.

Whammy

Use the Classic Whammy pitch type, and attach a pedal to the Control parameter.

Use Auto-Engage in the modifier menu to automatically engage the Pitch block.

You can engage a Whammy on the fly without using Auto-Engage ("Golden Whammy", M@'s idea, source):

  1. Put a Pitch block in line, set to Classic Whammy. Source: Global. Bypass Mode: Thru
  2. Assign the Control parameter to your pedal's external controller
  3. Assign the same external controller to the Mix parameter. Set Mix at zero. Modifier menu: Min 100, Max 0, Start 60.1, Mid 0, End 49.8, Slope 100, Scale 10, Offset -100
  4. Make sure the Pitch block is engaged and save the preset

Demo of the Whammy settings above

Increase the Scale parameter in the modifier menu to create some "flat" space at the top, so the octave arrives earlier and stays put.

Decrease the max frequency of the pitch-shifted voice to 5 kHz or lower to make it less "digital" and less thin.

(about the original Whammy pedal) "I would venture to guess that the pedal sample rate is low, like maybe 11 kHz. This limits the frequency response to 5K. Higher sampling rates mean more processing power which means more expensive DSP. These things were designed to be inexpensive." source

Drop-tuning and virtual capo

AX8, FX8 and Axe-Fx II:

  1. Put a Pitch block in series at the start of the grid
  2. Set it to Fixed Harmony
  3. For a drop of two semitones set one voice to -2
  4. Set the other voice's Level to -80 to mute it
  5. Set Mix to 100%, Tracking to On, Pitch Track to Poly

You can also use the Advanced Whammy mode in the Pitch block. Sounds and works the same but a little easier to to configure.

If you can't stand the latency:

Note that there will always be some latency.

Axe-Fx III:

Use the Virtual Capo mode in the Pitch block (firmware Ares) for drop-tuning as well as virtual capo.

"This is a simple one-voice pitch shift that is intended for drop-tuning and virtual capo use and is easy to configure and use."

Dive bomb

To simulate an automated "dive bomb" pitch effect:

  1. Create a preset with a Pitch block
  2. Set Pitch mode to Classic Whammy, Up|Dn 2 Oct., Pitch Track: off, 100% mix
  3. Enter the Modifier menu of the Control parameter in the Pitch block. Set Source to one of the externals. Set Damping to 750, for starters
  4. Enter the Modifier menu of the Bypass parameter in the Pitch block. Set Source to the same external controller as above

On the foot controller:

  1. Program a switch to send the external controller's CC
  2. The switch can be latching or momentary, whatever works for you

To operate: select the preset. Press the switch (press and hold if it's a momentary switch) for the effect to kick in. Press again (or release) to stop, and bypass the Pitch block.

You can also use your expression pedal instead of a switch. Use the corresponding external controller.

Instead of a switch, you can also use Auto-Engage.

You can adjust the length of the dive through the Damping parameter, use another Whammy mode, make it even more dramatic by adding a Flanger, etc.

Bakerman's tip to dive deeper than two octaves: select "Whole Tone" for Harmony. In the modifier menu set Minimum to 1, and Maximum to the desired drop (try -19). Increase Glide to get rid of the steps.

Crystal Echoes

Smoothen the Crystal Echoes effect by fading in the effect: assign the Envelope Controller to the Input Gain parameter.

Multiple harmonies

Bakerman explains how to generate 5 harmonies with one guitar and one Axe-Fx II preset (Hotel California)

Simulate a 12-string guitar

To simulate a 12-string guitar:

  1. Put the Pitch block between the Amp and Cab blocks
  2. Select the Fixed Harmony or Dual Harmony type
  3. Set Tracking Mode to Poly
  4. Shift one or both voices to +12
  5. Increase Detune a little to add realism
  6. Set Mix between 20% and 30%

This of course isn't a true simulation, because on a real 12-string the bottom four strings are doubled a full octave higher, and the two highest strings are doubled (same octave). But it works well.

Custom scales

The "Custom" Pitch type uses the values on the Custom Scales page in the Global menu.

It's important to understand how Custom Scales work. You must (temporarily) transpose the part to the key of A, and program the custom scales based on that key. After having done that, enter the correct key for the part in the parameter field.

More explanation

AustinBuddy's tutorial

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 usage 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".

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