Axe-Fx III Firmware 29.01 Public Beta #2 (Beta 4)

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Thank you very much for this beta.

The virtual capo sounds much better with fewer artifacts than before.

@Admin M@ , I don't think it's due to this latest firmware, but while browsing the "deluxe tweed" amp, I noticed something that seems abnormal (maybe a bug?).
The "normal gain" knob doesn't seem to work while rotating it, and at the maximum position (10), the preamp gain seems to cut off almost completely.
 
Some added VC testing below for this release (Tracking at 5, Individual notes played in Notes Mode, Arpeggios/Chord in Chord Mode - DI + Test preset attached here). Also showing the results (from same DI) for the previous 2 releases.

VC -3 (Mix at 100%) - FW29.01b4


VC -3 (Mix at 100%) - FW29.01b1


VC -3 (Mix at 100%) - FW29.00


VC Off (Mix at 0%) - FW29.01b4
 
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ohyep said:
Is there no way at all to lower the latency even further? Like absolutely not possible?

Just kinda a tech/cpu/software related question . Not a request or anything.
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Latency for what exactly?

If it's something related to the pitch of the guitar it's very unlikely anything can be done about it because of physics. It takes time to determine the note being played, and the lower the note the longer it takes to ensure accuracy.

Cliff talks about it in many places in the forum and his comments are collected in the Wiki. Here's a couple…
[11] Pitch shifting necessarily has latency. You need a history buffer big enough to contain at least one period at the lowest frequency you want to be able to shift. 19ms isn't bad and corresponds to about 53 Hz. Probably actually around 60 Hz as some of that latency is A/D and D/A conversion time and frame buffering.

If you want a "polyphonic shifter" you need a buffer that is large enough to hold an entire "period" of the waveform. This period, which we define as the maximum autocorrelation time, may be much greater than the period of the lowest note played. I.e., if you play an open E chord the period will usually be much less than 1/82. Some chord shapes result in very long periods, particularly those with dissonant intervals, e.g. major 7.

The shorter the buffer the less latency but the more tremolo effect will be introduced due to imperfect correlation at the splice point. The longer the buffer the less tremolo effect but the greater the latency.
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[14] 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).
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Faster CPUs or code won't help because it still takes time for the string to vibrate enough times to find the pitch.
 
I use the VC on a few songs during the night so I couldn't help but download this FW. Have a show on Saturday that I planned on using the FM3 for but probably will take the Axe-Fx now (actually I'll probably take both).

Anyway - I updated and was playing my presets that use the VC and was getting a lot of volume fluctuation just while playing straight chords - the Pitch block was between the amp and the cab (I've seen multiple opinions on where to put it and I guess I went with that one) - when I moved it out to right after Input 1, things got dramatically better! No volume fluctuations and it feels tighter than it did before. I didn't feel or perceive the latency that I felt before which is awesome! Thanks Cliff.
 
I've always thought of these pitch shifter artefacts as cool glitch effects. But I like guitar hum and amp hiss.
I mean listen to the opening of "Poundcake" by Van Halen. Noisy as hell. I love it.
 
Brian Coonan said:
I use the VC on a few songs during the night so I couldn't help but download this FW. Have a show on Saturday that I planned on using the FM3 for but probably will take the Axe-Fx now (actually I'll probably take both).

Anyway - I updated and was playing my presets that use the VC and was getting a lot of volume fluctuation just while playing straight chords - the Pitch block was between the amp and the cab (I've seen multiple opinions on where to put it and I guess I went with that one) - when I moved it out to right after Input 1, things got dramatically better! No volume fluctuations and it feels tighter than it did before. I didn't feel or perceive the latency that I felt before which is awesome! Thanks Cliff.
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Yes, the correct location would be right after the Input block.
 
FractalAudio said:
Yes, the correct location would be right after the Input block.
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I often wonder how many people don’t know this and therefore have a lesser opinion of pitch shifters as a whole, regardless of device…

Out of curiosity, what are the odds (if it’s even possible) of splitting the Virtual Capo off into its own block, completely separate from the Pitch Block? If that were to happen, would users of the FM3 still only be able to use one or the other or would that enable one VC and one Pitch block? Just curious.
 
AlbertA said:
Adding to the my small test described here: https://forum.fractalaudio.com/thre...-29-01-public-beta.214695/page-7#post-2696458

TLDR, Virtual capo set at -2, set to Chords and tracking at 5.
  1. v26.01 Pitch block disabled
  2. DI downshifted by Apple's AUNewPitch plugin but processed by the same Axe-Fx III chain. Latency ~80ms.
  3. v26.01, -2 capo enabled, smooth pitch tracking - latency ~25ms
  4. v27.00, -2 capo enabled, chords pitch tracking - latency ~30ms
  5. v29.00, -2 capo enabled, chords pitch tracking - latency ~25ms
  6. v29.01 beta 2, -2 capo enabled, chords pitch tracking - latency ~25ms
  7. v29.04 beta 4, -2 capo enabled, chords pitch tracking - latency ~25ms
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Apple still sounds most artifact free.
I wonder if Fractal could add a super long processing option for rendering only.
 
Ugly Bunny said:
I often wonder how many people don’t know this and therefore have a lesser opinion of pitch shifters as a whole, regardless of device…
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Location is more dependent on how the Pitch block is being used.

For the VC, it makes sense first in the chain. For other types that may not be optimal.
 
jimmynorrisjr said:
I thought the drive block had to be first if you are taking advantage of the auto input impedance like in some vintage fuzz types?
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No... The auto impedance is based on the first active block after the Input block and on the same row (or a row below).

You can move the blocks up or down while still keeping a serial signal path.
 
So I have to move the pitch block 2 rows down in order for it to be active and still allow the drive to auto adj the input impedance? fudge
 
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