Intonation with Axe tuner: Why doesn't it work?

It also matters whether you are using one of the tuners on the unit or the one on the FC. The display on the FC isn’t as accurate/detailed.

Personally, I kept my old Turbo Tuner to use on stage. (Also frees up a button on the FC, which is a plus.)
 
I was thinking about this more. Is it possible the OP has the wrong setting for the line power frequency? Could that cause the issue?
 
It also matters whether you are using one of the tuners on the unit or the one on the FC. The display on the FC isn’t as accurate/detailed.
I’m interested in hearing the logic behind this since the FC does no processing and is only a client to the information being sent from the unit itself.
 
Could this be related to the Railsback curve? I’ve tuned a few pianos, and an octave away is rarely exact double or half a frequency. Maybe this is that?
Thanks
Pauly

I've compared the Axe-Fx III tuner to some other tuners, and setting the intonation of a guitar with the Axe doesn't work. The high octave on any given string (open string to the 12th fret, or fretted like the 3rd to 15th fret), always reads as sharper than it really is. The intonation can be dead on with my Korg DT-7 and Sonic Research ST-200, and the Axe still shows the octaves to be quite sharp.

It's kinda weird, because tuning to the open strings works fine. But tuning to the 12th fret harmonics will give you a guitar that is flat across the range (since they read too sharp on the Axe tuner).
 
I think it’s just that the FC displays larger steps with less granularity
And that makes it less accurate? Have you tested this?

I checked it against my TC-Polytune Clip (±0.02 cents) and Peterson Stroboclip HD (±0.1 cents), and the tuner display on the FC-12 connected to the FX3 agreed with them.

The size of the pixels that make up the blocks means little. The important thing is if we can tell the note is flat or sharp, if it's approaching being in tune, and how the tuner indicates when the note is in tune, which the FC display does nicely. When you get the >Φ< indicator you're in tune, or so close it's difficult to hear the difference. I'd gladly work with the FC tuner display over using a Snark or many other pedals I've had over the years that indicated they were in tune but were actually off.
 
IIRC, I think Cliff said somewhere that the needle tuner uses a pitch average of the whole signal, while the strobe tuner uses only the fundamental of the note. If the upper harmonics of the string are skewed one way or the other compared to the fundamental, you can get different results between the two tuners. If you turn your tone control all the way down on your guitar, you'll probably see less of a difference between them since that rolls off much of the upper harmonics and leaves you with closer to a sine wave.

I read somewhere many moons ago to not use harmonics to tune or intonate, but rather use open strings and fretted 12th since the harmonics can sometimes be a bit off depending on how you hit them and the particular strings on the guitar. No guitar will ever intonate perfectly, so it's always been one of those "close enough for rock and roll" things for me. Hell die hard Tele snobs claim that the vintage 3 saddle design's inability to intonate well is a key part of the Tele's character. I'll take a more modern compensated version any day personally.
 
Last edited:
IIRC, I think Cliff said somewhere that the needle tuner uses a pitch average of the whole signal, while the strobe tuner uses only the fundamental of the note. If the upper harmonics of the string are skewed one way or the other compared to the fundamental, you can get different results between the two tuners. If you turn your tone control all the way down on your guitar, you'll probably see less of a difference between them since that rolls off much of the upper harmonics and leaves you with closer to a sine wave.

I read somewhere many moons ago to not use harmonics to tune or intonate, but rather use open strings and fretted 12th since the harmonics can sometimes be a bit off depending on how you hit them and the particular strings on the guitar. No guitar will ever intonate perfectly, so it's always been one of those "close enough for rock and roll" things for me. Hell die hard Tele snobs claim that the vintage 3 saddle design's inability to intonate well is a key part of the Tele's character. I'll take a more modern compensated version any day personally.
https://wiki.fractalaudio.com/wiki/index.php?title=Tuner#Tuner_types
 
IIRC, I think Cliff said somewhere that the needle tuner uses a pitch average of the whole signal, while the strobe tuner uses only the fundamental of the note. If the upper harmonics of the string are skewed one way or the other compared to the fundamental, you can get different results between the two tuners. If you turn your tone control all the way down on your guitar, you'll probably see less of a difference between them since that rolls off much of the upper harmonics and leaves you with closer to a sine wave.

I read somewhere many moons ago to not use harmonics to tune or intonate, but rather use open strings and fretted 12th since the harmonics can sometimes be a bit off depending on how you hit them and the particular strings on the guitar. No guitar will ever intonate perfectly, so it's always been one of those "close enough for rock and roll" things for me. Hell die hard Tele snobs claim that the vintage 3 saddle design's inability to intonate well is a key part of the Tele's character. I'll take a more modern compensated version any day personally.
See a few posts above:

https://forum.fractalaudio.com/thre...-tuner-why-doesnt-it-work.179794/post-2195350
 
As I wrote, only the needle tuner. I've confirmed it with test tones. The needle tuner will get sharp on high notes when no other tuner does it (even the Axes own strobe tuner). From G4-G5 it's pretty much exactly 5 cents sharp.
The needle tuner is more likely to be idiosyncratic than the strobe tuner. In other words, it's not too surprising that you see this while others don't, or that it might only occur with some guitars, or that it may differ from other tuners. I'm quite certain if you use a sine wave for a test tone, you won't see the discrepancy. In any case, the strobe tuner is often the better choice to use for intonation adjustments, and it sounds like that's especially true in your particular situation.
 
Last edited:
The zero-crossing tuner (the needle tuner) is more likely to be idiosyncratic than the correlation tuner (the strobe tuner). In other words, it's not too surprising that you see this while others don't, or that it might only occur with some guitars, or that it may differ from other tuners. I'm quite certain if you use a sine wave for a test tone, you won't see the discrepancy. In any case, the strobe tuner is often the better choice to use for intonation adjustments, and it sounds like that's especially true in your particular situation.
I did in fact use a sine wave to confirm that the needle tuner is sharp on high notes 😉 Interesting that my other non strobe tuners don't display this behaviour though.
 
The zero-crossing tuner (the needle tuner) is more likely to be idiosyncratic than the correlation tuner (the strobe tuner). In other words, it's not too surprising that you see this while others don't, or that it might only occur with some guitars, or that it may differ from other tuners. I'm quite certain if you use a sine wave for a test tone, you won't see the discrepancy. In any case, the strobe tuner is often the better choice to use for intonation adjustments, and it sounds like that's especially true in your particular situation.
The needle is a correlation tuner. The strobe tuner downconverts the signal to baseband and then displays the I/Q vectors as a strobe tuner simulation. Zero-crossing tuners are inaccurate.

If your strings are old the needle tuner will differ from the strobe tuner because the strobe tuner only displays the fundamental. When your strings get old the harmonics become out-of-tune with the fundamental.
 
I did in fact use a sine wave to confirm that the needle tuner is sharp on high notes 😉 Interesting that my other non strobe tuners don't display this behaviour though.
Interesting, yes. Anyway, my advice remains the same: use the strobe tuner for intonation adjustments. My experience (sorry that I misspoke about which is the correlation tuner) matches what Cliff is saying: that tuner will be less susceptible to physical artifacts of the string.
 
And that makes it less accurate? Have you tested this?

I checked it against my TC-Polytune Clip (±0.02 cents) and Peterson Stroboclip HD (±0.1 cents), and the tuner display on the FC-12 connected to the FX3 agreed with them.

The size of the pixels that make up the blocks means little. The important thing is if we can tell the note is flat or sharp, if it's approaching being in tune, and how the tuner indicates when the note is in tune, which the FC display does nicely. When you get the >Φ< indicator you're in tune, or so close it's difficult to hear the difference. I'd gladly work with the FC tuner display over using a Snark or many other pedals I've had over the years that indicated they were in tune but were actually off.
For general tuning, yes the FC display is close enough for rock and roll. However, the OP was asking about intonation, and the extra granularity is definitely needed there. FC can say it is in tune while on the main unit, you can see it is slightly sharp/flat but close.
 
When your strings get old the harmonics become out-of-tune with the fundamental.
I'm interested to know how/why this is; and is this an effect of strings getting old or is this what causes us to perceive strings as old? Does this have anything to do with why old strings don't stay in tune well?
 
I wonder how musicians got through the 'Mozart' era with no visual aid.
Until the 19th century, notes were not considered to have a fixed pitch. We basically did the tuning of the instruments according to the material context. For example, an organ served as a reference for the instruments that were close to it ... You could also choose your pitch to make singers more comfortable or simply to satisfy your taste ... The variations in pitch were impressive for our ears accustomed to an LA steadfastly fixed at around 440hz for almost a century. We now know that LA varied by about a fourth depending on the time, place and style of music played. Because as incredible as it may seem, until the 18th century, we often saw two tuning forks: the Church tuning fork and the Chamber tuning fork ... Nowadays, to assess the pitch of a historical tuning fork, one usually takes as a reference an instrument of the time, for example a Grenser flute. If we measure our pitch at 15 ° C, and we get a result of 430hz, we can just deduce that the music was played between 427hz and 434hz depending on whether it was more or less cold.
 
And don’t forget that they own tuning forks. I use a tuning fork all my first years and it’s probably because of this that I develop my ears . I use tuners as a mute in general and really when I record something important like an album or … sometimes using just a tuner, your guitar is not in tune while playing chords even if it’s well set

Didn’t know that strobe tuners are more accurate @FractalAudio
 
  • Like
Reactions: ESW
Back
Top Bottom