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

guitarnerdswe said:
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).
Click to expand...
I just tried 3 different guitars and the Axe-FX tuner shows the first harmonic is consistent with the open string on all three. Exactly how much sharp is it reading for you?
 
I recently intonated a guitar with an evertune bridge on my axe 3. Harmonics easy and with the pressure I apply while real time playing on 12th fret I had absolutely no issue adjusting the guitar.
 
When tuning, for intonation or performance, the guitar should be on the neck pickup and the tone control rolled off to supply the fundamental tone with few harmonics. The harmonics can throw off a tuner.

And, anyone who wants to make themselves crazy, it seems we can use the tuner’s “tuning-fork” mode to send a signal into the modeler and see if they agree on the pitch. Then reverse the order and use the SYNTH block to send a signal to the tuner and see what it says. Finally send the FX3’s SYNTH output from OUT 2 into INPUT 1, and engage the tuner and see if the FX3 agrees with itself. Then meet in a back alley at midnight and be prepared to discuss the results.
 
Last edited:
I’ve used my Peterson Strobes and their clip-on, my FX3, TC Polytune and their clip-on, and had good results with all when intonating my guitars.

Once we’re using a tuner that’s measuring in the hundredths of cents, +/-0.02 cents for the Polytune, and tenths for +/-0.1 cent for Peterson’s we should be plenty good-enough. Because the modeler requires extreme accuracy I suspect it’s as low as TC’s and Peterson’s ability to resolve pitch, though the specs don’t say. And, once we’re into that accuracy I find it hard to not have finger pressure cause the pitch to waver when using any of them. In the middle of a song I can’t hear that accuracy or when it’s off a tiny amount.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3427364/ is an interesting paper that I’m puzzling through regarding people’s ability to recognize differences in pitch. In western music we’re predisposed to semitone-based music and most easily recognize differences in that range. I wonder what people who regularly work with microtones would say about the FX3’s tuner and pitch accuracy.
 
Last edited:
Intonation is a player specific operation.

I fail to see, how we can trust a tuner in one function and not another. If the harmonic above the 12th fret is in tune, and you mash the 12th fret how you usually mash it is pretty close, then intonation is good.

If you're looking at fractions of a cent, then you are either a super-player or nutty.

I have a Korg DT-Pro that I trusted for decades. It's on right now. It's no more accurate than the Axe-Fx3 tuner.
 
I guess this thread could be an excuse to put one of those cool looking pitch black tuners in my rack. 😂
Plenty of room in there since I bought an Axefx3 and sold EVERYTHING else.
🤘😜
 
Greg Ferguson said:
When tuning, for intonation or performance, the guitar should be on the neck pickup and the tone control rolled off to supply the fundamental tone with few harmonics. The harmonics can throw off a tuner.

And, anyone who wants to make themselves crazy, it seems we can use the tuner’s “tuning-fork” mode to send a signal into the modeler and see if they agree on the pitch. Then reverse the order and use the SYNTH block to send a signal to the tuner and see what it says. Finally send the FX3’s SYNTH output from OUT 2 into INPUT 1, and engage the tuner and see if the FX3 agrees with itself. Then meet in a back alley at midnight and be prepared to discuss the results.
Click to expand...

I actually did the test tone thing, both using the Axe synth block and Reapers. Thanks for the tip! It did provide some useful information.

GlennO said:
I just tried 3 different guitars and the Axe-FX tuner shows the first harmonic is consistent with the open string on all three. Exactly how much sharp is it reading for you?
Click to expand...

I've concluded that it's the "needle" tuner on the Axe that is off (especially fretted and high pitches). For instance, intonating 3rd to 15th fret on the high e is about 5 cents sharp compared to all my other tuners. That's noticeable for sure.
 
guitarnerdswe said:
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).
Click to expand...
guitarnerdswe said:
I've concluded that it's the "needle" tuner on the Axe that is off (especially fretted and high pitches). For instance, intonating 3rd to 15th fret on the high e is about 5 cents sharp compared to all my other tuners. That's noticeable for sure.
Click to expand...
Just to be clear, you're saying the harmonic at the 12th fret reads 5 cents sharp when the open string is dead on? I'm definitely not seeing that. Have you tried different guitars to see if it's specific to one guitar?

And this is with both tuners on the Axe-FX? I can see how the correlation tuner might conceivably have an error specific to a frequency range, but the zero-crossing tuner shouldn't be susceptible to that kind of a problem.
 
guitarnerdswe said:
I've concluded that it's the "needle" tuner on the Axe that is off (especially fretted and high pitches). For instance, intonating 3rd to 15th fret on the high e is about 5 cents sharp compared to all my other tuners. That's noticeable for sure.
Click to expand...
Old strings or bad batch for some reason? Some years ago, I experienced some "disagreement" between the two tuners. New strings solved it.
 
GlennO said:
Just to be clear, you're saying the harmonic at the 12th fret reads 5 cents sharp when the open string is dead on? I'm definitely not seeing that. Have you tried different guitars to see if it's specific to one guitar?

And this is with both tuners on the Axe-FX? I can see how the correlation tuner might conceivably have an error specific to a frequency range, but the zero-crossing tuner shouldn't be susceptible to that kind of a problem.
Click to expand...

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.

GiRa said:
Old strings or bad batch for some reason? Some years ago, I experienced some "disagreement" between the two tuners. New strings solved it.
Click to expand...

Not a guitar issue. I've noticed this for quite some time, rechecking every time I put new strings own. Generating test tones removed the possibility of it being a guitar issue.
 
GiRa said:
Old strings or bad batch for some reason? Some years ago, I experienced some "disagreement" between the two tuners. New strings solved it.
Click to expand...
My experiences agree with this. When there's tuner weirdness, a funky string or a fret that's just a hair too high is usually the culprit.
 
The Axe is best suited for intonation setups. Precondition that said guitar is generally setup correct (action, saddle, strings, neck relief ...).
A guitar is far from perfect what fret board layout is concerned, therefore some tempering of the intonation may be necessary to get things harmonically balanced across the board.
I’m anal about intonation!
 
Solarfire said:
The Axe is best suited for intonation setups. Precondition that said guitar is generally setup correct (action, saddle, strings, neck relief ...).
A guitar is far from perfect what fret board layout is concerned, therefore some tempering of the intonation may be necessary to get things harmonically balanced across the board.
I’m anal about intonation!
Click to expand...

It takes up too much space on the bench. I’ll stick with the Peterson for setting intonation.
 
Joe Bfstplk said:
I have noticed the plain strings' octave harmonics reading a hair sharp on occasion where the open string is dead on, and the fretted octave just a tad sharper, despite sounding in-tune with the harmonic. I guess it's an "ears, not eyes" thing.... ;)
Click to expand...
Isn't that the classic sign of needing to be intonated? Saddles need to be brought back to make the string longer.
 
Frodebro said:
It takes up too much space on the bench. I’ll stick with the Peterson for setting intonation.
Click to expand...
I agree, it's too big, but it's nice to have the option. I've touched up intonation between sets when something just wasn't right using my TC-Polytune Clip, and wouldn't hesitate to use my FM3 or FM9 for the same job.
 
fractalz said:
Isn't that the classic sign of needing to be intonated? Saddles need to be brought back to make the string longer.
Click to expand...

The open string and 12th fret harmonic should be exactly the same, but yes, if the fretted note reads sharp compared to the open string and 12th harmonic then the saddle needs to be moved back (away from the neck).
 
I don’t really know the technical difference between the strobe algorithm and the needle algorithm, but IIRC Cliff has talked somewhere about why they produce different results sometimes.
 
You must log in or register to reply here.
Back
Top Bottom