Here's the pic of subject guitar. You don't see a problem?
Guitars are never really in tune across all of the fretted positions for some with perfect pitch a guitar never sounds in tune. The fret spacing for each string would need to be modified for perfect intonation because the characteristics of the strings play a role. From what I heard guitar intonation is a way of spreading the inherent error in the guitars design as thinly or evenly as possible.... She's a violinist so she tunes by ear, as do I. (She's perfect pitched ...
That is very interesting...johnparchem wrote: ↑Thu Jul 27, 2017 3:36 pmGuitars are never really in tune across all of the fretted positions for some with perfect pitch a guitar never sounds in tune. The fret spacing for each string would need to be modified for perfect intonation because the characteristics of the strings play a role. From what I heard guitar intonation is a way of spreading the inherent error in the guitars design as thinly or evenly as possible.... She's a violinist so she tunes by ear, as do I. (She's perfect pitched ...
The problem with just some notes on the same string being out of tune may be an issue with the guitars resonant frequencies. I read in the Gore\Gilet Design book that a strong resonant peak near a note will tend to repel a played note away. This is some times seen tuning open notes as well where it is hard to tune to a note. I wonder if the same issue exists tuning down a semi tone.
Thanks. I was guessing down centreline, as no one until you said so. Confirms my thoughts, and compensation either side ought to be 1mm thereabouts (from above someone else said not more than 2mm end to end at saddle).John higgon wrote: ↑Thu Jul 27, 2017 5:09 pmThe scale length is from the edge of the nut (fretboard side) to the edge of the saddle (soundhole side). There shouldn't be much difference in that measurement from one string to another. I just make the measurement down the centreline of the fretboard. It's unusual for guitars to be significantly out of tune. I see that your guitar has a shorter-than-usual scale length, so it's worth checking that the bridge is in the right place, and it's a quick and easy check to make. However, I'd be surprised if the tuning problem is down to bridge position, frankly. It's possible that a full-size body has been married to a short neck, or vice versa, but that seems unlikely. Even so, worth a quick check.
simonm wrote: ↑Thu Jul 27, 2017 10:55 pm
Found it again. https://www.youtube.com/watch?v=C8BNYhLoSvo The master class is with Marcelo Kayath and at about 9.55 in this video he says something to the effect of … "forget it, a guitar can't be tuned. All you can do is get it equally out of tune" … Very funny in Brazilian. Kayath is actually avery interesting player in any case. Dropped out of playing to become a banker and recently came back to playing.
Given that the guitar owner has perfect pitch is may be a battle to find a suitable guitar. Some guitars have better intonation than others but they are in a different price category. On the other hand compared to a pro violin all expensive guitars are pretty ordinary prices or even downright cheap. Price alone will not necessarily be an indicator of better intonation.
I recall reading about someone with perfect pitch who gave up guitar because he/she could not stand the fact that the instrument was always out of tune.
I'm really glad that you and others all of similar opinions and what to check, as that gives comfort as to what next.Keith wrote: ↑Fri Jul 28, 2017 10:04 amscale length = nut to 12th fret x 2. see Ramirez book, posts here at Delcamp.
string length = nut to saddle
difference in lengths is compensation. most guitars have a 1-2mm compensation. many posts here at Delcamp on the subject.
sometimes it is best to start from the beginning. take off strings and toss. the strings could be stretched out, defective, etc. buy reliable set of strings--if the scale length is 630mm maybe high tension strings? make sure tuners are working correctly and lube if needed. restring using accepted tying methods. let strings settle. try it out.
rather than looking for some real bonehead mistake one should start from square one. there is a reason why most techs ask the question, is the machine plugged in, before asking additional questions. the guitar is factory made and most likely the fretboard was cut using CNC or a template so it may be safe to say all is well in that regards. that said it could have been made on a Friday at 3 p.m. when the workers were looking forward to the weekend and were not paying attention and someone used the 650mm jig for the 630mm fretboard.
Ah I se what you mean... And it might mean after the "mapping" I might be able to change the compensation by using compensated saddle such as : tusq-acoustic-saddles - I noticed on my own guitar, which doesn't have this intonation problem and this guitar doesn't seem to have - the compensation on this particular one seems mainly the diagonal saddle.astro64 wrote: ↑Fri Jul 28, 2017 4:07 pmMy advice would be to systematically map the inaccuracies across the fretboard. You may have some frets out of place. Put a good set of string on, let them settle for a few days. Bring open strings in tune. Check they hold tune. Now with a good tuner map for each fretted note on each string how far the tuning is off. Write them down on a chart. If you have one or more frets in a wrong position it will become obvious. If you see a systematic pattern of notes going sharp or flat as you move up the fretboard the saddle position is off. Note that the third string will generally be the most off because it needs more compensation than others. But the systematic patterns should still be there if either frets are in wrong place or the guitar is not properly compensated (i.e. saddle in wrong place or needs fine-adjustment to get the break point for each string correct).