Complementary texts for answers in the F.A.Q.:
TRUE TEMPERAMENT™ does not imply Just Intonation. It is physically impossible to implement Just Intonation in more than one specific key (and its relative minor) on any instrument with only 12 intervals in the octave. (Except perhaps for computer-controlled instruments using electronically generated sounds.)
What we mean by TRUE TEMPERAMENT™ is that our fretting system will give you super-accurate intonation over the whole fingerboard in the temperament it is constructed for.
What’s wrong with straight frets?
Standard equal tempered fret spacing is calculated from one single piece of information about the instrument – the scale length (the theoretical speaking length of the open strings). A divisor constant is used to determine the locations of the frets. The scale length divided by the constant gives the position of the first fret. The remaining length after subtracting the first fret, divided by the same constant, gives the position of the second fret, and so on.
The divisor used by all but a vanishingly small percentage of modern guitar builders is 17.817152, a figure arrived at by way of the logarithmic function “the 12th root of 2” (1.0594631). This results in precise mathematical fret spacing with the 12th fret at the exact centre of the calculated scale length. If the calculation is repeated for 24 frets, the distance from the 24th fret to the theoretical bridge saddle position will be exactly one-fourth of the calculated scale length. (The residual error is ridiculously small, less than one ten thousandth of an inch on popular guitar scales.) All very impressive. But this mathematical model is a gross oversimplification. It ignores virtually every physical parameter which governs the behaviour of vibrating strings, except one – speaking length. Tension and mass are not even considered.
The model assumes an “ideal” or “perfect” string – one which only exists in theory, not in the real world. It assumes, firstly, that the strings have no stiffness. Secondly, it assumes that all strings behave identically, regardless of their thickness, whether they are plain or wound, and the material they are made of. Thirdly, it assumes zero string height – and completely ignores what happens when the strings are pressed down on the frets!
The frequency of a vibrating string is determined by three factors: the speaking length, its mass, and the tension applied. All three of these factors are affected to varying degrees when a string is pressed down on a fret. Along the neck, the length and mass decrease by 50% per octave. Changing the length affects the stiffness. The tension is affected by fretting the string, as the string height is not zero. Pressing the string to the fret stretches the string slightly, increasing the tension and thus sharpening the notes produced.
The strings themselves vary considerably in diameter and construction (plain or wound), and thus react differently to being fretted. One single adjustment per string at the bridge (“intonation”) cannot possibly fully compensate for all these parameters at once, as they all vary in different degrees on different strings.
The only way to fully compensate for all these parameters is to adjust each and every string-to-fret contact point on the fingerboard separately, until each and every note plays the target frequency exactly. This, which is impossible on a guitar with traditional, one-piece, straight frets, is exactly what we do with Dynamic Intonation™, and Curved Frets™.
Previous attempts at implementing non-standard temperaments on the guitar, or of adding extra intervals, have relied on adding extra frets, or splitting the frets into separate pieces. This makes it very difficult, if not impossible, to employ modern rock and blues playing techniques like stringbending.
Our Curved Frets™ let you play the way you are used to.
Do I need to use a particular string gauge?
Our concert pitch electric guitar necks in 24-3/4″ and 25-1/2″ scale length are optimised for standard plain 3rd roundwound string sets from 0.009″ – 0.046″ & 0.010″ – 0.046″, to 0,011″ – 0,050″. We have found that normal intonation at the octave is enough to handle this range of gauges.
Our LOW TUNE model is optimised for 0.014” – 0.018” – 0.024” plain – 0.036” – 0.052” – 0.060” roundwound strings.
Using a wound 3rd is not an option if you have a True Temperament neck designed for a plain 3rd string.
Our steel-string acoustic fingerboard (650mm scale) is optimised for standard 0.012” – 0.054” bronzewound strings with a wound 3rd.
We also have a version for 641mm scale steel-string guitar with a plain (0.018″) G (as used by Steve Vai on his Ibanez Euphoria EP9 signature model).
Our nylon-string acoustic fingerboard (650 mm scale) is optimised for Savarez Corum Alliance strings (blue packet).
Our bass necks (34” scale) are optimised for standard roundwound 0.045” – 0.105” strings.
Can I tune down a half-step?
You can tune down and/or change string gauges within sensible limits. A half step down works fine. The limitation on how low you can go before the intonation craps out is most often the (plain) 3rd string – anything thicker than a 0.018″ usually sounds horribly “plonky” at, or close to, concert pitch, but thinner ones can become too floppy (and difficult to intonate) when tuned down – and again, using a wound 3rd is not an option if you have a True Temperament neck designed for a plain 3rd string.
We offer a LOW TUNE, standard (25-1/2”) scale version for “fourth down” tuning (B – E – A – D – F# – B), and verions for 27″ scale.
How do I adjust my guitar’s intonation after installing one of these necks?
In exactly the same way you would intonate with a standard neck – by matching the open string notes to the octave (12th fret) notes.
What do I do when the frets need dressing?
Fret levelling is done the exact same way as with standard frets. Re-crowning is more time-consuming than with standard frets, but any skilled luthier should be able to handle the job. (He will of course charge you considerably more than for standard frets!). We will be posting video on our website demonstrating the techniques and tools we use in our workshop, and will be happy to offer any help and advice we can. If you can’t find a luthier who will take on the job you can send the neck to us for fret dressing at a reasonable rate.
How do I get one of these necks refretted?
Refretting a TRUE TEMPERAMENT™ neck requires considerably more patience than refretting a standard neck, but uses essentially the same techniques. We can supply a new set of frets, or individual frets for repair situations.) We will be posting video on our website demonstrating the techniques and tools we use in our workshop, and will be happy to offer any help and advice we can. If you can’t find a luthier who will take on the job you can send the neck to us for refretting at a reasonable rate.
What happens when True Temperament guitars are used with other guitars, bass, piano etc?
Our THIDELL FORMULA 1™ temperament works just fine together with “ordinary” instruments. The offsets from Equal Temper are not so severe that they normally create dissonance.
What about acoustic and bass guitars?
We presently offer fingerboards in the THIDELL FORMULA 1™ temperament for both steel-string (wound G) and nylon-string guitars with 650mm scale length. We also have a version for 641mm scale steel-string guitar with a plain (0.018″) G (as used by Steve Vai on his Ibanez Euphoria EP9 signature model). We also have versions for 4- and 5-string 34″ scale electric bass.
How does your system compare to the Buzz Feiten Tuning System®?
We feel that, on guitars with traditional straight frets, the Buzz Feiten system offers a genuine and worthwhile improvement in chord consonance over standard intonation. However the improvement is limited, because you can only do so much with one tiny adjustment to the position of the nut and a little stretch tuning – you are trying to calibrate 132 fretted notes (on a 22-fret guitar) with only 7 adjustments (nut position + 6 offsets to the intonation points at the bridge). In common with other systems using nut compensation (either overall compensation, or individual compensation for each string) and “offsets” in the octave intonation, it is a compromise solution, albeit a better compromise than traditional intonation.
TRUE TEMPERAMENT™ calibrates each of those 132 fretted notes *individually*. No compromises.
Can your True Temperament frets be retrofitted to an existing guitar neck with standard frets?
Yes. But it is a very labour-intensive, and therefore expensive, procedure. There are two ways to do this:
a) Fill in the fret slots and rout new ones
b) Replace the fingerboard entirely.
Option a) is a very fiddly job that always leaves visible traces of the old fret slots. It also plays havoc with the machining. Moreover, the old position markers will not align correctly between the TRUE TEMPERAMENT™ fret slots, and will also need to be moved. Not recommended!
Option b) is almost always less problematic and time-consuming than option a), so ends up costing less.
Please contact us for details and pricing.
Can I have stainless steel TRUE TEMPERAMENT™ frets?
No, sorry. The only practical way to make our frets in bulk is to cast them. Stainless steel does not lend itself to our supplier’s casting methods. Our frets are precision cast in silicon bronze, chosen for its durability, low friction, and resistance to corrosion. It has also been certitied nickel-free by the Karolinska Institutet in Stockholm and, so is ideal for guitarists with a nickel allergy. (Stainless steel is *not* nickel-free. 60% of the world’s total nickel production is used in the production of stainless steel.)