I want to take this time to talk a little about scales on guitars. The scale is the distance between the back of the nut and the saddle of the bridge. The saddle, for those of you who don’t know, is the piece of bone across which the strings travel on the bridge. Is the scale any more than that?
Well, yes. If you are told that your guitar has a scale of 650mm and you measure it you might find that there is a difference. It might actually be 652mm, more or less. The luthier, the guy that made the guitar, might have adjusted the bridge to correct the intonation. Thus the measurement is not exactly what is published.
The correct way to measure the scale is not from the nut to the saddle but rather from the front of the nut to the 12th fret. In the case of the 650mm scale that measurement would turn out to be 325mm. Then you double it and get 650mm. Is that all there is to it?
No. Why do some guitars have longer scales and others shorter? Here is where my opinion comes in. 652mm has been the standard for decades. Still is, in my opinion. I do not have real long fingers and 650mm is very comfortable for me. But I have three guitars by José Oribe each with a different scale. One is 650mm, one is 656mm and one is 664mm. In playing them I notice that the long scale, 664mm, has longer sustain, especially in the high notes, and a much deeper (fatter?) sound in the bass. Those are the scales he presently offers. Tim McCoy, on the other hand, only offers a 650mm scale. And his guitars have plenty of power.
The difference between the shortest scales and the longest isn’t much. I would say it is about a half an inch and that is spread over 19 frets. Not much, but I personally do feel a difference, especially on certain chords, especially in the lower positions. I would say that most luthiers today favor the 650mm scale. Some guitarists today have guitars with even shorter scales. The difference in sound is noticeable If you have large hands you might feel more comfortable with the long scale. If you are playing for large audiences that would be a consideration also. But many famous guitarists have played for millions with the 650mm scale. One of the things that many forget is that you can be very satisfied with a guitar when you are alone with it. Sometimes comparisons throw you off. The important thing is that you like what you play and you try to get the most out of it.