Warning: If your eyes glaze over at technical stuff, please don't read this.
We know that a Gibson guitar's scale length is shorter than the stated 24 3/4". If you buy a Gibson-style board from Stew-Mac, it's actually 24 9/16". We've noted here before that a short scale Gibson bass has a scale length of about 30 1/4", not the stated 30 1/2" and that the old 34 1/2" scale bass was actually a shade under 34 1/4." Now from another thread it's confirmed that the nominal 34" scale Gibson now uses is actually a little shorter. From the photos I've been sent, it's about 33 3/4". I had always read that it was because Gibson used the fully compensated scale length instead of uncompensated. Could be, but not every string will be that long, so it didn't make sense to me.
Turns out it's apparently all because Gibson doesn't use the same rules for laying out frets that most everyone else does. They use the old Rule of 18: the first fret is 17/18ths of the way from the theoretical bridge to the nut, the second fret is 17/18ths of the remaining distance, etc. It works because the frets are properly spaced in relation to each other, and the chromatic scale is a compromise anyway. Problem is, using the Rule of 18, the 12th fret is not exactly half of the scale length. It's slightly less than half. On a 30 1/2 scale bass, it's actually at 15.139" for an actual scale of 30.278". On a guitar it's 12.285 for an actual scale of 24.57". And of course we intonate based on the 12th fret.
Fender and others use an exact formula that's been known for decades, and that's why the 12th fret measurement will be exactly half the stated scale length. No idea why Gibson doesn't do the same.
Gives some insight as to why 60s TBird bridges are in the wrong place. Thanks, Dave!
I think mine's based on the Precision scale length that JAE preferred - I'll check later...
kenny, you must be tootie. who is muldoon.
Certainly got his waistline...
Do we have a volunteer for Muldoon...?
Who's tall enough...? ;D
Anyone for Schnauser too...? :popcorn:
Wouldn't that mean all the notes on the 12 fret would sound flat compared to the corresponding harmonic? How should one intonate a Gibson?
Our guitarist scored a 1971 Les Paul Custom guitar the other day. And he encountered serious intonation problems. When tuned perfectly, somehow some of the chords played in (especially) the third position just kept sounding off.
He took the guitar to a luthier to check the bridge and the machine heads. To no avail.
At a second attempt the luthier noticed the nut, the first, second and third fret were not located correctly.
He moved the nut 1.5 mm back away for the bridge, the first fret 1.25 mm, second fret 1 mm and third fret 0.75 mm
This may very well have been the same issue as you describe Dave?
and we can't blame this on Henry. wonder if its also part of the slot nut versus end of neck techniques that fender versus Gibson use.
Quote from: dadagoboi on June 11, 2013, 12:24:24 PM
Gives some insight as to why 60s TBird bridges are in the wrong place. Thanks, Dave!
Very well could be.
Quote from: 4stringer77 on June 11, 2013, 03:04:38 PM
Wouldn't that mean all the notes on the 12 fret would sound flat compared to the corresponding harmonic? How should one intonate a Gibson?
Not as long as the bridge is placed properly for twice the actual 12th string distance. Take my Melody Maker, for example (since it's five feet away from me right now). Its wraparound bar bridge is placed so the high E is right about 24 9/16" while the low E is about 24 3/4". It intonates fine. But if it were placed further away so high E was at the stated 24 3/4", it wouldn't intonate properly. There were a number of Juniors and Specials that left the factory in the 50s with wrongly located bridge posts.
Quote from: Basvarken on June 11, 2013, 03:28:11 PM
Our guitarist scored a 1971 Les Paul Custom guitar the other day. And he encountered serious intonation problems. When tuned perfectly, somehow some of the chords played in (especially) the third position just kept sounding off.
He took the guitar to a luthier to check the bridge and the machine heads. To no avail.
At a second attempt the luthier noticed the nut, the first, second and third fret were not located correctly.
He moved the nut 1.5 mm back away for the bridge, the first fret 1.25 mm, second fret 1 mm and third fret 0.75 mm
This may very well have been the same issue as you describe Dave?
That's probably part of it, but there's more: I've also read that back in the day, fretboards were sawn on a different saw than the gangsaw that cut the fret slots, so sometimes the distance to the first fret was too short or long. And there's something else to consider: If you were to buy that Stew-Mac 24 9/16" Gibson-scale board and compare it to one on an actual Gibson, the 12th fret would be in the same spot on both but the other frets would not be. Using the Rule of 18, nut to first fret is 1.375" (confirmed on my MM) but using the exact formula the luthier probably used (which Stew-Mac uses) the distance is 1.379".
My guess is that the nut to first fret distance was too short, and while the second and third may have been fine in relation to each other, the luthier adjusted them according to the exact formula until everything worked. Hope that makes sense.
Have to read it again, but interesting!
I have noticed when intonating banjos (which, regardless of brand, are usually built in the Gibson "tradition".), ...including my old Gibson, the the distance from nut to 12th fret is always shorter than the difference from 12th fret to bridge. And yes, good intonation on my Fender instruments has always been easier to achieve for whatever reason. My Precision has to intonate well, because I tune it BEAD, and need high frets to get normal playing notes.
Quote from: nofi on June 11, 2013, 01:53:41 PM
kenny, you must be tootie. who is muldoon.
Oooo! Oooo! ;D
;D
I had no idea a Gibson short scale is really 30.278 instead of 30.5. That's interesting to know.
I have experienced some issues with my '67 eb-3. The old 2 point bridge is usually ok to intonate, but strung with Thomastik Jazz flats (round core)
the low E can't reach perfect intonation at the 12th. fret. I think it's .93 or .95, quite thin. I usually start intonating the G string with octave at 12th, and when tunig it i use the E at 9th. fret (G string) as reference for the other strings. Nevertheless, I'd have to file down the contact point where the bridge meets the post to be able to intonate the low E according to 12th. fret, the allen screw is all loosened but It's not quite there.
Anybody with similar issues using thin strings? It's really interesting to read this thread, maybe I should try to compensate slightly for the off-scale length and end up with better intonation...
amptech, TI jazz flats also have a .106 E string that come in the 32" scale set.
http://www.juststrings.com/toi-jf324.html
Gretsch basses are 30,3 too, according too their brochures.
Quote from: 4stringer77 on June 22, 2013, 07:34:50 AM
amptech, TI jazz flats also have a .106 E string that come in the 32" scale set.
http://www.juststrings.com/toi-jf324.html
Oh; thanks - but I do like the feel and sound of the thin ones. For my shortscale gibson's, .100 is about as thick as i go.
I have a .100 set of chromes on my fuzztone (with mod-bar) and a three point bridge, intonates fine.
But I like the sound of the thin Thomastik's better, the scale was just not 'short enough' on the two point.
I'll probably put Thomastik's on my whole collection the day I can afford it. I dug out a 32" epiphone 1820 from the closet the other day,
strung with thomastiks - 1995 vintage. They still tuned and sounded fine, amazing strings.
Seems to me that as long as the bridge is installed at the correct point for the scale length - regardless of what that scale length is - and the frets are correctly positioned, then the error is due to strings, not to the instrument design.
I may be wrong.
However, if I'm correct that doesn't mean you don't have a problem, but the answer may be a different gauge string rather than modifying the instrument.
Quote from: Pilgrim on June 22, 2013, 09:44:17 AM
Seems to me that as long as the bridge is installed at the correct point for the scale length - regardless of what that scale length is - and the frets are correctly positioned, then the error is due to strings, not to the instrument design.
I may be wrong.
However, if I'm correct that doesn't mean you don't have a problem, but the answer may be a different gauge string rather than modifying the instrument.
You're right. The actual uncompensated scale length is still twice the nut-to-12th distance. If the bridge is in the right location, then it's a string problem.