Build Thread: Osthoff Jumbo 12 String

[justonwo]

John has been making some great progress on the 12 string JS. You can see the sides are bent and wedged. A little artwork was added to the corner block on the cutaway. Very cool.

[riorider]

A little artwork was added to the corner block on the cutaway. Very cool.

Very cool!

It's these little touches that make these works of playable art special.

Looking good. Nice wedge.

Phil

[Tstalcup]

whooo..nice...I'm in the build queue for a mahogany SJ as well (six not twelve though). Going to be a long year. Not sure how people who buy build slots three and four years out manage the wait...dealing with John is a pleasure though. Looking forward to seeing how this SJ progresses. Did you ever resolve the issue of a straight pull, twelve tuner headstock?

[justonwo]

Good question. I know John has some serious designing to do to achieve straight string pull for a 12 string. It's certainly not a requirement for me. I'd be perfectly happy with a traditional headstock design.

[Tstalcup]

If you look at the Emerald guitar's website (the carbon fiber guy), they have a baritone 12-string bass in the custom section that is straight pull..its one funky looking headstock but they did get all the tuners on in that configuration. I'm not sure what the straight pull configuration offers other than that the string isn't biased north or south as it exits the nut. Not sure what benefit that imparts or whether anyone could tell in blind listening tests. It does offer a certain cool factor though and a guitar can't ever be too cool looking.

[justonwo]

Originally Posted by Tstalcup

If you look at the Emerald guitar's website (the carbon fiber guy), they have a baritone 12-string bass in the custom section that is straight pull..its one funky looking headstock but they did get all the tuners on in that configuration. I'm not sure what the straight pull configuration offers other than that the string isn't biased north or south as it exits the nut. Not sure what benefit that imparts or whether anyone could tell in blind listening tests. It does offer a certain cool factor though and a guitar can't ever be too cool looking.

I think the idea is to allow smoother tuning changes since the nut is less likely to bind the string. I can tell you in practice, having played one of John's SSP guitars extensively, that it is an improvement over a conventional nut in that regard. If you think about how long it takes to change tuning on a 12 string, this could prove to be useful, though of course not critical.

[John Osthoff]

This is a "draft" of what I wrote up regarding the SSP. I intend to put on my website (someday.) Anyway this is my reasoning for the change.

Initiatively this idea of lining up the tuning post with the strings in arrangement such that the strings remain completely straight with only a downward angle over the nut and saddle has been something I have been thinking of for years. This layout just seems to make sense. I have never been one to do something just to be different and much of my designs are steeped in tradition. When moving away from a conventional approach, there must be a significant advantage to the change before I will commit to it. The SSP headstock does have a non-traditional look for an acoustic guitar but the advantage of this design especially relating to intonation has convinced me to buck tradition and redesign my headstock.

Laying out the tuners to that the outside diameters of the tuner posts line up (straight) in-line with the nut slots has advantages over the traditional angular layout seen on most steel string guitars. The friction of the string on the nut is reduced which helps in tuning as the line caused by the tangent string is theoretically the only contact made by the string “riding” on the top of the nut. Theoretically the nut would not need to be slotted per se as the spacing could almost be determined by the tuner posts much like the pins determine the spacing on the saddle end. The lack of (the angular) side pull of the string on the nut slot is eliminated thus reducing the friction to only the “bottom” (tangent line) of the string. Changes in tension caused when tuning or bending will less likely to be “pinched” that often occurs when using the conventional (angular) string alignment. Even in a properly prepared angular slot a “pinch” can occur as string gets held in the slot causing the string to suddenly move all at once (making the screeching ping sound) resulting in a big change in pitch. While this is an annoyance in attempting accurate tuning, it can also cause problems with string bending. The biggest advantage of the SSP is the reduction of intonation issues especially when the use of a fully compensated nut which is now standard on Osthoff guitars.

Straight string pull has been around quite a while even seen on the Martin Stauffer style guitars of 1830’s. These guitars had an the tuners lined up similar to a Stratocaster with “Vienna screws” gear type tuners with all 6 tuning knobs protruding to the left. Creating a headstock for a modern steel string guitar with a straight-string-pull and three tuners on each side has its challenges as modern tuners will not fit into a symmetrical design. It is my preference to use Gotoh 510 Tuners on my guitars. This leaves for some challenging positioning of the tuners on the headstock while being still being able to create an aesthetically pleasing design. After a year of working with these different designs I came up with one that suits the needs from an engineering and ascetic standpoint. While this design certainly has a more “modern” look I still wanted to give a nod to some of the headstock tradition that came before.