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So, I've got a customer with a spare fender jazzmaster body and neck, he wants me to put a conversion baritone neck on the guitar and plans to tune it to A instead of B. Provided the fit is good should I anticipate any issue with intonation? I was looking at warmoth's site, I've had good luck with other warmoth products, and the logic seems sound. I guess my question has more to do with the extra low tuning and the inevitable giant strings this client will use. I've worked on two of his other jazzmasters, one a '64 that he put 11-62 gauge strings on and tuned to standard, and another we tuned to open D minor and had 13-72 gauge strings.

Are you going to have to move the bridge due to the longer scale length?

Apparently with these warmoth necks they do the scale conversion with the nut/fret placement so you don't have to move the bridge. I guess they do the math and work it backwards from the bridge. Also the neck would be wider but they do an undercut thing so it will still fit a standard fender neck pocket.

https://www.warmoth.com/Guitar/Necks/Co ... Necks.aspx

My main concern was the lower tuning and thicker strings messing with intonation beyond the realms of adjustment. But I may be overthinking things. With the extra tension from the baritone scale length going from B down to A shouldn't be too much different the going from E to D on a regular guitar.

It will be fine.

_________________
"Act your age, not your shoe size" - Prince

I gave you a link to Liutoio Mottola's little wizard that will calculate the compensated length of any string at any tuning at any scale if you know the physical properties in your question about the saddle location on the LG-1. You must have not read it. It will answer your question.

The simple first order formula for string tension (Mottola's, D'Addario, a dozen other places) will let you calculate the tension for any gauge of string at any scale length at any frequency. That will let you determine if your choice of strings will play reasonably.

Or you could just ask here.

Remember that there is a very good chance that your baritone string set will have a wound third.... Also, it is my understanding that all Jazzmasters were 25.5 and it is only JagStangs that are 24 inch scale but it doesn't hurt to confirm before you dive in.

Hi Freeman, I haven't read it yet, I've tucked it away for later. I got sidetracked with some other things before diving into the LG. Yes Jazzmasters are a 25.5" scale, Jaguars as well as the Jag-Stangs you were working on are a 24" scale. The necks warmoth sell as I mentioned in an earlier response are designed to convert standard scale instruments to other scales. They work the math out backwards from the bridge and then construct the neck accordingly. This way you can adjust the scale without moving your bridge. So the neck I was looking at on warmoth's site will convert in this case a 25.5" scale guitar to a 28.625" scale guitar. My worry as mentioned earlier was that the customer in the end will be drop tuning and using thicker strings, so he'll be moving beyond the scope of what is typical, and I know thick wound strings can sometimes make intonating a guitar a bit of an adventure. If this job gets past the looky-loo stage I'll read that article to make sure there are no nasty surprises. He has started talking about refinishing the body he has to black with gold metal flake over top, as well as a bunch of other things, personally I think he's getting to the stage with his aspirations where it makes more sense to start from scratch than try and cobble a bunch of extras together.

I know exactly how the Warmoth neck works. I helped someone on another forum do a baritone conversion. What I'm trying to do here is help you understand how it works and how YOU can be confident it will work. Thick strings aren't any different from thin strings - the physic is the same, the math is the same, the results might be different.

Gotcha thanks Freeman. I misunderstood your initial post, I thought it was strange to have to explain that to you.

I'll be sure to check out the article you sent earlier.

May I humbly suggest that if you don't have it, pick up a copy of Mark French's book Technology of the Guitar. He actually has two books out,Engineering the Guitar goes into a lot more detail and uses some pretty high level math, with Technology you can get by with high school math. Mark does a pretty good job of covering the physics behind both acoustic and electric guitars - if you understand this (and apply it) you won't have to ask as many questions here.

And as far as baritones are concerned, remember that I have built a long scale 12 string which is usually tuned to C, it is easy to fret and plays in tune.

Thanks Freeman, I'll add that book to my reading list too. Any other book suggestions? I've got a few on hand, The Cumpiano book, a couple of Erlewine's, a book by an english guy named Jonathan Kinkead, and the Hiscock one as well as a few luthiery related things. I've read most of them, at least cursorily. I enjoy reading, but I'm not sure it's my best learning method, I tend to learn better by doing something, stumbling through the steps. Which is probably why I show up here with so many questions, (hopefully not the same ones over and over ) I find it easier to tackle the problem/step I'm in, in the moment, (I do use the books too though!)

I have and recommend all of the books that you list - but they are all about how to build this or that. French's book (and the Mottola links) are more about WHY - why does this guitar play out of tune, why are these strings hard to play... Belonging to the Guild is golden, but then you will start down the rabbit hole of buying every big red book and all the back issues. You are so close that you should plan to go to the next conference (2020 I think), I'll buy you a cup of coffee.

I also have a huge number of internet links and threads book marked (and somewhat sorted). If I wanted to find some bit of information I have a reasonable chance. All my build threads are marked, a lot of technical information, links to websites and blogs. For example, I have a folder on finishing and right up at the top is Brian's incredible table of everything that can go wrong - you would be surprised how often I refer to that.

I'll look forward to that Freeman!

That's a super cool calculator Freeman!

I had to change the strings on a personal guitar, and thought I'd give it a whirl and set the intonation on the guitar using the measurements it spit out. Worked like a charm, a little tweaking afterwards, but I can see how useful that might be when setting up guitars, it would get me in the general ballpark and hopefully save a little time tweaking afterwards.

I also used the baritone guitar in my initial post as a hypothetical situation and was able to answer my questions, at least hypothetically.

One thing I wonder though, have you found a reference for core diameters of strings? No big deal on my guitar because I had the strings in front of me, but for my hypothetical situation I had to best guess that info a little bit as I couldn't seem to find that info anywhere online.

Just another resource on this sort of thing, I can offer the compensation calculator that I built in Excel when I was designing a multi-scale baritone. If I recall, I was using one of the references also used by Motolla for the math in his online calculator. Yes, it is a bit difficult to derive string data — the most difficult is string mass — but if you have a precision scale (I happen to have one) and are prepared to sacrifice a set of strings, you can easily generate all the parameters required.
What did I learn? If you’re building a baritone and want to intonate well, you should be prepared to use a thick saddle to properly accommodate all of the string compensation lengths. Skinny saddles really don’t work well. All of the references are in the blog post found here:https://www.mullinguitars.com/2015/10/compensation-calculator-for-steel-string-guitars.html


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AGAIN - for a Warmoth baritone neck... it will be FINE. They did the math so you don't have to.

_________________
"Act your age, not your shoe size" - Prince

I used the StewMac online fret calculator to find scales between 28-29” that placed the 23rd fret almost exactly where the 21st fret is on a 25.5” neck. I did this so I could have the last fret (23 frets on this one which upsets a guitar friend of mine!) was the same distance from the end of the neck as the 21st to help me with the geometry of the template I made, and so the saddles would be in the same place with standard Strat geometry (i.e. bridge in the usual position for a Strat). I got to 28 3/4” and the intonation is perfect. I think Warmoth’s is 28 5/8” from memory.


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I hear you Chris, I'm totally comfortable with the warmoth neck.

I have enjoyed falling down this rabbit hole though!

Conor