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PT66
Feb-17-2015, 11:59am
I am building a tenor guitar. Walnut back and sides with butternut top. 23 1/4 scale with 13 fret neck to body joint.130822 I am trying to decide how to compensate the saddle for CGDA tuning. Here is a sketch. Any thoughts?130823

BlowingRockNC
Feb-19-2015, 7:36pm
I'm not a builder, but it sure looks like you're building a really nice one. Good luck with the bridge issue.

GKWilson
Feb-20-2015, 2:30am
I'M not a luthier. But, you did ask for 'any' thoughts.
So, my thoughts are more in the form of questioning.
The Tenors I've seen with that type bridge have a single saddle with a slight angle back on the Bass side.
My question is, with a double saddle as shown, wouldn't the D string be slightly sharp and the A slightly sharp?
Gary
The picture is a little fuzzy. But that looks like one nice TG.

PT66
Feb-20-2015, 9:46am
I have decided to go with a single slanted saddle. My thoughts on the 2 piece saddle was to compensate the wound and unwound strings separately somewhat like a mandolin bridge.

Dolamon
Feb-20-2015, 11:59am
Bridge compensation is a bit more than mathematics based on scale length. It also varies on the string thickness. On most four string instruments the zero point is normally based on the thinnest string and all the others are 'offset' to reach compensation. This is an accommodation based on the open strings ... what happens when you start playing up the neck can wreak havoc on the tuning. So - it seems most luthiers and players will lend a deaf ear to the sharp notes. Interestingly, Peter Sawchyn ( http://www.sawchyn.com/ ), up in Regina has approached this issue a little differently (at least on my Sawchyn's). He set the zero string (at least he did this on mine) as the second string (D) and then set the A string below - or back from the D on my mandola. The C and G strings are set back from the D in what seems to be a more normal position. It makes a big difference in playing up the neck.

It took Peter a long time to work this out -and it works really well if you have a wound second as on my Mandola's. I'd think about putting a slightly thicker saddle on your guitar and then having a few spares if it gets off too far. To graph this out, the offsets are nominally C-2, G-1, D+/-0, A-1. (That's C minus 2 etc.)

I think your guitar is going to be a gem and the idea of using Butternut as a tone wood is a great idea.

BlowingRockNC
Feb-20-2015, 1:58pm
I have a picky ear, and intonation is something I really try to get a close to right as I can get it. I have two banjos. One is close to perfect all the way up the neck. The other sort of floats around, depending a just about anything and everything. Mostly, it's good, but not nearly as good as the other. My Archtop tenor guitar, which has a movable bridge, is set up just about perfect. It took a long time and some string changes, but I really like it. I just got a resonator tenor guitar, and I'm here to say that it's close to perfect. I still can't believe how well set-up it is, and you can't really move a bridge around much on a resonator guitar. I'm just luck, I know it, because I know folks who really make great banjos and guitars who are always seeking perfection. But, as they will tell you when not many are listening, there's really no such thing as perfect intonation when it comes to banjos, and almost never with a guitar either.

Granger
Feb-22-2015, 9:01am
This web site http://www.liutaiomottola.com/ has a saddle compensation calculator. I am building a tenor based on the 20.125" baritone uke scale and body size. It will be tuned DGBE. based on the calculation the following compensation is recommended:
E .189
B .377
G .228
D .333

Based on these dimensions your double saddle has merit and will produce better intonation. The reason for this is because of the difference in diameters of the CORE material in the bass strings, not their overall diameter. The treble strings will be .012 and .016, the core material for the D will be .015 and .013 for the G. Go with the double saddle design, doesn't take much longer really. I hope this helps. I could use some help on my X brace design for my build. thickness of braces and raw brace heights that you used would be valuable info for me.

PT66
Feb-23-2015, 2:29am
When I brace a top I start with the basic X brace pattern. In the case of a smaller instrument I would only use one diagenal below the bridge plate. In the case of a baritone size I would start with 1/4" wide by 3/8 tall braces. Then start shaving them away until the top tap tone sounded clear and ringy. The lighter the better as long as it will support the string tension and on a 4 string instrument you can go pretty light.
I did decide to go with a single saddle. I may add some compensation to the saddle itself. Will post finished pictures in a couple of days.

fox
Feb-23-2015, 2:55am
Hi Dave, have you ever though about fan bracing for a tenor guitar?
I just wonder as fan bracing is so popular with classical guitars and the string pull from a 6 string nylon is very much the same a 4 string tenor!

Granger
Feb-23-2015, 7:55am
Dave,

Thanks for the tip on raw X brace size!!!

PT66
Feb-23-2015, 3:18pm
I have used fan bracing on an instrument with the same body size. I used classical guitar strings and tuned it GCEA an octave below a ukulele. Ovation uses a form of fan bracing on its steel string guitars. There is a company called South Coast Ukulele that has an instrument they call a classical tenor guitar that is nylon strung and tuned like a baritone uke but tenor guitar size. Martin used X braces on its gut strung guitars before they switched to steel strings.

PT66
Feb-28-2015, 1:45pm
131195131196131197131198 This is the finished tenor guitar. Walnut back and sides with butternut top. I added a sound port and I like the way it helps you hear the instrument. The shot through the sound port shows the laminated X brace like the Larsen Brothers guitars.