Tiple intonation

[Terry Straker]

A customer just dropped off a nice T28 Martin tiple complaining about poor intonation. He says he heard that Frank had done an intonated saddle for one of these. I can't seem to find any information on the web site about this, so am asking what Frank or anyone else has done in this regard. As I am sure most of you know, the original saddle is a tiny mando fret, and the bridge is pretty delicate so I am leary of cutting any of it away to accommodate a saddle slot. Anyone have a great solution?

[John Fonner]

Thanks Mark, I really appreciate the advice.  I'll save my change for the next vintage mandocello that comes on the market. :)

[John Fonner]

Oh, and another thing, I have mine tuned GCEA like a uke but have seen some posts about lower tunings. What is TST (Tiple Standard Tuning?) Also, is the wound string more commonly in position #9 or #10? I've seen it both ways. Paul Hostettler's diagram shows the wound string in #9 if I'm reading it correctly.

[Paul Hostetter]

Yes, the fourth course, while reëntrant, is still an octave pair. And while some people in recent years have strung that low course with the wound half of the pair on the outside, all the early Martin catalog imagery shows it as I have it above: with the high octave string on the outside. It sure sounds better that way. One can, of course, play single-note melodies on these, but they were really designed and meant to play chordal accompaniment.

[John Fonner]

Thanks, I put the high octave string on the outside because the outside slot in the nut seemed smaller but I wondered after I saw several pictures the other way. I like the way it sounds striking the high string first so I'll leave it knowing I'm "to spec."

[Robbie Collins]

Nice bridge! I just spent some time moving fret wires around on a Hofner archtop bridge so I was interested to see your solution.

Question: Is there a reason for the uneven spacing between the string courses or is it just convention? Not criticizing...just curious.

[Paul Hostetter]

They are even: center to center of each course.

[Robbie Collins]

I guess I was looking at it backwards. I was thinking about the amount of space between each course.

[Terry Straker]

So... another tiple showed up, this time from Hawaii-- this one did not intonate like the T28, so I had to make compensated bone saddles because the fret wire wasn't going to cut it.

[Scott Mann]

Hi guys, I have been watching you cool tiple bridge mods.

So I am building a Columbian style tiple next spring and would love to use some of your knowledge on this bridge construction. I guess I am wondering as far as luthiery goes, do you use an equation to figure out the likely measurement of intonation for your saddle placements?

My music physics has been a while past and I could dig deep into remembering how mass, string length and frequency work together.

Maybe you have some ideas for me or maybe I should just take your pics as a guide to figuring everything out for myself?

Love the work,

Scott

[Terry Straker]

I'm pretty sure Frank gave a method of mathematically calculating string length earlier in this post or on the main info page Scott. I used it on the first Tiple bridge I made (shown at the start of this thread) to determine how far off Mr. Martin placed the saddle so I could make a bridge that would would allow me to fix the atrocious intonation on that T-28. Search a bit and you will find how to do the calculation. When I do these bridges I fabricate and install the bridge on the instrument but I don't cut the saddle slot or slots. I then string the instrument up with the strings that are going to be used and tune it to the proper pitch. I use the smooth shank a drill bit as a temporary moveable saddle under each string (one at a time) and use my strobe tuner to determine the exact spot that string needs to have it's saddle placed and make a mark on the top of the bridge. I then move to the next string and repeat. When all the strings have been done I unstring it and cut a slot or slots in the appropriate spot (guided by the marks I have made) so I can get each string to intonate properly. You can notch the saddle as in the above pictures if needed to get each string exactly right. As they say...it's not rocket science And I am sure there are other excellent ways to skin this particular cat. This one works for me. Good luck.

Terry

[Kerry Bannister]

Nice job on the intonation of a tiple! I build ukuleles,tiples and dabble with the intonation problems on vintage tiples also;have had a couple Regals,a Martin T-15 and a Harmony Patrician..besides a couple of my own and plan to make some more this year.I eventually made a separate adjustable neck/fretboard/bridge setup for figuring correct compensation by using the same strings on that and adjusting everything around once the nut and 12th fret(scale) are set ..but I have been trying to stay with fret wire.I guess I'll have to resort to using bone saddles also.

  I also need to "refine" my adjustable "movable fret" on my compensation calculator neck to check the 3rd,5th,7th while everything else seems correct,just to double check things.Right now that piece doesn't allow it to slide to the earlier fret position from the nut.I just need to shorten a couple pieces,maybe cut the center slot longer..minor changes to make it work for shorter scale/fret points..

  Even though the 12th seems correct,I run into wrong intonation at around the ,3rd,5th and other frets within that area once the instruments are strung up.I'm curious as to: 1)the size of the strings(set you used(wound and plain)..2)if you ran into similar problems in that area or was that T-28 "spot on at the earlier frets..3)Height of the strings over the 12fret...

  I've been doing more of my building using a baritone scale (like Kamaka,Lapinad) which seems to give more leeway in the GCEA tuning.Also I have little faith in the brass plate and string holes for the string retention on the bridge.I've fixed too many pulled off bridges on tiples..and went to pins and the strings held under the top soundboard instead.

  Anyhow keep up the good work!It would be nice to see if it is totally possible to intonate a tiple up and down the fretboard.Let me know!Thanks..

[Scott Mann]

Hi Kerry, though i am still building my first Tiple, your questions about better intonation in the earlier 3rd, 5th and 7th frets make me think that the adjustments must be done at the nut.

Your saddle can only cover the 12th fret exactly and everything before that that will minutely be off.

So aside from a fan fret absolutism, only a nut compensation can give better intonation up to the 12th.

As far as calculating, sure wound/plain choices and action at 12th will change the end results.