PDA

View Full Version : Intonation/Compensation



Bruce Sexauer
02-05-2009, 08:59 AM
Hi, this is my first post on this forum. I have been making guitars for years, but have discovered the Uke, and have completed my second one. Nylon strings are not my forte, and I am struggling with saddle placement on the one I have here.

It seems like I cannot get accurate intonation across the strings. Using a 3/32" bone saddle I am slightly flat on the G and A while OK on the C and E. I have compensated the saddle in the correct direction as far as possible, and even rerouted the slot (I made the bridge sort of like a classical guitar but with a set in saddle like a modern Martin guitar). The strings are Ko'olau Gold, high G, and it is a tenor. I am looking for advice.
http://sexauerluthier.com/13thfret/tenorbridge.jpg

Kekani
02-05-2009, 01:26 PM
String swap?

For my Tenors, I actually stretch compensation across a 1/8" saddle, for low g tuning. There are some builders that actually throw in an angle for compensation. I know, logic doesn't seem right when Classical Bridges are straight across.

Getting back to strings - there are a LOT of players that experience intonation problems when they change strings, and they blame the instrument. I've not heard of Ko`olau's causing problems, though. Usually its Aquila that causes problems (except on the lower end instruments, for some reason).

Welcome to our wonderful world.

-Aaron

Bruce Sexauer
02-05-2009, 02:44 PM
Thank you for the thoughts. I think I am going to have to replace the bridge if I am to put the saddle any closer to the nut. Not so hard, but I hate to have missed by that much! Professional Pride.

Kekani
02-07-2009, 09:22 PM
What's the scale length, and did you add any inches (or thousandths of an inch) for compensation?

One solution for your g string is to tune it low g, that may get you closer. Otherwise, higher tension strings might serve you well. If this is a Tenor, I would try D'Addario Pro Arte J46 Classical Guitar strings - the first 4 strings would be low g. I think the Pro Arte `ukulele version may be the J71, which is a high G set (found in the Underground store). These should add tension, and have you go sharper as you fret.

You stated nylon is not your forte' - I know what you mean, when I strung up my Tiple, I found steel to be quite different as well. Nylon on `ukulele, believe it or not, is really finicky, the higher quality the instrument.

I guess you figured out that I'm strongly suggesting a string change at this point. Much easier than resetting a bridge. The more I thought about it, the more I'm leaning towards higher tension strings on your instrument. Yes, I use Classical Guitar strings. Didn't make sense to me at first when I heard some guys doing that, because I thought "there has to be good `ukulele strings out there. Personal preference at this point, I guess.

In the end, you see that D'Addario repackaged their Pro Arte Classicals and called them Pro Arte `Ukulele Strings. I hope Savarez does the same (BTW - I use their Alliance series Normal and Hard tension). My favorite D'Addario is the new Titanium Trebles mixed with the Gold wound 4th string (80/20 bronze wound) - the transition between the trebles and the wound strings is really nice, IMO.

Be sure to post your findings.

-Aaron

ukantor
02-08-2009, 12:45 AM
Are you detecting the faulty intonation by ear, or by using an electronic tuner? It is possible to drive yourself mad trying to achieve absolute perfection, as dictated by an electronic tuner. If you can't detect the differences by ear, I'd say accept it.

Ukantor

Bruce Sexauer
02-08-2009, 01:23 PM
When I say nylon in not my forte, I mean I have made about 350 instruments, mostly guitars, and only 3 "classical" guitars.

I have had to edit this post because I found my problem, and it is a bit embarrassing. I believe I oversanded the nut end when trimming the binding to the end of the fingerboard, and shortened it by about 1/16"! So I cut the top of the nut back to where it should have been, and the Tenor is close enough to make music now. I am not used to working on such delicate parts, yeah, that's it. The fretted octave was about 15 cents flat of the harmonic on the g string, now it's 2 or 3 cents with the saddle break point all the way forward. Still will require a wider saddle, but not by much. I have about 5/100 compensation which works for the other 3 strings OK, but I guess the g may require 2/100". Steel strings take many times that.