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Author Topic: Anyone else having Sunbeam intonation issues lately?  (Read 684 times)
sgarnett
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« on: March 06, 2011, 06:07:39 AM »

DR Sunbeams have generally been my favorite strings for the last year, with the exception of one Martin that sounded horrible with them. Today though, I've gone through several sets of 12~54 with 4th strings (.032) that intonate very strangely. The 3rd might be a little a little weird too, but not nearly as bad as the 4th.

Basically, if the 4th is tuned up to D, it is VERY flat (maybe a third of a semitone) at the 12th fret. This is on a new guitar, so at first I thought something was wrong with the guitar. I put a capo on the first fret and retuned, but there was no change at the 12th fret. Other frets seem just as wrong. I measured the saddle position and angle compared to another Larrivee with the same scale, nearly identical setup, same strings (but older, and intonating fine). So, I used a piece of steel pressed against the string to see how far the saddle peak needed to be tweaked. Over 1/4"??? WTF??? That is well beyond tweaking the saddle. On a whim, I checked the harmonic position. It should be only about a mm past the fret crown (due to the saddle slant), but instead it is almost halfway between the 12th and 13th frets. Whoa, that's at least 1/4" away from the center of the open string. Something is very wrong. I tried a string from another Sunbeam set, and it's just as bad.

Then I replaced the string with one from a John Pearse set, and all is well. I also replaced the 3rd string with a Pearse. While the Sunbeam 3rd wasn't nearly as bad as the 4th, the Pearse 3rd also improved the intonation.

They are installed with a Z bend (two crimps) at the tuning peg, and the end isn't trimmed until the string is tuned up to pitch. Pulling the pin and twisting the string twice to tighten the wrap had no effect.

My only guess is that the string winding isn't uniform, so the density of the string drops at it gets farther from the ball end. Either the winding process isn't well controlled, or the wraps are slipping a little before they crimp the end. It has to be something like that for the harmonic node to be so far off-center on the open string.

Has anyone else run into this? I like Sunbeams, but maybe it's time to start paying up for Newtones ....
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jandrew
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« Reply #1 on: March 06, 2011, 06:38:48 AM »

I had a similar experience with the 4th string on my second set of DR Rares (I had liked the first set) -- not dead at all, but intonation was way out of whack up the fretboard. I sent two messages to DR and both went unanswered. That turned me off DR altogether (I can handle a bad set, but not poor support) -- except ... I still had 2 sets of sunbeams to try out as well and took a chance on them anyway. Turns out I *really* liked the sunbeams and I've kept using them for the past couple years without incident (knock on rosewood). You should try to contact DR, perhaps you'll have a more positive experience with them than I did.

cheers,
andrew
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Andrew J.
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« Reply #2 on: March 06, 2011, 05:57:50 PM »

The string may have had a kink in it and was straightened out.Because of the kink it will tune up but play out of tune.
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« Reply #3 on: March 06, 2011, 07:15:00 PM »


Then I replaced the string with one from a John Pearse set, and all is well. I also replaced the 3rd string with a Pearse. While the Sunbeam 3rd wasn't nearly as bad as the 4th, the Pearse 3rd also improved the intonation.

Seems like you may have diagnosed it correctly when laying blame on the winding.  Sounds like a manufacturing glitch.  I had the same problem with a set of DR Rares some years ago and I almost started to pull the saddle off and adjust it.  I decided to try another string and was back in business, same as you.  Another thing I ran into on a guitar with the saddle in close proximity to the bridge pin was the windings came up too far .  Sometimes it makes a difference and sometimes it does not. I put a couple of extra ball ends over the string and it intonated perfectly. 
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sgarnett
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« Reply #4 on: March 06, 2011, 07:35:38 PM »

That's possible, I suppose. Two D strings (so far) had the same problem, but they could have been made by the same operator.

I wondered if excessive stretching over the peghead or the bend at the bridge pin could be causing it, but I think the significantly off-center harmonic node probably rules that out.

The strings looked OK coming out of the package. Both sprang out straight when removed from the package.

Even if a kink in the core was perfectly straightened, it would work harden that section. I guess improper operation of the winding machine could do the same if the core was allowed to flex during winding.
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« Reply #5 on: March 07, 2011, 03:47:57 AM »

Run the string between 2 fingers,its the only way to tell if the string got kinked.Check the packaging's lot numbers and see if there from the same lot.I had this happen once and after that I always check.I also won $100 from a player in Miami because he said that couldn't be it.To this day he only growls when he see's me. :bgrin:Mine where from Dean Markley and they replaced them for free.His were GHS.
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sgarnett
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« Reply #6 on: March 07, 2011, 04:14:29 AM »

I should have kept the bad strings, but I didn't. I've got a few more new sets though.

I couldn't find a lot code on the DR packaging.
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