My David Crosby Blind Squirrel Method of Frequency Tuning

70sSanO

Well-known member
Joined
Apr 21, 2010
Messages
2,063
Reaction score
508
Location
Mission Viejo, CA
A little backstory...

About 5 years or so ago, I picked up a Fred Shields solid wood 3 string soprano ukulele. Not to argue about the legitimacy of a ukulele with only 3 stings, I found it to be the ultimate instrument for those motivationally challenged moments.

I play instrumentals and with only 3 stings it obviously forces the use of the fretboard. The issue was the "D" (5th fret A/1st string) note that lacked enough sustain to match the other notes. If I fretted it just right I could coax out a bit more, but that was way too much effort for the purpose of this instrument.

Having heard the folklore of David Crosby shaving the braces on his D-18, I thought that if a guy under the influence of that many drugs could successful alter the sound, how tough could it be for me.

I took some 220 sandpaper and attached it to my index finger with double side tape and started scalloping the center of the brace between the soundhole and the bridge. In my mind it was improving ever so slightly, then again, in my mind I buy a Quick Pick and feel I'm going to win.

I now moved into the blind squirrel phase of this endeavor. I thought that if I did a bit of the Charmin' squeeze on the soundboard, I could get things to free up a bit faster. I thought the approach was really working right up until the pop. While the "D" now had much more sustain, the rest of the notes lacked that crispness, especially the "A" which had the undesirable double note thing going on. I put it back into the gig back with a physician heal thyself determination, but the passage of time yielded no better result.

I located what I thought was the issue, the tail end of the brace on the treble side seemed loose. It took a few months to decide if I should tackle this, or let someone who actually knows something do it.

Armed with some Elmer's Glue-All (indoor in case it had to be removed), I made a feeble attempt to lightly sand around the area. My one (LOL!!!) concern was how to support the brace so it would glue back close to, but not exactly, how the original was done. In my mind I was still trying to improve that "D" note. The closest thing I had to a luthier's clamp in my box of tools was a yellow foam practice golf ball. When wedged between the back and the brace, it seemed like the perfect Goldilocks amount of pressure to use.

Well 24 excruciatingly long hours I am proud to announce that I actually did find a nut. I have no idea if it will stay this way, but I got crispness back and unbelievably, the dang "D" note has a lot better sustain without any special fretting technique.

John
 
"Blind Squirrel" I've used that technique in both repairs and playing. For playing I've use it to find strum/pick patterns. find one that sounds good and commit it to muscle memory. Repair, well every project seems to require some adaptation, like some sort of lever with a brace as a fulcrum point. When applying pressure on a brace I always support the out side face to keep it perfectly flat so there are no developing gaps under either brace.
The golf ball was clever
 
I do like a tale with a happy ending. Nice one!

John Colter
 
I think I placed it here because I find there is little actual guidance that can be gleaned from my inept attempt at trying to alter the sound of a particular note. I also placed it here because I find it fascinating, if even from pure luck, that I was ultimately able to achieve a desired result. That "D" note is still not perfect, but it is better, maybe at the expense of some other note; even if it is slight.

There is typically a note, or frequency, that is hidden somewhere on the fretboard of a ukulele that is off a bit. I have little knowledge on how a luthier builds to minimize that effect. But it is more apparent, at least to me, when playing individual notes than when strumming along.

When that section of the brace was loose the "D" note was louder with a lot more sustain. This was my middle-of-the-night-can't-sleep ukulele and for a couple months it had not been played. Prior to attempting this fix, I would put my finger on the brace and listen to the result on the "A" string based on how much upward or downward pressure I exerted. While that foam golf ball did the trick, I did test it out before I started gluing, so in all honesty I may have been more of a very near-sighted squirrel. But I had no clue that when removed how it would turn out. And I have no clue "why" it worked.

John
 
Sorry John. Failed attempt at humor. It certainly is a topic pertinent to building a ukulele. I suspect that you had a wolf note at D and by loosening the box you lowered the body resonance which eliminated it. I do not profess to be an expert in ukulele acoustics so I'm just guessing here. This is an introduction to the topic. http://www.southcoastukes.com/ti-tunings.htm
 
I appreciated your story. It reminds me of some of my stumbling in the quest for great tone. My aNueNue moonbird had the same issue on the 5th fret of the A string (and 3rd fret E string). I returned it to HMS and asked Andrew if he would be willing to send me another. The issue was identical in the second instrument. I found that informative and at least took comfort that it was idiosyncratic of this particular build- so I kept it. Further I emailed Tobias Elof (who I admire much as a player of aNueNue) and asked how he had dealt with it. His reply:

Ahh... I see.
I feel like each instrument develops through time with it’s own overtones the more it opens up.

I think the player shapes the instrument somewhat over time too. I’ve never thought about whether the 3rd fret on the c-string and 5th fret on the a-string felt more “dead” on the moonbird models, but obviously the octaves sing out more on any uke so I love trying to use those in my arrangements.

I also think that higher action on the strings makes the instrument sing more. I have mine on 3,2 mm.


My action is just 2.25 so I still would like to try his suggestion of 3.2.

I also found if I apply pressure to the soundboard just to the left of the bridge it improves the dead notes- but also decreases the overall warmth of the uke. Maybe there is a solution there but I don't know what it would be- thoughts?

My apologies for not moving this to a tech support thread..
 
Last edited:
Top Bottom