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View Full Version : Tenor Uke - Kasha style top bracing (first build!)



MiiNii
01-27-2011, 08:28 PM
Hi all
I'll give you a bit of background.. I'm Sam, 17 years of age and I've started to build my first musical instrument. My dad is a hobbyist maker who's built 7+ ukuleles (+3 cigar box ukes), 3 dalsamas and a guitar over the past 5 years.

Soh. I've decided to build a tenor ukulele with a kasha style top bracing (http://img812.imageshack.us/f/img0500gf.jpg/) for my first build..Don't ask why.
At least I've learned how to brace? haha..21 bracings i think you'll find on the top alone.

Here's a few photos..
back, tasmanian blackwood (http://.imageshack.us/i/tasmanianblackwood.jpg/)
shaped the neck, tapered the back (http://img138.imageshack.us/i/shapedtheneck.jpg/)
drilled the soundhole(s) (http://img211.imageshack.us/i/drilledthesoundholes.jpg/)
cut the soundport (http://img340.imageshack.us/i/cutthesoundport.jpg/)
Toooolllsss (http://img337.imageshack.us/i/shed.jpg/)

The majority of the timbers used in building this uke have been from a supplier in Perth, who has just released a brand new website (http://australiantonewoods.com/).
The softwood top is from a maker of very fine ukes by the name of Allen MacFarlane! (http://www.brguitars.com/)

Back & Sides - Tasmanian Blackwood
Top - BearClaw Sitka (spruce)
Neck - Maple
Headstock Veneer - Sassafras
Bridge - Tasmanian Blackwood
Fingerboard - Rosewood
Top Bracing - Jarrah & Cheesewood
Heelplate - Jarrah

Lexxy
01-27-2011, 09:05 PM
You sir, are talented.

Allen
01-27-2011, 09:55 PM
Hey Sam, welcome to UU. Good to see you joined up.

Isn't that a top from my stash?

It's coming along just fabulously. I hope you and John can make it back to Cairns this year and bring that little beauty with you.

MiiNii
01-27-2011, 10:17 PM
Thanks Lexx.

Allen! good to hear from you.
I'm sure cairns is on dad's mind!

Isn't that a top from my stash?
I believe it is from your stash - the Bear Claw Spruce/sitka. Great to work with! :D

ksquine
01-28-2011, 07:39 AM
Looking good so far. I hope you'll post pics when its finished.
So why did you go for the kahsa style?

MiiNii
02-06-2011, 01:46 AM
Although I said don't ask!... I guess it seemed like a challenge, was interested to see if it'd make a noticeable difference in tone.. Have talked to those who have used this bracing design with guitars and they've noticed it but are skeptical as to whether or not it will affect a tenor ukulele, due to it's size. (the plan was originally for a baritone - scaled it down). We won't know until it's strung up! Also, there's no way to judge by how much the bracing style has changed the sound due to not having a ukulele made using the same materials + fan braced to compare..If that makes any sense at all.

Glued the top yesterday..
http://img809.imageshack.us/img809/9815/img0240v.th.jpg (http://img809.imageshack.us/i/img0240v.jpg/)

..and trimmed it earlier today.

http://img145.imageshack.us/img145/7286/img0243cs.th.jpg (http://img145.imageshack.us/i/img0243cs.jpg/)

HornedOne
02-06-2011, 03:05 AM
looking good so far

Doc_J
02-06-2011, 04:09 AM
Wow. Beautiful.
Interesting bracing design. Are there plans for your Kasha design available?

ksquine
02-07-2011, 07:31 AM
Wow. Beautiful.
Interesting bracing design. Are there plans for your Kasha design available?

Hana Lima has plans for Kasha ukes in concert, tenor and baritone. I've used their fan braced plans before and they're quite good
http://www.hanalimastore.com/servlet/the-Plans/Categories

Nixon
02-07-2011, 07:55 AM
I doubt even after years of training, I doubt I could ever make a uke that nice. I've always loved the soundholes on the side, I'd assume it'd make it sound nice playing alone as the sound would be aimed at your face.

MiiNii
02-08-2011, 03:17 AM
Thankyou thankyou, very much appreciated - especially being my first build. Have updated my OP to include a couple of very interesting links! :D
The original KASHA plans I got were from Luthiers Mercantile International although they were hand drawn and I found the majority of the measurements were questionable. I then followed on using a tenor plan from Allen whom I believe got them from Hana Lima and have served me well - as ksquine has stated above. Thanks Nix, I'm sure you could! Yeah it'll be nice for playing alone although I hope the soundport won't be too large in comparison to the soundhole(s) for playing for people/in a group.

cahaya
11-25-2011, 05:51 PM
Hi ya Miinii,

Greetings from Perth. How's your project getting along? Please keep us in the loop and don't forget to post some of the photos :)

arpie
11-25-2011, 06:46 PM
Wow!! Well done!! Have you finished it yet? I couldn't load all the pics in the previous page - can you try & put some in the thread!! Looking forward to a sound sample too!

Got any pics of your Dad's ukes too?

Roberta

DeVineGuitars
11-25-2011, 06:49 PM
Love it! keep the pics coming!

Rick Turner
11-25-2011, 06:58 PM
I guess my only question is "Why Kasha?"

My own observation is that it's a wonderful intellectual exercise with little practical gain. Kasha's early pronouncements of huge gains in mechanical to acoustical energy transformation ( aka impedance matching ) just never materialized. Players have been far less interested in Kasha-braced instruments than many builders who have spent more time thinking about instruments than building and playing them.

Sorry for the relatively harsh assessment, but this has been going on for about 40 years, and has been eclipsed in the nylon string guitar world by lattice bracing and double topped construction, and it's never gained serious attention from players in the steel string world.

shrink9
11-25-2011, 07:10 PM
Great work--can't wait to see pics of it finished and (hopefully) hear it!!

Keep up the good work!

DeVineGuitars
11-26-2011, 06:42 AM
I guess my only question is "Why Kasha?"

My own observation is that it's a wonderful intellectual exercise with little practical gain. Kasha's early pronouncements of huge gains in mechanical to acoustical energy transformation ( aka impedance matching ) just never materialized. Players have been far less interested in Kasha-braced instruments than many builders who have spent more time thinking about instruments than building and playing them.

Sorry for the relatively harsh assessment, but this has been going on for about 40 years, and has been eclipsed in the nylon string guitar world by lattice bracing and double topped construction, and it's never gained serious attention from players in the steel string world.

What works for one builder may not work for another. I personally have found great success with the Kasha bracing system. Granted, I have made some changes to it to fit my needs, but I think most owners of my instruments would agree that it works.

... And, it's a fun top to build.

Rick Turner
11-26-2011, 07:08 AM
My real point is that the players decide what works and what doesn't, not the builders, and at least in the guitar world, where the Kasha system has been flogged for about forty years now, the results and the acceptance have not justified the promotion. Not that I haven't played some great Kasha inspired guitars...I have, particularly some of Steve Klein's, but I cannot name a single major player using Kasha guitars, either nylon strung or steel. It's not that they sound bad; it's that all the trumpeting of greatly increased acoustical efficiency just turned out to be hot air.

In fact, I think that a good builder can use a pretty wide variety of bracing patterns and achieve good results with proper attention to the flexibility vs. stiffness of various parts of the top.

And, as I said in my previous post, the new top designs that do seem to be getting the attention of players are double tops and Smallman-style lattice bracing. With nylon strings especially, what seems to really make the difference is proper control of the lightest weight tops you can do. The danger is that the instruments start sounding too much like banjos...loud, short sustain, and lacking in low end warmth.

BlackBearUkes
11-26-2011, 02:48 PM
For those who might be interested in a short history of how the Kasha design came
into being, here is a short history. Much more can be learned by going to the Guild
of America Luthiers, or reading "Gibson's, Fabulous Flat-Top Guitars" - a book by
Whitford, Vinopal and Erlewine.

In the late 1960's and early 1970's the guitar world changed, the imports were
becoming more abundant and the major US guitars makers had to make some changes.
Guitar companies like the new Ovation company were now on the scene, plus the
addition of many smaller companies and luthiers were cutting into the guitar market
of the big boys like Gibson, Guild and Martin. Gibson's answer to this was to
introduce a new MARK series of guitars. These guitars were the brain child of
designer Richard Schneider, Dr. Adrian Houtsma a professor of acoustic physics at
M.I.T.. Dr. Eugene Watson and Dr, Michael Kasha a well know chemical physicist at
Florida State
University. With lots of research Kasha and Schneider put together a new bracing
system, under Gibson's employ, that was suppose to be THE great sounding guitar of
the future. This new system used many small braces or tone bars that were a radical
departure from the X-braced guitars of the day. This new system was suppose to offer
top plate stability while yielding more vibration transmission to the four octave
range than the x-bracing system. So after time, more people joined the team and the
guitars were built and would be soon put onto the open market.

So far so good, there were four models of the new MARK series being built. There
were problems along the way with production, things got rushed but the guitars were
finally introduced to the market in late 1975. The problem was that the sound the
MARK series produced was not the sound the guitar buying public wanted. Even though
there were four models ranging in price from $439 to $2000, and many different woods
were used, they didn't appeal to the guitar market and were discontinued in 1979.

Richard Schneider then ventured out on his own with his designs, but concentration
mostly on the classical guitar. He also had a luthier's school in Washington state
were he lectured and taught other aspiring luthiers his theories, ideas and designs.
He worked on his designs until his death but never realized his dreams.
Unfortunately, the guitar never won great approval from his peers although some
luthiers still are trying to pick up the pieces and continue the work.

One of the problems that I and others have found with this design is that it never
fulfilled the promises, its just mostly hype. You just can't tell someone they are
hearing something that isn't there. To my ear the guitars always sounded a bit muddy
with too much bass. Once, a fine classical guitar player told me he didn't like the
Kasha design because "the damn thing got in the way of the music, it just wouldn't
shut up".

I have worked on a couple of the Gibson MARK series guitars in the past and my
impression is that they were over-built and the sound was flat without much
character. They were about 30 years old at the time so you think they would have
developed a bit.

Like Rick says, no major players are using these guitars. The design has flaws and
the science behind them doesn't work. If it did, you can bet the market would be
full Kasha guitars. I can't really see how it can benefit the uke world either, but
to each their own. Since this is MiiNii first build, for his sake I hope it sounds
OK and that he keeps building and learning.

Pete Howlett
11-26-2011, 03:16 PM
Kashas system only works if the front material is 'uniform' because it relies on behaviours associated with 'consistency'. As we all know, wood is organic and therefore variable, almost infinitely and from piece to piece in a resawn board can be very different in tap tone and elasticty. I researched Kasha for my degree and was unimpressed. It is a far too 'simple' answer to a complex problem that fails to take into account craft, knowledge and skill. I've recently watched a number of interesting guitar videos. One showed how voicing the front plate a whole tone above the back increased volume and sustain. In another video, guitars made by arkneweraguitars.com - copies of the fabulous Larson Bros creations with their laminated braces and tension rods sound just the same as the voiced one...

This of course is not to belittle your efforts or the fabulous build you are doing. It is merely to pose the question - why Kasha? It is 'guitar' technology. I have found that three 1/4" x 3/8" tapered fan braces on a spruce top ukulele provides all you need for a sweet, balanced yet punchy sound. If you achieve that with Kasha system - great. I know what I'd prefer to do, given I have to charge for every second spent at my bench....

Rick Turner
11-26-2011, 07:55 PM
I played one of the Gibson Mark prototypes that Richard and Abe made...met them at the factory in Kalamazoo in 1976...and it was a decent guitar. The production models absolutely sucked. Kasha himself told of having Guild make a Kasha classical...it was probably Carlo Greco who made it. Kasha took it to Segovia who promptly said something to the effect that it sucked. And that was supposed to be the peak of scientific guitar design at that point. Then Kasha spent all night with his hand inside the guitar shaving braces with a finger plane. Took out grams and grams of wood. Segovia still didn't like it. So much for those theories. Schneider kept changing things and trying different ideas. The two part bridge with the tiny connection between the 3rd and 4th strings that was suppose to be impedance matching turned out to vibrate out of phase with itself. Hmmm.... And, if you look at interferometric holograms of guitar tops moving, guess what? You don't see bass and treble sides to the top. You cannot say that the bass comes from the bass side and vice versa. It just doesn't work that way. Scientific observation trumps a scientist's theory in guitar...and uke acoustics.

What does happen, though, is that the top vibrates in a number of modes with sections of the top vibrating in and out of phase with other areas, and this tends to happen in the midrange. The air chamber supports the low end, the highs beam, and that fairly major in and out of phase stuff in the midrange literally EQ's the sound of the strings with a low end bump and a midrange dip. This is one of the reasons why folks like to apply a "smiley curve" electronic EQ to the signal from an undersaddle pickup. The pickup is actually more accurately reproducing what the strings are doing than the top and the rest of the box, so we try to emulate what the box does in a crude way with the EQ. In fact, it takes a kind of 3 D EQ to really do the job because you have to have a lot of control over the phase response.

Think of an acoustic instrument as being a very complex frequency and time filter, and that's in addition to the fact that the strings move the top and transfer that mechanical string energy to the instrument in three dimensions, X, Y, and Z...the torquing motion applied to the bridge of a "normal" flat top. BTW, that torqe of the Z forces of the strings occur at 2 times the fundamental and all harmonics of the strings. Interesting stuff... I once designed a Z axis pickup with the idea of being able to use it to drive guitar synths with double the tracking speed.

Liam Ryan
11-26-2011, 09:09 PM
The OP is a young bloke who wanted to build something a bit different to his dad. I think you guys are reading a bit much into it.

That said, the Kasha vs Normal discussion is quite interesting. Carry on.

DeVineGuitars
11-27-2011, 01:46 AM
The OP is a young bloke who wanted to build something a bit different to his dad. I think you guys are reading a bit much into it.

That said, the Kasha vs Normal discussion is quite interesting. Carry on.
+1
Keep up the good work and keep the pics coming!

Rick Turner
11-27-2011, 03:51 AM
Liam, I'm not reading too much into anything. On Internet forums, we're allowed for the conversations to be free ranging. It's perfectly normal for a thread or comment to lead off into different directions. The subject opened up here is Kasha bracing...and that inevitably brings up the whole issue of "how guitars (or ukes) work." Nothing with regard to guitar/uke acoustics is off the table once that Pandora's Box has been opened because Kasha's whole premise was that the tradition has it all wrong in the first place...whether it be ladder bracing, fan bracing, or "X" bracing. Kasha was adamant about "it" being totally unscientific...and therefore wrong.

I met him for an afternoon of discussion at Steve Klein's shop; I listened to his lecture at Healdsburg one year. He continued to declare the entire tradition of plucked instrument lutherie to be wrong.

I beg to differ... The shininess of the new, improved, and scientific has not proved to extend much below the surface in the real world of musical tools in this case.

Not saying that decent Kasha looking instruments can't be made, just saying they don't live up to the promises of vast superiority. The players have decided that, not me. I'd love for there to be a magic formula that makes guitars and ukes twice as good. Haven't seen or heard it in 47 years of looking and listening as a player and luthier. There are interesting variations on a theme. There are louder instruments. There are methods of building that achieve fairly predictable results. And players keep coming back to fan braced nylon stringed guitars and "X" braced steel strings.

Pete Howlett
11-27-2011, 10:06 AM
AND TO EMPHASISE - THIS DISCUSSIONWHICH HAS WANDERED INTO STRANGE PATHS IS NOT A CRITCISM OF YOUR BUILD OR DESIGN CHOICES :) :) :) If only my first build had been as sure footed...

Rick Turner
11-27-2011, 12:02 PM
I totally agree with Pete on this. No criticism of craft...just comments on the "science"...and it's not a strange path at all once you have started down the Kasha way.

Moore Bettah Ukuleles
11-27-2011, 12:56 PM
I must be doing something wrong. No matter what style of bracing I use all of my ukes sound pretty much the same. Leads me to believe what's more important is the builders approach to his/her work.
On a few occasions I've given a workshop on building ukes. Usually, all the wood was cut from the same source, we all used the same plan and nobody (but myself) had any instrument building experience. Yet there was a wide spectrum of tonal quality amongst the finished instruments. Some builders are heavy handed, others have more finesse, some go strictly by the book while others develop an intuitive sense.
I think any sound, tried and true bracing can be successful in the hands of a good builder. Personally, when it comes to ukes, I think the simple approach to bracing is the best one. It's key to understand WHY you are bracing, WHERE you are bracing and exactly what you are trying to achieve.