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       July 21-26, 2013            Oct. 20-25, 2013

In 1985, I had the privilege of bringing Bertha Loar Westerberg to NAMM, and she was excited to see how the show had grown since her last NAMM attendance with her husband Lloyd in 1943. Bertha and I visited the Gibson booth so she could see Gibson's mandolin progress, and we had the chance to pose for this Gibson promotional photograph. On the left is Bruce Bolen, Gibson's VP of product development and Artist Relations at the time, Bertha, and me holding an F5L mandolin of the period. I remember that Bertha, Bruce, and I had lunch that day, and Bruce had the rare opportunity to hear Bertha's view of Lloyd's work at Gibson.

NAMM has grown tremendously since then. This past January's show was held at the Anaheim Convention Center where exhibitors from around the world filled all four main halls plus the basement of hall D (where most of the acoustic instruments were), and the attendance hit an all time high of 95,709 during the four-day weekend! Walking through the aisles was like being at Time Square in rush hour. Amazing!

Our goal was to visit with our vendors, look for new products that we feel would serve you well, and discuss our plans and needs with our suppliers for 2013 and beyond. We met with the folks from Gotoh, visited with our case manufacturer, focused on new products with the Peterson staff (the folks who produce our strobetuners and StroboSoft�), and looked around to see what's new. Of special interest to us was getting a better handle on the current state of the art in mandolin pickups and amplification systems.

The subject of amplification seems to be high on everyone's list and many of you have communicated with us about pickups regarding the right one to use, and the right place and method to mount them. In addition to amplification being one of our goals for this NAMM show, we're also engaged in a development project to study the various pickups on the market today, test them in various locations within the instrument, and work with a few select manufacturers to help develop the ideal pickups for the mandolin.

To this end, we've constructed a test mandolin with a removable backplate so we can go into the mandolin and move pickups around with ease, test them in different locations on the soundboard, and test various types of acoustic pickups in different locations within the air chamber. We'll be focusing on this project over the next two months or so, and we will bring you our results - and hopefully some great pickup solutions - when we have concluded our tests and product development.

I would enjoy hearing from you if you have special amplification needs, or if there are specific issues or visions you've had regarding amplification. Email me or let's get a conversation going on our Facebook page.

Our goal is to enhance your luthierie experience and provide you with the best possible support and service, and our focus on amplification is just one more step in that direction.

Over the past 40 years, I've written several articles and columns on the importance of string-break angles. It is an important topic that I explore in my books The Luthier's Handbook and in How To Set Up The Best Sounding Banjo. I believe string-break angle is not just important, it is critical.

String-break angle is the angle the strings make as they pass over the bridge. Too little string-break angle means little or no down pressure on the soundboard (or head in the case of the banjo), and thus, little or no transmission of energy from the strings to the soundboard or head. Too great a string-break angle means excessive down pressure on the soundboard or head, and this can result in the soundboard or head being restricted in its ability to vibrate, which results in little or no energy being generated by the soundboard or head. Somewhere in the middle, there is a sweet spot, where the down pressure from the bridge can properly drive the soundboard or head and make the instrument work efficiently and effectively.

Here is an example of how we evaluated and measured an instrument with a 7� neck pitch and an excessively-high 20� string break angle (the yellow lines indicate the neck pitch and the red lines indicate the string break angle):

It is important to realize that the bridge pushes down with a certain amount of pressure dictated by the string break angle and the gauge of strings. That pressure is met with an equal pressure or force from the soundboard pushing up and a stasis is reached. If that were not the case, the down pressure from the bridge would continue to push in on the soundboard until it imploded. So, there is a relationship between the stiffness of the soundboard and the load imposed on it by the bridge.

String break angle controls the amount of the strings' lateral force that is directed towards the soundboard or head. Banjos are fitted with tailpieces that can be adjusted up or down which, in turn, alter the string-break angle.

I receive at least one email or letter a week in which a luthier describes a mandolin that "sounds dead" or "weak" or one that "lacks tone." Typically, my first response is for them to send me a straight-on side-view photo of their mandolin. Some folks ask "why?" but most respond quickly with a photo or two. Once I receive the photo, I bring it into Adobe Illustrator� so that I can accurately calculate both the string-break angle and the neck pitch. In 95% of the cases where the luthier describes a problem, my intuition turns out to be correct, and I discover that many of the problem instruments have 18� or 19� string-break angles, and when I check the neck pitch, I find that necks are set at 7�, 7.5�, or even 8�.
    
String break angle can be easily measured with a protractor like this:
The ideal string-break angle for a mandolin is 16�.  At 16� a set of D'Addario J73 mandolin strings exerts a down pressure of 45.5 pounds at the bridge. At 17� the load increases to 50 pounds. At 18� the load is 54 pounds, and at 19� the load is just under 60 pounds. Above 19� the down pressure increases exponentially and not only does the amplitude and tonal qualities diminish quickly but severe damage to soundboard, bridge, or both is sure to occur.

A red spruce soundboard carved to the proper graduations and with tone bars attached can withstand a load of about 75-80 pounds before it implodes. So the ratio of down pressure to the failure point is about 1:2. A violin soundboard carved to proper graduations and with bass bar attached can withstand a load of about 100-110 pounds before it implodes (usually on the bass side because the soundpost supports the treble side). The violin bridge - which, by the way, typically has a 15.5� to 16� string-break angle - exerts a down pressure of about 25 pounds that gives the violin a 1:4 ratio.

String-break angle is the result of neck pitch. The higher the neck pitch, the taller the bridge must be and the greater the string break angle. In 99% of the cases where we study tonal or broken bridge-saddle problems that luthiers present to us, the problem is inevitably excessively high neck pitch settings. Original F5 mandolins were set to 5.5� with some measured at 5�. A setting of 5.5� to 6� (which we prefer) is ideal to deliver the timbre and "chop" for a bluegrass mandolin. Anything above this presents an array of problems to the instrument and owner.

We have also seen cases were the neck pitch was correct at 6�, but the neck was set too high in the rim which lowered the body of the instrument and the location of the tailpiece relative to the neck. This lower position of the tailpiece caused the string-break angle to exceed 16�.

One reason we like our V-joint neck connection system is that the neck is aligned and secured in place relative to the crown of the soundboard which, in turn, guarantees the correct string-break angle, instrument after instrument.

In addition to constraining the movement of the soundboard, an excessive string-break angle imposes too great a load on the bridge. The typical two-post Gibson-style bridge saddle is close to its failure point with J74 strings and a 16� string break angle (which impose a load of 49 pounds). String break angles in excess of 16� with these strings presents the bridge saddle with loads it was not designed to handle and often leads to saddle failure.

If you are interested in more about string-break angles, please visit our Addendum webpage for the previously mentioned books. Here you will find photos of how we measure the string-break angle and how we measure the loads along with a chart that shows the loads for a set of J73 strings at strings break angles from 0� to 22�.

 

Siminoff Luthier's Shirt, Men's

For most luthiers, the act and art of binding is high on the list of those tough-to-do things. And, it seems that after someone gets their initial glimpse of the whole instrument, the first detail they focus on is the binding; how well and gracefully the bends are executed, how clean the mitered joints are, and how well fitted the binding is to the surrounding wood parts of the body.

What tickles my fancy is that the binding work on the majority of the instruments made by today's luthiers exceeds the quality of the binding work on the instruments we revere the most: Gibson's Loar-signed F5 mandolins. In essence, many builders have surpassed the artistry of the instruments they inspire to replicate.

There are some tricks to joining and fitting binding miters - the places where binding comes together to make corners - and these relate to ensuring that the two adjoining binding pieces are well glued together and that there are no gaps or voids in the connections.

Gaps can be filled with "liquid celluloid" which is easily made by dissolving celluloid particles in acetone. Simply scrape some celluloid binding and put the pieces in a small dish. Then add a small amount of acetone that will melt the celluloid particles into a celluloid paste. You have only a few minutes to use this paste because the acetone evaporates quickly. So, if you have small gaps that you cannot close, just force a small amount of the paste into the gap; it will melt into the adjoining binding. When it has dried and scraped flush, it will become an invisible part of the binding.

Be especially careful when handling acetone because it is hazardous to breath and highly flammable. Be sure to work in an area that is well ventilated and away from an open flame.

The second trick is to be able to tightly join the two pieces of binding at the outset, and you can facilitate this with small spring clamps whose jaws are bent at right angles. Bending the jaws will help the clamps stay in place better than if the jaws were straight.

Of course, the goal is to prepare joints whose cuts were so well executed that no filler is needed, and to shape them with such precision that only tape - not a clamp - is needed to hold them together while the glue is drying. But, on your way to perfection, liquid celluloid and small clamps can be your best friend.