An opinion please on bowl-backed mandolin

[Pelican tree]

Hi, I would very much appreciate any information anyone might have on this bowl-backed mandolin. It has no markings on it other than a gold star on the headstock. I am in the process of restringing it, with the hope of learning how to play it. Thank you very much. Paul

[DavidKOS]

I must admit that I have not seen an adjustable bridge like that. Somewhat above average quality otherwise, looks USA made (Chicago?)

I'm looking forward to what the experts have to say.

[pops1]

You may know this, but these require extra light strings to avoid damaging the instrument.

[Pelican tree]

Thank you David for your reply.

I was surprised to find that the bridge was not attached to the sound board and is actually held in place by the strings. This means that it can be placed in different positions. If I place it further towards the tailpiece, it will lower the action. Now I am wondering if the purpose of a floating, adjustable bridge is to raise or lower the action.

I am new to mandolins and found this among my father’s possessions. He is 87 years old and cannot remember where it came from.

One interesting feature is that the body seems to have been carefully constructed and neatly finished, however the headstock seems very roughly made with the holes for the pegs not matching very well.

Cheers from Paul

[Pelican tree]

Hi pops1, no, I didn’t know. Thank you very much.

Today I bought a set of new strings. They’re D’Addario EJ75, 0.0115 - 0.041.

Given that they’re described as Medium/Heavy Gauge, should I choose a lighter set? Would D’Addario EJ73 Mandolin Strings, Phosphor Bronze, Light, 10-38 be light enough?

Thanks, Paul

[Bob A]

Hi pops1, no, I didn’t know. Thank you very much.

Today I bought a set of new strings. They’re D’Addario EJ75, 0.0115 - 0.041.

Given that they’re described as Medium/Heavy Gauge, should I choose a lighter set? Would D’Addario EJ73 Mandolin Strings, Phosphor Bronze, Light, 10-38 be light enough?

Thanks, Paul

They'll destroy the mandolin quickly.

Take a look at these:http://www.juststrings.com/ghs-a240.html

Much more suitable.

[Bob A]

Thar bridge is far from original, and should be replaced with something traditional, that was made by a luthier, not a machine shop.
I don't think having two major pressure points is good for the top of the instrument; the pressure ought to be equalised across the top. The bracing of the mandolin is not made to deal with the sort of narrowly focused pressures.

BTW, bridges on most mandolins are not attached to the top. They're supposed to be movable.

[Pelican tree]

Terrific, thank you very much Bob!

It seems I really do need to be careful. I really don’t want to cause any damage. Fortunately, so far I have only taken the old strings off and not attempted to attach the new ones. Whew! I think I have some learning to do.

Cheers from Paul.

[Pelican tree]

So more like a saddle/bridge on an acoustic guitar, or on a violin, but moveable? Is it moveable so as to adjust the action?

Perhaps, I should be visiting an instrument maker before I damage it?

[pops1]

Looks like a nice instrument, since you need a bridge anyway a trip to a luthier may be in order. Enjoy it's a long jun ride.

[Pelican tree]

I understand now, after looking at various bridge designs on the web. It seems I should replace the existing incorrect bridge with a mandolin bridge made of wood that distributes the force over a larger area. Looking at the many different designs, it appears that some bridges have height adjustment. I will need to read up. I’m out of my depth. Thanks for your help.

[Pelican tree]

Thanks pops1.

If not for the help I’m receiving from this forum, those new heavy strings would have been on tomorrow and the metal bridge would have been applying an even higher amount of pressure at two points. Interestingly, I can see two circle marks where the bridge has already compressed the sound board.

This little mandolin has sat in its case for fifty years and so thanks to this forum, I will stop my DIY approach and now find a luthier.

[bennyb]

Part of the reason the bridge is movable is historical(i.e. tradition) probably, but it does allow the player to adjust the position for best intonation. For a given bridge and set of strings, there will be one best position, but that best position for a different setup may be very slightly different. Take the distance from the fretboard side of the nut to the middle of the 12th fret and double that for the theoretical scale length(distance from nut to bridge), the actual distance will be a skosh more(e.g. 1/16") measured to the short side of bridge, typically the e string side. Once you're at that point, final adjustment by tuning the 12th fret harmonic and 12th fret fretted note equal. Some compromise is typically required 'til you get all 4 courses as near as possible.

[rcc56]

Today I bought a set of new strings. They’re D’Addario EJ75, 0.0115 - 0.041.

Given that they’re described as Medium/Heavy Gauge, should I choose a lighter set? Would D’Addario EJ73 Mandolin Strings, Phosphor Bronze, Light, 10-38 be light enough?

Thanks, Paul

The EJ75 set will ruin any mandolin that was made before WWII, whether it's a bowlback, flat back, or a fully carved Gibson.

For that mandolin, .009/.013./.022/.034 or close to that would be suitable. The Ernie Ball 2323 or the GHS A240 that Pops mentioned are prepackaged sets that should be easily available.

[Jim Garber]

Late to the dance here. Ony thing I can add is this one resembles others made by (or for) Lyon & Healy. Headstock and pickguard shapes resemble their Washburn line of mandolins from the early 20th century.

[Mark Gunter]

If I place it further towards the tailpiece, it will lower the action. Now I am wondering if the purpose of a floating, adjustable bridge is to raise or lower the action.

Hi Paul! I think you should carefully read bennyb's post, and understand that floating bridges allow for adjustment of the intonation. They shouldn't be slid forward or back to adjust the action. Moving the bridge forward or back will change the scale length and thus affect intonation!

"Adjustable" mandolin bridges, in addition to floating (moving backward or forward) also have the feature of being able to raise or lower the height of the saddle, to help with the action.

I thought I'd chime in just to make it clear that you should not slide the bridge forward or backward in an attempt to adjust the action, rather you should set the intonation as close as possible as per bennyb's post.

[LadysSolo]

That's a nice looking mandolin, enjoy learning to play it!

[Pelican tree]

Part of the reason the bridge is movable is historical(i.e. tradition) probably, but it does allow the player to adjust the position for best intonation. For a given bridge and set of strings, there will be one best position, but that best position for a different setup may be very slightly different. Take the distance from the fretboard side of the nut to the middle of the 12th fret and double that for the theoretical scale length(distance from nut to bridge), the actual distance will be a skosh more(e.g. 1/16") measured to the short side of bridge, typically the e string side. Once you're at that point, final adjustment by tuning the 12th fret harmonic and 12th fret fretted note equal. Some compromise is typically required 'til you get all 4 courses as near as possible.

Thank you very much Benny! Your post prompted further reading and now I understand that the distance to the 12th fret is half the scale-length and that this determines the initial placement of the bridge, so that the pitch at the 12th fret is an octave higher than that of the open string. I'm finding this very interesting. I will pick up digital tuner to help. I suspect it might take me some practice to sound the harmonic.

Your instructions are terrific, but I do have a question. When making the fine adjustments, should I loosen the strings a little before moving the bridge, or can the bridge be moved slightly without having to loosen them?

[Pelican tree]

The EJ75 set will ruin any mandolin that was made before WWII, whether it's a bowlback, flat back, or a fully carved Gibson.

For that mandolin, .009/.013./.022/.034 or close to that would be suitable. The Ernie Ball 2323 or the GHS A240 that Pops mentioned are prepackaged sets that should be easily available.

Thank you rcc56! Although my local music store doesn't have them, I've been able to find an online store in Australia that sells the GHS 9-32 Ultra Lights. It's a real relief that I didn't get around to installing the EJ75s. I really appreciate all of the terrific advice.

[Pelican tree]

Late to the dance here. Ony thing I can add is this one resembles others made by (or for) Lyon & Healy. Headstock and pickguard shapes resemble their Washburn line of mandolins from the early 20th century.

Hi Jim, this is exciting to hear. Thank you! I am definitely curious to learn about the history of this mandolin.

I've now started to read about Lyon & Healy and to look at images. They definitely look very similar. My father's mandolin is taking me on quite an adventure, given that I am new to mandolins, and to instruments in general. Perhaps Washburns were being exported from Chicago to Australia.

I am wondering, was it common at the time for the manufacturer not to engrave their name or logo into the headstock? Also, would there have been a paper label on the inside of the mandolin that has come unstuck at some stage? I have carefully looked inside and there is nothing there.

[Pelican tree]

Hi Paul! I think you should carefully read bennyb's post, and understand that floating bridges allow for adjustment of the intonation. They shouldn't be slid forward or back to adjust the action. Moving the bridge forward or back will change the scale length and thus affect intonation!

"Adjustable" mandolin bridges, in addition to floating (moving backward or forward) also have the feature of being able to raise or lower the height of the saddle, to help with the action.

I thought I'd chime in just to make it clear that you should not slide the bridge forward or backward in an attempt to adjust the action, rather you should set the intonation as close as possible as per bennyb's post.

Hi Mark, thank you very much for your advice.

At first, I did think that the reason the mandolin's soundboard was constructed with two angles was to lower the action by moving the bridge back and forth, but now I understand that this makes absolutely no sense at all, given that the 12th fret must be the half-way point. So, I'm not sure why the soundboard is not a single flat surface.

There's so much more to this mandolin than I'd imagined!

I have been searching for a suitable bridge and have noticed that some do have height adjustment. I'm not sure if I should choose a bridge like that, or focus on one that is traditional for the instrument. I've also noticed that some bridges are described as compensated.

I'm surprised at now many different bridges there actually are. Also, I am still learning about the importance of action. I can see that the nut determines the action at the first few frets, and that this quite low. But how high should the bridge be? What should the action be at the 12th fret. This I don't yet know.

Cheers from Paul

[Pelican tree]

That's a nice looking mandolin, enjoy learning to play it!

Thank you LadysSolo, I am really looking forward to playing it! I doubt I can afford lessons and so will be learning from the web. Should be fun.

[bennyb]

should I loosen the strings a little before moving the bridge, or can the bridge be moved slightly without having to loosen them?

Well, you seem to be moving very quickly, Pelican, you'll probably be ahead of me this time tomorrow. Since we're talking about a bowlback here, you better listen to someone better acquainted with them, all my experience is with carved archtop mandolins. But if I had to say one or the other: No, don't move it under full tension. Re the harmonic, you don't have to play the harmonic; if using a tuner, it should show e open string, for example, dead on e, and e at the 12th fret the same(of course, it will actually be one octave higher). All this info will be much clearer after you've done it a few times(about where to draw the line between perfection and practicality).

There are a number of Mcafe members in Oz, so if you mention your general location, there may be someone local who can assist . Good luck.

[Bob A]

The bend (cant) in the soundboard of Italian-style bowlbacks is there to enable a greater downward pressure on the bridge, and thus greater volume. The shape of the soundboard is such that it also arches downward from the center line, so that the strain on the top is not taken by the bracing alone, but also by a sideways thrust against the outer rim of the bowl. Due to the shaping, the whole structure is involved in distributing the strains involved.

There are a couple basic styles of bridge for these instruments. Some have a slot made to hold a saddle, usually ivory, bone or metal wire. This style has slots cut in the wood of the bridge behind the saddle, which serve only as string spacers. Sometomes the saddle is intonated a bit.

The other style has the intonation cuts carved into the bridge itself, the notches for the strings cut into the intonated sections of the bridge.

Bridges are usually pretty low, and not particularly massive. Of course, they are fitted to the curve of the top at their ideal location. Good idea to have a professional do this, it'll save time and aggro.

Action is generally about 2mm over the 12th fret. While the scale is approximately double the distance from the nut to 12th fret, this is not exact, due to factors like fretting the string at fret 12, which changes the tension of the string as well as the length of the vibrating section. Get the setup done by someone who knows how. They might also want to dress the frets, and verify that the neck joint hasn't been buggered by heavy strings. FYI, neck surgery on a bowlback is complicated, expensive and not always successful, not unlike the same procedure in humans.

[Graham McDonald]

The bridge is German and are sometimes found on between the wars mandolins. A little odd to find it on an American made bowlback.

Cheers