9th/10th string gauge

[John Morton]

Would someone please recommend an appropriate gauge for the low C strings on a 10 string mandolin, to complement a Daddario EJ74 set?
thanks

[Tobin]

Best bet is to look at D'Addario's mandola sets and find the set that has similar gauges for the G, D, and A strings.

Their EJ76 set has CGDA gauges of: .052, .035, .025, and .015

Their EJ72 set has CGDA gauges of: .049, .034, .023, and .014

Given that EJ74s have GDA gauges of .040, .026, and .015, it's going to be more comparable to the EJ76 set (though still a tad heavier on the G and D strings than the mandola set). Were it me, looking for a C string to sort of match the gauges of the EJ74 set, I'd probably go with a C string in the .052 range.

[John Morton]

This is puzzling to me. I was thinking somewhere around .050 to .052. But if .052 works for C with a mandola scale, why would .052 be optimal for the same pitch with a mandolin scale? I have always just tried strings until it feels right, but was hoping to hear from someone who plays one of these things.

[Tobin]

Good question, and I wouldn't know about adjusting for scale length. I was just going with sets that already somewhat match the gauges you are using. I would think that they picked those combinations for balance across the strings.

[Tom Wright]

My 10-string is slightly long at 14.25", and it works fine with .050 or .052, although I like lighter strings to protect the neck that lacks an adjustable truss rod, so I use .047. On my 14" electric 5-string I like a fat .056. I would go for the .052 to match .011 on the E. Who made your 10-string?

[John Morton]

This is something I'm making. It's meant to be a bandolim (the Brazilian shape), and since I've never seen any sign of an adjustable truss rod in any Brazilian instrument, I was just going to make a really stiff neck and keep my fingers crossed. There will be a steel bar under the fingerboard.

[Graham McDonald]

Finding the right string for the C course might well involve a bit of trial and error. There is a string tension calculator on my website which should give a starting point if you want to work to a specific tension thought something like a .052 should be around you want. Instruments can sometimes be unpredictable in what string works best. You might also be betterl off to use a 1/2" x 1/4" carbonfiber bar in the neck rather than a piece of steel, which will add a lot of unnecessary weight.

Cheers

[John Morton]

This is going to be made of brass, so a few ounces are not an issue. The player will just have to use a strap. Carbon fiber is a great weight saver, but it is expensive and not as stiff as steel of the same cross section. Also, neck mass contributes greatly to sustain. Needless to say, for this project everything is trial and error!

[Mandobart]

I play a 17" 10 stringer with octave pairs on the C, G and D.
C1 - .045, C2 - .023, G1 - .036, G2 - .018, D1 - .022, D2 - .011, both A's - .014, both E's - .010