Another prototype

[Graham McDonald]

A second prototype for a planned mandolin quartet of two mandolins, mandola and mandocello. The body of this one is a little larger than the first, around 6mm longer and wider as well as a little deeper. This one is almost all Australian timbers, a King Billy pine soundboard, Australian blackwood for the body and neck, gidgee for the fretboard with the head overlay of blackwood and mulga. The soundboard has been carved to 3mm all over with a 2x2 King Billy/carbon fiber lattice in the centre to stiffen it up. The neck bolts on through the heel into a t-nut on the inside of the neck block. This is the second soundboard on this mandolin. The first was spruce with tone bars and a soundhole up on the upper bass side. It sounded horrid so it was replaced. It is a prototype after all. Thanks to the wonderful Claudia and Claudio Paggelli from Switerland who have allowed me to adapt their beautiful guitar design to this family of mandolins.

[Frankdolin]

Love it! Can't wait to hear this group in action.

[tom.gibson]

I really like this Graham - the design, the wood selection, the quartet ambition, everything. I look forward to seeing its siblings.

If I remember your previous carbon bracing experiments right, it seems like you've been shrinking the size of the lattice until it now takes up just the centre of the soundboard under the bridge. Have you found the right balance between centre stiffness and perimeter flex? I suppose that means, are you pleased with the sound?

[j. condino]

Lookin' good Graham! Once you move from building individual instruments to trying to create them as a complimentary quartet, it opens up all kinds of new possibilities and makes the building process fun. (Be glad you don't have to build a bass to match it!)

[Graham McDonald]

I think this one is still a little too stiff. The free-plate tap pitch was around where I thought it should be, but there is a metallic edge to the sound and I think a strong resonance around the b on the e string. I need to do some analysis on where the soundboard resonances are in comparison to an X braced soundboard. As the classical guitar makers have found, the CF lattice bracing can be quite tricky to get right, and it may just not be suitable for mandolins with carved soundboards. I should get this out to some of the local players for a few days to get some feedback.

Cheers

I really like this Graham - the design, the wood selection, the quartet ambition, everything. I look forward to seeing its siblings.

If I remember your previous carbon bracing experiments right, it seems like you've been shrinking the size of the lattice until it now takes up just the centre of the soundboard under the bridge. Have you found the right balance between centre stiffness and perimeter flex? I suppose that means, are you pleased with the sound?

[Davy Simpson]

Damn, that looks fantastic! Lovely curves.