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Hi
Just wondering if theres a recommended note to tune the soundboard and back to

Tapping my OM soundboard on the bridge plate gives a C note and the back gives a Bflat

I haven't shaved the front braces much yet as not sure exactly what im doing really

Someone told me it should be A for top and Aflat back

I might be on a wild goose chase
Any info please

c & b# are the same note.
This may cause some trouble
Maybe Al Carruth can help ya.
PM him.

Mc

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Mike Collins

Oops meant B flat on back

Are top/back fitted to the sides yet?

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

No not yet Colin

IIRC, the pitches of the free plates are not that important, but the difference between the top and back should be about 2 semitones.
Mr. Carruth uses Chaldini patterns for free plate tuning, but the shape of the modes are more important than the frequencies.

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A man hears what he wants to hear, and disreguards the rest. Paul Simon

Thanks rodger
Sorry music theory is terrible
Whats 2 semitones from c

Cheers

Each fret is a semitone, Bflat is 2 semitones below C.

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A man hears what he wants to hear, and disreguards the rest. Paul Simon

In addition to the pitch changing when the plate is glued to the rim, it will also behave differently when the bridge is glued on. Rodger, was your 2 semitone based on free plate or final strung up guitar? I have yet to get a handle on all of this. . .

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

What Roger said.
I've had a look at the plan - if you followed the bracing dimensions fairly closely, scalloping etc., I wouldn't worry about this for a first build.
The main thing to watch out for is not to have the final frequencies of the back and top the same after the box is closed.
Try to have 1 to 3 semitones separation, with the back higher than the top, it is said to be desirable.
Frequencies can be played with a bit while the guitar is still "in the white"- box all together, and the top frequency predicted reasonably when the bridge is fitted.
The edges of the top can be thinned to drop the frequency, same with the back. Braces can to some extent be worked on.
Dropping the frequencies is a lot easier than increasing them.
I'm sure it will turn out pretty good as per plan, maybe a bit over-braced but so were many first builds, and I'm still playing mine. Not too bad and improved with time.
Just take notes of your impression of the woods, thicknesses, width and height of the braces etc., and you can change things as you feel fit next time. Oh, nearly forgot density of the woods can be very useful.
There will, of course, be a next time?

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Down would be B flat, up would be (EDIT!) D

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Right: you can't predict the assembled pitches of the top and back very well from the 'free' plate pitches.

It's usually a good idea to have the final pitches of the top (in particular) and the back a bit off from scale pitches. If the top comes in exactly at G~196 you could end up with a 'wolf' note at that pitch. Depending on how active the top is, and what else is going on, it might just add an interesting bit of variation, or it could give a 'thumpy' note that is loud with little sustain. A close match can also play hob with the intonation of notes near that pitch. Some folks advocate having the main resonances fall halfway between scale pitches, which helps avoid troubles.

Generally speaking I find that gluing on the bridge drops the 'main top' pitch a bit; it adds more mass than stiffness. You can use that to help fine tune things.

Thanks Colin good advice