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Hi

I have a 25.4 scale neck (its actually 25.3) which I am fitting to my OM kit.

What is the process of calculation for compensation and final location of the bridge , my bridge has the saddle slot already pre routed

John

I made a tool...modeled after the StewMac Saddlematic. Here is the link to the instructions...

http://www.stewmac.com/shop/Tools/Speci ... ns#details

I also made a copy of the stewmac saddlematic and followed their instruction and have had no issues using it on my 7 completed guitars and the intonation was very easy to set after setup.

Fred

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Fred Tellier
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My saddle slot is already routed so I would have to use either the treble or bass a reference.

I'll make one up this weekend and see how close it is.

John

In theory the bridge should be the same distance from the 12th fret slot as the nut, so all you have to do is measure, in theory. In theory there is no difference between theory and practice, but in practice there is.

The main issue is that when you fret a string you displace it, and thus stretch it a bit, which raises the pitch. You compensate for that by moving the bridge a little further down on the top than it 'should' be in theory. Just how much further depends on a whole bunch of variables, some of which you can't know in advance.

In practice, the high E string will need the least compensation, and the low E the most, usually. Adding a small amount of compensation to the high E side and using a slanted saddle slot generally gets you pretty close to right. If I'm using a 1/8" saddle I'll set the bridge so that the front edge of the slot on the high E side is at the 'theoretical' distance from the 12th fret. Rounding over the saddle top gives about 1/16" of compensation, and that's usually about right for me. Placing the bridge so that it's front edge is perpendicular to the center line of the guitar gives about the correct slope to the slot. I also find it helps to rout the slot at a back angle, as seen from the side, so that raising and lowering the saddle also moves the contact point a bit to preserve the intonation. Rick Turner decided that a 9 dgree back angle was about right, and that seems to work well for me too.

Wow, route the saddle slot at a 9 degree angle.......I wouldn't have guessed it required that much slant. Thanks for that info Al. Does the slant angle change between using nylon and steel strings? (I assume it wouldn't)

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Formerly known as Adaboy.......

Based on the feedback I am going to set my saddle at half the scale length + 1/16 of an inch on the high e side - as the slot is already cut I will have to live with whatever the distance is on the bass side - I am presuming it will be about 5/32 of thereabouts.

John