Finally got this CBG done and strung. The problem is one of two things(in my mind anyway) 1_the strings (Southbound) 2 wound 1 not. Tuned EGg (on edit GDg)
2scale 25 1/2 everything was remeasured frets. At 25.5 12th fret all 3 strings run slightly on the sharp side. Moved bridge toward tail 16th" +/- G & D dead on, g runs more to the sharp side. Should I restring with a wound set and start over? I've never had this problem before so it's new to me. The gitty has nice tone and volume but that g sounds off to me when I pluck the open string. But the tuner says it's dead on. So what in the Sam hill is going on?
Thanks KD
Replies
Might be the nut. The action might be too high at the nut which makes the first two or three frets run sharp since you are pushing the string down too far when fretting. Also the string may be leaving the nut behind the fretboards edge. From the middle of the nut instead of the edge nearest the fretboard. If it’s an electric guitar the pickup poles may be too close to the string which pulls the string a little out of tune. At the twelfth fret if the action is too high the string will pull sharp. The bass string may need to be saddled toward the tail piece a little (called a compensated bridge). Setup is tricky. I use my Snark tuner and try the main frets (3,5,7,12) looking for sharps and flats till I adjust the nut and bridge to be dead on in every position. Just finger pressure on the fretting can change the tuning. Don’t clamp down too hard.
When I place my bridge on the CBG top(usually a bolt for CBG's), the middle of the bolt(center string for 3 or between middle 2 of 4) is right on at the scale length from the fretboard side of the nut. Low string side end of bridge bolt is 3mm away from end of fretboard and high string side end of bridge bolt is 3mm towards the fretboard.
This formula has worked everytime on my CBG's and other guitars as well.
As someone else mentioned, string height can pull the string sharp while fretting if the initial string height is too high.
Hi Paul, I'll buy back in just for the sake of constructive discussion. I am a bit confused by your explanation above. Correct me if I have misunderstood this.
You say to shorten the first string whilst lengthening the bass side string. Wouldn't this make the first string shorter than the scale length?
If I look at my reasons for lengthening fretted instrument strings, it is due to the Equal Tempered Scale used, and the exact fixed positioning of the frets. So, as we know tuning the strings to pitch with the saddle at the scale length [no compensation] we have perfect pitch on all strings. But due to "other factors" [already discussed] the different pitches heard as we fret up the fingerboard do get sharper. So to compensate we make certain strings including the first string longer, so lowering the pitch, and compensating for those "other factors".
I find it hard to see why a string would need to be moved forward to that degree unless the bridge was less than perfectly positioned. It is hard to be spot on with a straight saddle, I know, and it might be due the use of a wide bolt for a saddle. Interesting.
When I fit Tunamatic style bridges I work on/around the post positions centred on the scale length but moved back 2mm on treble side and 5mm on bass side, to get full adjustment from the saddles both ways. But before drilling holes I check the position using my strobe tuner.
What am I missing?
Taff
The strings will intonate at different lengths. A acoustic bridge assembly will be straight, but the bone bridge piece will sit in the assembly at an angle(bass side longer and treble side shorter.
On a CBG using a bolt/screw or solid bar type bridge it will need to be angled in similar fashion.
A Gibson type bridge is angled as well even though the saddles can be moved back in forth.
Fender puts their bridge assembly straight because the saddles have extra length screws to adjust for intonation.
The saddles are adjusted in an angle. So a CBG solid screw or similar type bridge will need to follow that angle. Gibson will move the bass side back 3mm, but some people have problems with those high/treble strings because the saddles wouldn't adjust forward enough. So I move the treble side forward 3mm to get those strings were they need to be.
Thanks for the reply Paul, I understand what you are saying.
Here is a diagram I made that may explain my thoughts a bit clearer on setting acoustic intonation. You can see that the saddle is angled away from the scale length line but the treble side is not moved forward, it stays on or behind that imaginary line.
Cheers Taff
Got it. I do it like your NO example and it works great for the Gibson style bridges by giving a little extra adjustment if needed, but still work if not needed.
For a fixed solid screw/bolt for a CBG, it works for me for intonation up to the 12th fret. One reason that my way works may be that when tuning my guitar, I tune the open strings first and then check the 12th fret and do any compensations that may be needed?
Best thing to do in that case would be to draw a little line and place the screw/bolt on the line, then move the sides to where you need them to find the right spot while doing the intonation, make a small mark on ends for the correct placement and then attach to the top in whatever way you intend to attach the bridge. ;)
I've been using guesstimate/looks right method and it servers me well, until this build. Nothing I did worked. So I went back and reworked everything ( cut nut deeper, changed back angle and the string) basicly lowered action. It sounds awesome. Its been delivered and they're happy!
Thanks for the tips and advice everyone, greatly appreciated! I'll remember the 3mm trick. I've been curious about a formula, one of the fret calculators has the information, but if you don't know, ' you don't know' what to do with it!
I found the formula when looking up on Google: How to mount a Gibson style bridge? Gibson does the 3mm on the bass side, but not the treble side and people often complain of not being able to move it forward enough for intonation, so I adapted the 3mm forward on the treble side. So for a fixed bridge without movable saddles it works great.
Changed out the high g from a 9 to 11 and started over. So far so good! Thanks everyone hopefully it sticks.
Hi Hooch, the actual bridge is not skewed but the saddle itself is angled to give strings compensation.As a rule and guide with medium strings on a six string guitar, measure the scale length and add a 1/16" to the first string and 3/16" to sixth string. Then of course this is fine tuned to suit action height.
Taff
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