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Topic: Compensated Bridge |
Bill Duncan
From: Lenoir, North Carolina, USA
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Posted 18 Apr 2020 11:15 am
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Why has no one built a pedal steel guitar with a compensated tuneable roller bridge?
Move the puller assembly back and put an adjustable roller bridge at the scale length point. As is done with a Bigsby tremolo on electric guitars. |
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Ian Rae
From: Redditch, England
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Posted 18 Apr 2020 11:55 am
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I would worry about chasing my tail.
Am I out of tune or is the thing that's supposed to help me play in tune out of tune? _________________ Make sleeping dogs tell the truth!
Homebuilt keyless U12 7x5, Excel keyless U12 8x8, Williams keyless U12 7x8, Telonics rack and 15" cabs |
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Franklin
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Posted 18 Apr 2020 1:44 pm
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Jackson Guitars - David Jackson has made one.
Paul |
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Bill Duncan
From: Lenoir, North Carolina, USA
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Posted 18 Apr 2020 2:34 pm
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Thanks, Paul, I knew I wasn't smart enough to be the only one to think of that. |
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Doug Earnest
From: Branson, MO USA
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Posted 18 Apr 2020 3:54 pm
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Paul, have you tested David Jackson's compensated bridge and if so would you care to comment if there was a noticeable (improved) difference in the traditional design? |
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Michael Hill
From: Arizona, USA
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Posted 18 Apr 2020 5:32 pm
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This is a really interesting idea.
I wonder if compensation is not as important for slide guitar as there's no pressing down and stretching the string to contact a fret.
Also, E9 may have 10 strings but the range of notes on the open strings is smaller than the range of notes on a standard tuned 6 string guitar. Less range should mean less compensation needed. |
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Donny Hinson
From: Glen Burnie, Md. U.S.A.
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Posted 18 Apr 2020 5:46 pm Re: Compensated Bridge
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Bill Duncan wrote: |
Why has no one built a pedal steel guitar with a compensated tuneable roller bridge?
Move the puller assembly back and put an adjustable roller bridge at the scale length point. As is done with a Bigsby tremolo on electric guitars. |
I'm not completely sure that would help. The Bigsby pulls all strings equally, and all at once. Pedal steels don't work like that. |
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Franklin
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Posted 18 Apr 2020 6:11 pm
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An adjustable bridge allows instruments to be tuned to ET....All ET tuned instruments have a different scale length per string to guarantee the same variation as the hand moves up the fretboard. Take a guitar and make the bridge absolutely straight so that every string has the same exact string length like the steel.....Now play chords up the neck and see how bad it drifts out of tune.. |
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Ian Rae
From: Redditch, England
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Posted 19 Apr 2020 1:23 am
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If I feel a chord is slightly off I can often improve it by slanting the nose of the bar towards the bridge, never the other way. This represents the same slant that is provided on a fixed 6-string guitar bridge or that you end up with on an adjustable one.
But on a fretted instrument the amount of string deflection is a known constant for each note on the fretboard - on the PSG it depends on the bar pressure, which is emotional. _________________ Make sleeping dogs tell the truth!
Homebuilt keyless U12 7x5, Excel keyless U12 8x8, Williams keyless U12 7x8, Telonics rack and 15" cabs |
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Doug Earnest
From: Branson, MO USA
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Posted 19 Apr 2020 12:54 pm
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I'm well aware of compensated bridges on other instruments and the reasons for having them, I would just like to know who has actually played a pedal steel with such a bridge and hear about their experience. |
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Jerry Jones
From: Franklin, Tenn.
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Posted 19 Apr 2020 1:12 pm
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Wouldn't the compensation required change as soon as you press a pedal changing the tension and the pitch? Maybe a small amount? And how much compensation for that low A on C6th? _________________ Jerry Jones |
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Ron Pruter
From: Arizona, USA
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Posted 19 Apr 2020 6:50 pm
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I, like Doug E, would like to hear about this. "All" that would be needed would be to have the ability to pull the axle for each individual changer finger forward or backward. (Actually left or right as seated) I know my 10th and fifth strings at the 12th fret are way off. Changing to a lighter string on the flatter of the two would probably help but,,,, I don't want to. _________________ Emmons SKH Le Grande, '73 Fender P/J bass, Tick tack bass, Regal high strung, USA Nashville 112. |
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Georg Sørtun
From: Mandal, Agder, Norway
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Posted 19 Apr 2020 6:58 pm
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Not a compensation bridge as such – at least not the kind you are thinking of, but back in the days I found that angling the bridge gave my old Dekley purer tones, especially for the low strings.
I tested by pushing the original changer pillow forward for longer thick strings, and as these tests were so obviously successful I had new pillows made along with new changer axle when I put a new neck on that steel.
The 10th string spans 3mm longer than the first string, which – simply speaking – made the vibrating lengths of those strings more equal.
As the axle still makes the bridge/changer angle fixed across the strings, there is no "perfect solution" here. It is just audibly better with that slight angle than the regular, 90 degree, bridge/changers that Dekley had, and all other PSGs have.
The slight angle is also not so much "out of line" that it creates problems with pull-rods or otherwise. |
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Bill Duncan
From: Lenoir, North Carolina, USA
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Posted 20 Apr 2020 3:36 am
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I am with some other folks in that I would like to know how David Jackson's project turned out.
Georg Sortun has already done some bridge compensation. Much as on flat-top acoustic guitar bridges. |
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Ross Shafer
From: Petaluma, California
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Posted 20 Apr 2020 6:54 am
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Ian Rae has it right:
"But on a fretted instrument the amount of string deflection is a known constant for each note on the fretboard - on the PSG it depends on the bar pressure, which is emotional."
Bridge compensation is largely dependent on how much bend is required to depress a string to the fret or fretboard (as on a fretless bass). On Steel guitars we do not have the same "known constant" when "fretting" a note. In my opinion (yeah I know, everybody has one....). Trying to compensate for the not so constant bar pressure/string deflection on a steel guitar would be at best a ponderous exercise with minimal benefit and at worst a waste of time. |
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Erv Niehaus
From: Litchfield, MN, USA
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Posted 20 Apr 2020 7:20 am
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Kind of like trying to teach a pig to sing!
Erv |
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Ross Shafer
From: Petaluma, California
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Posted 20 Apr 2020 7:50 am
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not so sure Erv.....right now a singing pig would get a lot of people's attention and produce lot's of smiles! |
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Doug Palmer
From: Greensboro, North Carolina, USA
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Posted 20 Apr 2020 8:22 am Tunable bridge
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I always questioned how can a guitar or steel guitar can be in tune up the neck when the spacing at the nut is not as wide as it is at the bridge or changer. Assuming strings 5 and 6 on a steel go straight to the changer then strings one and ten should have a slightly longer scale. I asked Big Ron about this and didn't get a good answer. I guess that is why flat top acoustic's with a flat bridge always sound out of tune up the neck to me. _________________ Emmons D-10, ST-10,LD-10 III, NV-112,Fender Deluxe Reverb. Authorized wholesale dealer musicorp.com! |
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Georg Sørtun
From: Mandal, Agder, Norway
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Posted 20 Apr 2020 8:41 am
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Ross Shafer wrote: |
Trying to compensate for the not so constant bar pressure/string deflection on a steel guitar would be at best a ponderous exercise with minimal benefit and at worst a waste of time. |
Varying that pressure is part of how I fine-tune while playing, so would be counterproductive if someone found a way to compensate for it |
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Gary Cosden
From: Florida, USA
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Posted 20 Apr 2020 8:56 am
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It is not possible to have perfect intonation on any stringed instrument. The best approach any manufacturer can take is to minimize every conceivable way in which intonation can be "off". Compensated bridges on guitars don't make for perfect intonation no matted how carefully they are set up. Compensating nuts, as an addition to a compensating bridge, are an option for electric 6 strings and seem to help out the plain 3rd strings some in the lower positions which a compensating bridge alone does not do.
It seems to me that George Sortun's approach shown above makes a great deal of sense. While bar pressure is an unknown factor, it is a given that the heavier the string gauge the greater amount of compensation is required. In a way it's reminiscent of a acoustic guitar bridge. |
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Bobby D. Jones
From: West Virginia, USA
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Posted 25 Apr 2020 3:41 pm
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I went to a friends house a few months ago. He called and said a guy he knew was bringing a Jackson Steel to his shop.
I had never seen a steel constructed the way this one was. It had a changer with RAISES only. The LOWERS was on the key head, The keys was mounted on plates that was controlled from under the steel, The key shaft was the pivot point on the lower. It turned the key mounting plate from under the steel, To lower the string.
In looking at the changer, The fingers looked like a regular changer finger on the top, Except there was a notch cut in the front of the finger, Cut with a small round mill cutter. The string did not roll over the finger, When the string was raised, It tightened acting as a straight pull lever. Not rolling like a finger. By cutting the notch deeper into the front of the changer finger a specified distance for each string would change the intonation on each string.
Did not have much time to look at the guitar, Would like to go back and look at it from an engineering view, Not as a musician. |
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Ian Rae
From: Redditch, England
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Posted 26 Apr 2020 12:17 am Re: Tunable bridge
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Doug Palmer wrote: |
I always questioned how can a guitar or steel guitar can be in tune up the neck when the spacing at the nut is not as wide as it is at the bridge or changer. Assuming strings 5 and 6 on a steel go straight to the changer then strings one and ten should have a slightly longer scale. I asked Big Ron about this and didn't get a good answer. |
Ask a mathematics teacher or look out an elementary textbook of geometry. Even though the strings aren't parallel, the bar still divides them in the same ratio (which is what determines pitch). _________________ Make sleeping dogs tell the truth!
Homebuilt keyless U12 7x5, Excel keyless U12 8x8, Williams keyless U12 7x8, Telonics rack and 15" cabs |
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Bill Duncan
From: Lenoir, North Carolina, USA
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Posted 26 Apr 2020 3:21 am Re: Tunable bridge
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Ian Rae wrote: |
Doug Palmer wrote: |
I always questioned how can a guitar or steel guitar can be in tune up the neck when the spacing at the nut is not as wide as it is at the bridge or changer. Assuming strings 5 and 6 on a steel go straight to the changer then strings one and ten should have a slightly longer scale. I asked Big Ron about this and didn't get a good answer. |
Ask a mathematics teacher or look out an elementary textbook of geometry. Even though the strings aren't parallel, the bar still divides them in the same ratio (which is what determines pitch). |
Funny you should say that Ian. I have a daughter in fourth grade and I have been trying to explain working with fractions. To no avail I might add. We have to take the weeks lessons to school on Mondays and get new assignments. I tried talking to her teacher about the fractions and the teacher said, "as long as she has the right answer, the way she got it is up to you and your daughter".
I suppose playing in tune is about the same. |
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Georg Sørtun
From: Mandal, Agder, Norway
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Posted 26 Apr 2020 5:46 am
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Will add that; as I tested to find the "optimal" bridge angle, I also went through a check of "why that is", and also compared to the compensations I have adjusted to on my regular guitars and bass. Here is some of what I found…
1: no strings vibrate from the exact bridge-points, but from a point on the sting a given length away from that exact point (used microscope and other tools to determine how far down the string "free" vibration started). Wound strings did (of course) start vibrating further from the bridge-point – except that a plain 6th had that vib-start point further down than a wound 6th of same gauge. It is how rigid the string is that matters for this distance, not the string-gauge as such.
2: As that particular PSG had/has an unusual tuning with thicker 7th and 9th strings in between the regular E9 strings, I grooved the bridge/changer roller to lower those stringe to level them with the others. If I made those grooves "V" shaped the thicker strings would not intonate properly, but when I "U" shaped the grooves and made them somewhat wider than those thick strings – no side-support for the strings – they intonated fine along with the other strings up and down the neck. Again, all intonation tested by hearing, and vib-start points checked with microscope. Those two "odd" thich strings' vibration lengths are actually longer than the regular 10th string, despite appearing to be a tiny bit shorter when looking at the bridge/changer from above.
(On another PSG, same brand, that I prepared for that "odd" tuning much later, I did not bother to groove the bridge-rollers for those thicker strings, and consequently they have an increasing "intonation-error" with the bar nearer to the bridge both because they are too high and because their vib-points are further from the bridge. No problem to me )
3: I made similar wide "U" shaped grooves in the nut-rollers for those two thicker "in-between" strings. As there is hardly any movement in those rollers during changes for those strings, I made those grooves excentric for half the roller-radiuses, which means I can adjust string-height and affect vib-point at that end slightly. I can also level them to regular string-gauges by turning the rollers 180 degrees, if I so choose in the future. |
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Craig Stock
From: Westfield, NJ USA
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Posted 27 Apr 2020 11:01 am
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Chris Templeton asked me to post this photo and this responce.
"Ned Steinberger made this second compensated for my Sierra".
_________________ Regards, Craig
I cried because I had no shoes, then I met a man who had no feet.
Today is tomorrow's Good ol' days |
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