kmwaters - Posted - 01/19/2012:  09:00:02

Siminoff sells Brazilian Rosewood fretboards and lists them at 26 1/4 in length.  My Gibson specs say the board is 26.4.  So if someone wants to copy the Gibson configuration, they can't with this length, can they?

Can anyone tell me why they differ and what difference it would make on the banjo?  Thanks.

OldPappy - Posted - 01/19/2012:  09:33:24

26 1/4 is fractional = 26 and one fourth of an inch.

26.4 is decimal = 26 and four tenths of an inch which is only slightly longer.

I would contact Siminoff and ask just how accurate that measurment is.

Often these things are not that precise.

The only precut fretboards I have bought were from Stewmac, so don't know about Siminoff's, but in my limited experience with precut fretboards, they are usually just a bit oversized, which I assumed was to allow for fitting.

uncle.fogey - Posted - 01/19/2012:  09:33:25

Gibsons have a "scale length" of 26 3/8".  The length of the fingerboard is less than 20".  

A piece of rosewood 26 1/4" long would be long enough to make a Pete Seeger longneck fingerboard, OR, you could get your Gibson length fingerboard out of it, and split the remainder of the piece into a bookmatched peghead veneer.

kmwaters - Posted - 01/19/2012:  09:48:10

Right you are!  Never paid attention to this before.  Just measured and the ESS fretboard is 19 1/8, so the specs they list has to be the board they start with.  

OldPappy - Posted - 01/19/2012:  10:06:46

I feel silly for not realizing that. I was too wrapped up in the math.

rudy - Posted - 01/19/2012:  11:28:55

quote:

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Originally posted by kmwaters



Right you are!  Never paid attention to this before.  Just measured and the ESS fretboard is 19 1/8, so the specs they list has to be the board they start with.  

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 Just to reiterate, the length stated by Siminoff is the scale length which is only peripherally involved with the actual length of the finished fret board.

BPorter - Posted - 01/19/2012:  12:53:22

I remember back in the later 1960's/early 1970s when StewMac offered a Gibson fingerboard as 26 3/16 inch scale length generated from the math. formula along with a few others and they were shorter than the pre-war Gibson fingerboard 5string lengths. I built my fret saw scales from actual pre-war fingerboard layouts which I believe were "tempered" and didn't equate to the math formula of which I can't recall right off the top of my head.

Anyway, they noted very well and as Ken stated were 26 3/8 inch length scale instead of 26 3/16 as many advocated back then.

Bill Porter

BPorter - Posted - 01/19/2012:  13:03:18

quote:

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Originally posted by BPorter

I remember back in the later 1960's/early 1970s when StewMac offered a Gibson fingerboard as 26 3/16 inch scale length generated from the math. formula along with a few others and they were shorter than the pre-war Gibson fingerboard 5string lengths. I built my fret saw scales from actual pre-war fingerboard layouts which I believe were "tempered" and didn't equate to the math formula of which I can't recall right off the top of my head.



Anyway, they noted very well and as Ken stated were 26 3/8 inch length scale instead of 26 3/16 as many advocated back then.



Bill Porter

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 The tempered scale did not calculate exactly to the standard 17.817 formula used or rule of 18.

rudy - Posted - 01/19/2012:  13:38:40

quote:

---

Originally posted by BPorter



I remember back in the later 1960's/early 1970s when StewMac offered a Gibson fingerboard as 26 3/16 inch scale length generated from the math. formula along with a few others and they were shorter than the pre-war Gibson fingerboard 5string lengths. I built my fret saw scales from actual pre-war fingerboard layouts which I believe were "tempered" and didn't equate to the math formula of which I can't recall right off the top of my head.



Anyway, they noted very well and as Ken stated were 26 3/8 inch length scale instead of 26 3/16 as many advocated back then.



Bill Porter

---

 It's widely known that there were several methods of generating fret positions in the past, all of them more or less based on equal temperament since early in the 19th century.  It is also obvious when the "early" period instruments are closely examined that manufacturers (including Gibson) often "fudged" the scales to improve intonation.  This may have been the result of using geometric projection for fret position (a common method) which would tend to have more error introduced as a result.  A lot of the real reasons will certainly never be known, but it's a pretty safe bet that equal temperament will be widely accepted as the standard for a LONG time, until our cultural tastes diverge or homogenize with other cultures to the point where it will no longer satisfy the western ear.

There ARE other cultures, even within the US that adhere to other temperaments, such as the Cajun musicians who tune their instruments, particularly diatonic accordions to just temperament.  There's a bit more about the reasons behind that in the linked web page below.

You may have seen my take on equal temperament as presented HERE.

uncle.fogey - Posted - 01/19/2012:  13:48:53

Bill,

I've been off line and catching up.

That's very interesting - you are an amazing source of information! I NEVER KNEW Gibson waded into the tempered / untempered scale waters - they were ahead of their time.

I use 17.817154  on a spreadsheet, generate a drawing with Adobe Illustrator, make a printout, paste it onto the fingerboard blank, and cut the slots directly on the drawing.  My fret saw has a kerf of 0.025, so all the crazy decimal places in 17.817154, are only for the long view - 1 - 22, to eliminate compounded error,  not for individual fret spacings - my saw kerf is greater than the last 4 decimal places.

I'd LOVE to know what Gibson did!!  Trying to compensate intonation with a fretted instrument has always been conceptual art.

OK, we can get a grin out of this one:  In this era of computers, you can calculate ANYTHING.

A Finnish guitar maker named Juha Ruokangas has calculated each fret on each string and determined what is necessary to achieve perfect intonation.  We owe him a debt of gratitude for showing us what it's REALLY about mathematically:

So, do we want to do this with banjos?  What happens if you change string gauge?

Much of the blame for this basic misunderstanding can be laid on reliance on digital tuners as opposed to your ear - can you actually picture Earl Scruggs, Ralph Stanley, Eric Weissberg, Don Reno, Dave Guard, Bela Fleck, Tony Trishka, etc etc with one of those things sticking out of their peghead?  It's like photographing the Mona Lisa with a cell phone and thinking that's the Mona Lisa.

BPorter - Posted - 01/19/2012:  15:14:02

Ken, if memory is still correct, I talked with George Hall about the Gibson banjo scale lengths and he referred to the rule of 18 and according to him, the scale was set up totally by ear for intonation; They had some type of moveable fret position and tested each fret location/position for whatever the scale length was set up for getting the intonation by ear. George gave a name out that did those scales but it is not in my memory bank as the persons that actually designed those beautiful banjo inlay patterns we love on those prewar "banjers"!

The banjo scale that I duplicated certainly was a little longer than the computer generated ones by as much as an 1/8 inch at least. I believe I got my hands on a slotted pre-war fingerboard that was never installed and cut a 1/2 inch wide strip from the middle of it to make a template for my slotting machine which cut only one slot at a time and not gang sawed like the factory production slotting machines.

I know I have bad days that nothing sounds in tune and will argue with a tuner in a minute....and then when it sounds right on, the tuner says otherwise, mostly flat 2nd string; that is with a regular bridge.

BPorter - Posted - 01/20/2012:  08:48:02

Scale length and bridge placement on the banjo has been covered in many, many threads here on the hangout. There certainly is a "sweet spot" (ideal placement) for the bridge say on a standard 11 inch diamter head and that is real subjective since we hear what we want to as far as the tone/sound we like.

The 27 inch scale certainly puts the bridge back toward the tailpiece and IMHO reduces some of the tubby, hollow, growling sound many are in love with.

Those RB75 banjos and others that have the 22nd fret with just enough fingerboard to hold the fret in place pushes the bridge back toward the tailpiece for the standard 26.375 Gibson pre-war scale length.

I know of at least one outstanding prewar RB75 that has a replacment 5 string neck made with a much longer distance between the 22nd fret to the tension hoop and there is not any difference in the sound before and after using the original neck that had the shortened fingerboard length at the 22nd fret. Again, this is open for each ones own opinion and if there is a difference to your ears then go with the fingerboard scale/length that suits you. I am not sure whether the replacement neck had the identical tempered fret spacing and the 26.375 inch scale length.

All the variables present in a banjo really makes it interesting and a challenge to try and ascertain what the effect that each component has on the total.

Bill Porter