#1
A while back I purchased a '91/92 Fender Prodigy body. I started a thread (here) asking for advice on a new neck. The original neck was 22 frets, and the new one has the following specs (it is a genuine Fender MIM):


- Fingerboard: Maple 9.5" Radius/241 mm
- No. of Frets: 21 MEDIUM JUMBO
- Scale Length: 25.5" (648 mm)
- Width @ Nut: 1.650" (42 mm)


The scale and other properties of the new neck match the missing one; the only difference I know of is the fret count.

I should have known something was going to go wrong when I got it... the predrilled holes didn't quite line up. They were very slightly off (I can't remember whether it was "too short" or "too long"). I had the holes filled, redrilled new ones, and had the neck attached. It looks great.

The problem is, I can't get it to intonate exactly. It's very, very close (especially on the lower strings). I have the screws on all the saddles torqued as far as they'll go... it looks very unnatural with them all completely flush against the back of the bridge.

The guitar plays great... but obviously the notes are slightly off on the much higher frets because I can't adjust the saddles any further.

Does it sound like I just need a full 22 fret neck for this thing?
#3
Is the distance between the nut and the bridge still 25.5"? (check and measure it on your guitar)

Check the scale lengths of both necks new and old (measure the nut, on the fretboard edge, to the 12th fret and double it for scale length)

If the scale length is correct, it should intonate, regardless of number of frets.




Quote by dogismycopilot
Absent Mind, words cant express how much i love you. Id bone you, oh yea.

Quote by lumberjack
Absent Mind is, as usual, completely correct.

Quote by littlemurph7976
Id like to make my love for Neil public knowledge as he is a beautiful man
#4
Quote by ohspyro89

No, it sounds like you need a different scale length. The amount of frets has nothing to do with it, and if you're all the way back on the saddles, it sounds like you need a shorter scale neck. But I might be backwards.


Quote by Absent Mind

Is the distance between the nut and the bridge still 25.5"? (check and measure it on your guitar)

Check the scale lengths of both necks new and old (measure the nut, on the fretboard edge, to the 12th fret and double it for scale length)

If the scale length is correct, it should intonate, regardless of number of frets.


Thanks for the quick replies. It's very much appreciated.

The problem is: I don't have the original neck to compare against. The guy sold it to someone else separately (it's described here).

How can I figure out the proper scale length without the original neck? Based on what you guys are saying it seems pretty likely it's wrong, but I am not sure how to figure out what's right.
#6
Well check the scale length on the neck you have now by measuring the distance between the nut (on the fretboard edge) to the 12th fret and double it.

Now measure from the nut to the saddles on the bridge where the string breaks over it, on the guitar the neck is installed on.

These two numbers should match.




Quote by dogismycopilot
Absent Mind, words cant express how much i love you. Id bone you, oh yea.

Quote by lumberjack
Absent Mind is, as usual, completely correct.

Quote by littlemurph7976
Id like to make my love for Neil public knowledge as he is a beautiful man
#7
I have a sneaking suspicion that the neck pocket on the body doesn't match the new neck; if the neck pocket is too deep then you effectively won't be using a 25.5" scale which the frets are placed for. How you'd fix it I don't know but it's a possible problem.
R.I.P. My Signature. Lost to us in the great Signature Massacre of 2014.

Quote by Master Foo
“A man who mistakes secrets for knowledge is like a man who, seeking light, hugs a candle so closely that he smothers it and burns his hand.”


Album.
Legion.
#8
Sounds like that fret is an issue. If the original neck was 25.5 and 22 frets with no fretboard overhang then it will be slightly longer than a 21 fret neck with the same scale. So now the nut is that extra fret closer to the bridge. Where its not an issue is on necks where a longer fret board is installed and the extra frets hang over the heel of the neck.
#9
Quote by Tackleberry
Sounds like that fret is an issue. If the original neck was 25.5 and 22 frets with no fretboard overhang then it will be slightly longer than a 21 fret neck with the same scale. So now the nut is that extra fret closer to the bridge. Where its not an issue is on necks where a longer fret board is installed and the extra frets hang over the heel of the neck.


This is actually what I suspected in the beginning, but couldn't tell for sure from the pictures of the old neck. It is my belief that the original neck was 22 frets with NO overhang, which I thought could account for the slight hole mismatch. But I thought that if the scales were the same it wouldn't matter.

I should have mentioned that suspicion up front. Does this change anyone's theories?
#11
Yea you can use some sort of shim between the heel and the and the little strip of wood where the pickup is. Dont know what kind of stability it will have. Small thin flexable strips of wood stacked would probably do the trick. You might have to deal with the saddles being jammed up a bit close to the end of the bridge so you dont have to use a bunch of shims. The holes being off isnt a give away. Ive seen knock off strats with misaligned holes but same scale and # of frets. Even on fenders they can vary.
#12
I'm not comfortable enough with my skills to redrill the holes for experimentation. I had a local guy do the work in the first place. Any ideas how I might do some more non-invasive investigation, so to speak?

I'll check the current scale measurements when I get home.

Also, if it turns out that the physical length is the issue, I'd be more inclined to just wait for a 22 fret replacement to appear on eBay, but I haven't noticed one in many weeks of watching (although I may be inept at watching ).
#13
Okay, I did some measurements on the Prodigy and some other guitars: an Ibanez Talman TC 420 and an Aria Pro II TS-500. Both are 22 frets.

Nut to middle of 12th fret:
Aria: 12 3/8"
Talman: 12 3/8"
Prodigy: 12 3/8"

(implies the same scale?)

Nut to edge of bridge:
Aria: 26 1/2"
Talman: 26 1/2"
Prodigy: 26 5/16" (3/16" difference)

(extra fret on the other two accounts for the difference)

Nut to end of neck:
Aria: 18 11/16"
Talman: 18 10/16"
Prodigy: 18 6/16" or 7/16" (near 1/4" difference)

So if the Prodigy neck were the slightly longer due to a 22nd fret, it would have about the same measurements as the other two similar guitars. The strings would be stretched out slightly further, alleviating my need to totally dial out the saddles screws, and it would allow me to intonate it... seems to make sense. Am I missing anything?

All this trouble for such a small measurement!
#14
Doesnt take much. The difference from a gibson 24.75 and a fender 25.5 is only 3/4 of an inch but hold the 2 necks fretboard to fretboard and see how big a difference it makes. I put a 24.75 scale neck on a strat body and its overall length is 1 1/2 shorter than my other fender with the regular scale. Feels like playing one of those kids guitars compared to my LP.