Spec'ing a Nylon String Crossover

[Spook410]

So I'm putting together spec's for a nylon string crossover style guitar. Not something I know much of anything about. By crossover I mean nylon strings, narrower nut, a bit of radius to the fret board, cutaway, and maybe other departures from classical, and flamenco guitars. Mainly the goal here is the occasional bossa nova and recording. Probably not a primary instrument.

So.. what bad would happen if I kept the nut width close to 1 3/4"? In a steel string that's where I don't want it any wider. Yet many crossovers are quite a bit wider emulating their classical and flamenco cousins. Do you really need all that width if there is no intention to include the techniques and repertoire associated with classical music? Is there something about nylon strings that call for more width? Was thinking 44mm. Might be able to stand 45mm.

Same with neck radius. I see a 30 inch radius on some crossovers. Is this amount degree of flatness really required when bad habits like wrapping thumbs and less than ideal wrist position are going to be the norm?

Scale length.. probably 647mm (25.5") though I could spec 25". Typical body of 15"X3.75" seems about right. As for tone woods, spruce top (cedar or redwood may not be an option) is fine but what about back and sides? EIR, mahogany, and maple all have their strengths. Leaning towards EIR.

And finally, sourcing a good guitar. I've tried some of the affordable crossovers and really didn't like them much. So.. maybe Mr. Wu. Don't believe it's something he normally builds. Not sure he will build it but he seems to often be up for an adventure. Though I don't know how his lattice brace skill set is doing. Still, should be better than the mass produced stuff while maybe not be as good as the boutique guitars. Speaking of which, here is a picture of a nice boutique guitar from one of my favorite builders, Goodall. Sigh. If money were no object.. but it is. So more an example of a nice looking guitar that conveys my idea of what a crossover looks like.

[Stringswinger]

Spook,

Before my pal Rick Turner passed away, he and I talked about having him build me a nylon string crossover. We were going to use ES-175 specs, since that is what I mostly play. That is 24.75 scale, 12 inch radius and 1 11/16 nut. Rick told me those specs would not be a problem and he was the master luthier. Max405 of this forum seemed to think that with the nut being that narrow, the thick treble strings of a nylon string guitar might be an issue. I never commissioned the guitar and Rick died, so that idea is now gone. If I was going to do one, I think I might go with a 1 3/4 nut just to be on the safe side. My Thames classical is short scale (630 mm) and plays great. And all crossovers have some radius, I would seek a few opinions about what might be ideal.

The problem with any commissioned guitar is that you never know if you will like it until it is done and in your hands. Good luck!

[Woody Sound]

There a a lot of 1-7/8" crossover nylons available in stores to try out. Try one to see if it is still too wide. Myself, I would love to see a 1-3/4 nylon crossover.

[mr. beaumont]

As someone who has recently been playing a crossover with a 1 7/8" nut, 1 3/4" sounds too close for comfort.

[Jimmy Mack]

Not to criticize, but you are specing a lot for a guitar that won't be used all that much. You may not be happy with a narrow nut and fat nylon strings. Scale and radius are, in my mind, less of an issue. Why does it have to be a spruce top with certain woods for sides and back, again for occasional use, other than aesthetics?

By compromising the tradition of a classical guitar build, you might just miss out on the beauty of the "real" thing.

In my experience, once I played and owned trad. classical guitars, I fell in love with them, and always kept one. Now I have 2. In fact, I now play and study classical guitar, the "steels" sit on the side.

But that's me. My suggestion to you is to go and play a few of your choice, and go with the one that works for your fingers and ears. (I love cedar tops more than spruce - they seem more alive despite what the reviewers and ads say).

I have a cheap "student" guitar I bought at a flea market, that is incredible for what it is. Brazilian made, cedar top, laminated rosewood back and sides. It sounds a good as some recordings I have heard. I would not hesitate to play it anywhere.

I will end by saying that, with my inexpensive classical, and with the more professional model I now enjoy, I find that the greatest differences arise with the choice of strings I install. Many good ones to choose from, and I don't buy the most expensive ones. It's more a matter of finding the best string (and string material) for each guitar. In stores, the strings on the demo models can be awful.

So best of luck, and enjoy the hunt.

[Woody Sound]

As someone who has recently been playing a crossover with a 1 7/8" nut, 1 3/4" sounds too close for comfort.

I have a 1-7/8" crossover, and a Godin nylon slim, which is closer to a normal archtop. FOR ME, the 1-7/8" is just a little bit too wide for quick jazz chord changes and picking runs (if using a pick). And when using a pick, the string spacing at the bridge is a bit too wide. On the narrow Godin, the bridge spacing is narrower for picking runs, but the narrow neck is a bit cramped. My thinking is that 1-3/4" would be a happy medium. This is just me. Plenty of great players use wider necks for jazz. And FWIW, I am a classical/flamenco player using standard wide classical guitars. But when I play jazz/latin it's a different technique for me. Some internet vids of the G Slim. In the last one, he has the treble turned way down closer to an archtop tone.

[Spook410]

Not to criticize, but you are specing a lot for a guitar that won't be used all that much. <snip>

When ordering a Wu guitar, these are things that must be specified for the build. It's nice that there is so much first hand experience here to leverage in an area where I have little experience past the local Guitar Center. So I very much appreciate your comments.

As for top material, I know he has access to spruce. Not so sure about his redwood or cedar supply. But spruce is fine.

[Doctor Jeff]

I had an Alvarez hybrid nylon string guitar once upon a time that was great for jazz voicings and chord-melody, but lousy for any classical repertoire, which has a lot of arpeggios and requires reasonable string spacing.

So I got an Alvarez Artist series classical (A/E), which works for me. It has a flat radius and fairly wide string spacing, but with some practice it is very comfortable for playing all styles from classical to jazz.

IF all you want to play is pure jazz, though, the narrower nut guitar might work fine.

[rpjazzguitar]

If you can find one to try, the Yamaha AEX500N is a 24.75 scale nylon guitar with a very thin neck. Might help figure out what the limits are.

[coolvinny]

I have small hands and I just started playing a 7-string nylon with a pretty flat fingerboard, 25.5" scale and 2 1/4" nut width. I'm finding it's very comfortable to play BUT in general I'm strict about keeping my thumb central behind the neck. I do NOT do the classical guitar thing of putting the guitar on my left leg...either it's on my right leg like normal or on a strap. So I would stay away from 1.75" for sure. I think 1 7/8" would be the minimum.

[Woody Sound]

So I would stay away from 1.75" for sure. I think 1 7/8" would be the minimum.

I think the OP has to try things for himself before committing. As I previously posted, I have 2" on my classical and flamenco, but for jazz/latin stuff, I prefer the narrower neck. Different technique. But that's just me. YMMV.

[RJVB]

My resonator has a 1.75" nut cut with what turns out to be almost exactly the same string spacing as my Cordoba crossover has, with its 48mm nut width. String spacing at the saddle is a lot less than on the Cordoba (which has about a standard CG saddle) so that changes things considerably, but the resonator is a challenge for the left hand. The obstacle is not so much the string gauge but their tension and thus vibration amplitude which can and will cause them to buzz against or simply be muted by my fretting fingers. Impossible to put 3 fingers at the same fret on adjacent strings, for instance (I can just do that with the 48mm nut).
Another challenge: not pulling or pushing the outer strings off the fretboard.

So yeah, 48mm nut, but maybe a string spacing at the saddle that's common on fingerstyle steelies. How much narrower than on a steel-string would depend on how thick your fingers are, and how precise your left hand technique (as a violinist I was trained to use a *much* narrower neck...)

FWIW, this sort of thing can be tested by putting e.g. a set of d'Addario Folk strings on any acoustic (but careful that the 1st string doesn't get pinched in and snaps at the nut slot).

[Alter]

As mentioned, a narrower nut works great for anything with a lot of chords, jazz, brazilian. I have a Guild Paloma that i ordered from the Guild custom shop years back, and i had it made with a narrower nut, close to my acoustics, cause i use it for groups, jazz material, etc. But for actual classical pieces and technique though, i would choose a classical nut width.

[RJVB]

Supposing you never use thumb-over techniques you could get a wide-ish neck (say 48-50mm) with a >= 16" radius and set up the nut and saddle string spacing to your convenience (the latter would require a slotted saddle and/or a hole-less tie block with some kind of texture to keep the strings from sliding). If you keep the high E at the same distance from the edge the presence of extra fingerboard beyond the low E shouldn't matter much, I'd think.

[Woody Sound]

My resonator has a 1.75" nut cut with what turns out to be almost exactly the same string spacing as my Cordoba crossover has, with its 48mm nut width.

I believe the Cordoba crossovers have a 1-7/8 width. 1.75" is around 44mm.

[RJVB]

My Cordoba has a 48mm nut - I'm too lazy to convert that to the units of a fractioned imperium
48mm is a very standard size for nuts on nylon crossover guitars, and it actually allows playing a lot of classical repertoire without too much problems. I understand it was a relatively common width on 19th century instruments too.

It's the resonator from my that has a 1.75" nut width, and that's a value I know to correspond to about 44mm.

BTW, don't take this as a "get one too" endorsement ... of either guitar (no matter I do love my reso)

[Woody Sound]

My Cordoba has a 48mm nut - I'm too lazy to convert that to the units of a fractioned imperium
48mm is a very standard size for nuts on nylon crossover guitars, and it actually allows playing a lot of classical repertoire without too much problems. I understand it was a relatively common width on 19th century instruments too.

You're confusing me RJ. You wrote that the resonator (1.75" ~ 44mm) is the same as your Cordoba 1-7/8" ~48mm. There's quite a difference between the two.

[RJVB]

You're confusing me RJ. You wrote that the resonator (1.75" ~ 44mm) is the same as your Cordoba 1-7/8" ~48mm.

Not my fault, maybe you need new glasses?

My resonator has a 1.75" nut cut with what turns out to be almost exactly the same string spacing as my Cordoba crossover has, with its 48mm nut width.

The string spacing at the nut is close to identical on both guitars meaning that on the reso the strings sit very close to the edge while the Cordoba has a healthy margin.

[Woody Sound]

Not my fault, maybe you need new glasses?

My resonator has a 1.75" nut cut with what turns out to be almost exactly the same string spacing as my Cordoba crossover has, with its 48mm nut width.

The string spacing at the nut is close to identical on both guitars meaning that on the reso the strings sit very close to the edge while the Cordoba has a healthy margin.

With respect, that's just wrong. 1.75" is roughly 44mm, 1-7/8" is roughly 48mm.


inches to mm - Google Search

[RJVB]

With respect, that's just wrong. 1.75" is roughly 44mm, 1-7/8" is roughly 48mm.

That's the problem with fractional imperial values: you lose feeling for scales, differences etc. We are talking about 4 mm difference, 2mm on either side of the E strings.
I was going to give you some more calculations to ponder, but this is simpler:
E-E spread (centre to centre) at the nut:
- Gretsch Alligator: 39mm
- Cordoba Fusion: 39.5mm

[Spook410]

I think the OP has to try things for himself before committing. As I previously posted, I have 2" on my classical and flamenco, but for jazz/latin stuff, I prefer the narrower neck. Different technique. But that's just me. YMMV.

You make a good point Woody. And even in a small Guitar Center will have a few things to try.

[Woody Sound]

Cordoba Neck Styles - Cordoba Guitars

[Alder Statesman]

H

Cordoba Neck Styles - Cordoba Guitars

The Cordoba Stage has a neck closer to the Fusion. Comfortable 12” radius fingerboard. The neck I would describe as “thin D” despite the specs reading thin C. The nut is 48mm.