Setting a bridge/saddle for both nylon and steel - Yamaha

[deleted]

I have an early 70s Yamaha S-50a, which is basically a laminated-top Yamaha Dynamic. These guitars were engineered to accommodate both nylon and steel strings. But the bridge saddle was uncompensated; with my guitar at least, there are massive intonation problems when I use steels (I use silk and steel strings).

I've just done a neck reset on mine and as the bridge was lifting a little I removed it too. Now I'm wondering whether I can alter the bridge so as to compensate the saddle, but it would be a shame to lose the nylon capacity also so I was wondering if I could manage to use both, altering the bridge so that different saddles can be inserted.

To give an idea of the intonation problems: prior to the reset the E string intonation was 25-30 cents sharp at the 12th fret.


I figure I'd have to alter the bass side of the saddle so the apex is 2mm further back.

The bridge has a triangle groove for the saddle. Any suggestions of how I might achieve this (ability to switch saddle for nylon or steel)?

[kiwigeo]

I'd say that guitar came from an era when Japanese guitars were about were Japanese cars were in the 1960's. I had a few Japanese made acoustics from that era and they were pretty average guitars.

Some quick research suggests that this guitar was produced as a steel string rather than a classical. The tuners certainly appear to be for steel strings. That said there also seems to have been varying "flavours" of these guitars...some had plastic rollers on the tuners which means only nylon strings could be run.

Is there a truss or reinforcing rod in the neck? If there is then I can see issues here when swapping between nylon and steel strings. This model in good condition also appears to be something of a collectors item and can command a fair price.

The bridge appears to be a classical bridge and I don't see any practical way to easily change out the saddle to allow for proper intonation with both steel and nylon strings.

The saddle slot......whoever designed that saddle slot must have had a few too many sakes the night before Ive found a few references to a rod shaped saddle that would have sat in the V shaped "slot".

[deleted]

I like Japanese cars from the 60s (Datsuns).

I've never seen any with plastic rollers, where did you find that?

Yes, the neck is reinforced -with a square 'tube' of what I believe is aluminium. The neck of mine is really straight; but cosmetically the guitar is in poor condition.

I don't know about the V groove. I've also read about 'tooth pick' like saddles. I've just cut a piece of bone, made the bottom triangular; sits in there without rocking. I think there may be some advantages to this, since pressure from the strings is (I think) applied down and toward the neck rather than simply down.

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I think there's room to fill the saddle groove and then re-cut along at an angle for compensation, though I've never done it before. Perhaps I should just use it for steel strings.

Good work on the research.

[simso]

If the intonation is that far out, then this particular one was made to be a classical nylon.

Remove the bridge put in a proper compensated bridge, and you will be fine, provided you do have some form of neck re-inforcement and provided the top is braced well enough to take the load and provided you are running tuners for steel strings



Steve

[deleted]

Perhaps these guitars originally ran special strings which didn't require compensation. I've heard about long lost Dynamic strings.

One thing which is odd though, is that by the time my guitar was made Yamaha had long been making the FG series with compensated bridges, so they knew how to do it properly, and at the same time they were also making the classical equivalent of mine, the G-50. So I wonder what niche my guitar was filling.

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What I thought I could do, is, I could cut a saddle slot, about 4mm thick and then put in a 4mm thick saddle and profile it for either steel or nylon. I'm sure that would work, I guess the question is whether having a saddle that thick would be bad for the tone or not.
What do you think?


Simso, if I install a compensated bridge then I'd need to drill string holes through the top. Not sure if my guitar is manufactured to take that (different) kind of load.

This is a picture of the bracing here, though on my guitar I can feel a panel of wood which sits beneath the bridge piece.

The top of mine has only slight belly bulge.

[kiwigeo]

Sweet FA bracing...guess Yamaha were putting all their faith in the laminated top. I'm curious as to why theyd make a two piece top if theyre using laminate.....they went to laminate on these guitars because they were having issues with solid tops splitting.

Re the bridge....if you don't intend keeping the instrument looking original then like Simso says I'd put on a better bridge and compensate the saddle.

Looking at the top of the bridge tie block it looks to me like someone has had nylon strings on the instrument at some stage

Datsuns......LOL, I recall having to back my gf's 120Y up a really steep street in Wellington NZ back in the 80's....the car wouldnt go up in first gear forwards.

[deleted]

That might even be a picture of a solid-top Yamaha. The guitar in that picture is much older than mine but the bracing is the same.

I was coming around to the idea of sticking a nice new through-body bridge on there but I've realised that unless I altered the angle that the D and G strings pull through the bridge I'd be drilling through the centre piece bracing which would be a huge no-no!~

I'm thinking about deepening and squaring the original groove saddle slot, filling it with wood and then cutting a new, compensated slot by hand. A bit of a hodge podge, but as I've said the guitar is in pretty poor condition already (graffiti scratched deep into the top) though a bit better than a 120Y, I think.

[kiwigeo]

A through body bridge wont work without a bridge plate for string ball ends to pull against.

Filling and then routing the saddle slot...this might work if you go for a thick saddle. The latter also works for you in that you have more room for profiling the top of the saddle to fine tune compensation.

If it was me I'd whack on a whole new bridge...the old one just looks clunky and ugly.

[Mark McLean]

You could make a new pinless bridge for steel strings (like, lowden, breedlove, ovation)

[Nick]

May look bulky, but you could cut that 'saddle groove' deeper (as you've already suggested) and make a stepped saddle that is 5mm wide on it's top and then stepped down to locate into the newly routed slot (whatever width you ended up making it) then just file ramps on the saddle to locate the strings break point at the compensated distance. A 5mm wide saddle should accommodate the required 1/8th compensation. This all depends on the current slot position being somewhere in the ball park of course.
This way you could always make a plain second saddle the same width as the newly routed slot and then guitar could always be swapped between Nylon or Steel strings as the mood takes you.

[deleted]

Aah, That's what they're called, pinless bridges. Thanks, I was trying to find something like that.

Nick, by stepped down saddle do you mean that, for example, at the bottom the saddle could be 3mm while at the top it could be 5mm?

Is there some well-established reason for not having a thick (5mm) contact point?
I suppose it would make the pressure exerted lower and could therefore lose tone/resonance. But is that the reason?

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I've just cut the slot deeper and filled it with rosewood. Tomorrow I can decide whether to cut an angle slot or straight. I feel like giving up on the nylon though.

[Nick]

Nick, by stepped down saddle do you mean that, for example, at the bottom the saddle could be 3mm while at the top it could be 5mm?

Yes thats what I was meaning, so the bottom is smaller to fit in the slot and the top is full width. With a definite shoulder between the two so that the shoulder sits down against the bridge.

Is there some well-established reason for not having a thick (5mm) contact point?
I suppose it would make the pressure exerted lower and could therefore lose tone/resonance. But is that the reason?

I make all the saddles on my guitars 5mm wide, in this particular case you are governed on width by the amount of bridge material ( strength)you have left after slotting but a new bridge I can cut a 5mm wide slot and still have plenty of meat left at the front to avoid breakout. There is no technical reason for a saddle to be specifically 3mm wide apart from tradition. As long as the string has a definite break point at it's front edge where it leaves the saddle so it doesn't buzz, thats all that matters. I then radius from the break point back instead of ramping, this way you get a good contact area on the string as the string rolls down towards it's anchor point. This doesn't alter the tone/ resonance and doesn't alter the pressure the string exerts on the saddle, infact to my way of thinking, I think it may enhance tone slightly if anything, as more of the saddle is absorbing any residual energy left in the string after the break point. I don't know if he still does but Ervin Somogyi used this method (it's where I got the idea to use it from) and i never heard any owners of his guitars complaining about reduced tone. It may enhance or it may not I've never carried out any definitive A-B tests to prove it, but either way it doesn't take anything away from the sound.

[deleted]

I've got what you mean Nick. That's a good idea to ensure there is enough strength left in the bridge.

I decided to just cut a compensated angle for steels. Clamped and glued now.

Wasn't able to check intonation first. Guess I'll find out soon enough.

[deleted]

Took forever to set this up. I ended up angling for a steel compensated slot.

The E slot on the nut was worn plus the 11th fret had lifted slightly high, both causing intonation issues which added to the confusion of setting the saddle.

I used a 3 and a bit mm saddle, which still needs some compensation for the B string. I would probably be better off using a thicker saddle but didn't have one at the time.

Don't know what classical strings will be like with this set up - might check that out later.

Here it is:


You can see the scratches in the top. Any idea how I might reduce these?