Zero fret/nut problem on a Yammy SG-2: advice?

[HorseyBoy]

So I love the Yammy SG-2 I picked up in Japan. Here it is:



Possibly the coolest-looking guitar I've ever seen. Sounds great and feels great, too. But I've started to become a little hesitant about playing it because there's a problem with the zero fret that's almost impossible to ignore. When I first got it the G and B strings would 'ping' a little when I'd bend them at what I assumed was the nut but was actually the zero fret. Like all frets with a bit of use on them, the zero fret had developed little grooves and the pinging noise would happen when the strings slipped out of and back into the grooves.
But the grooves weren't deep and I figured I'd be able to polish them out with a little 0000 steel wool, which I did. So now the strings don't ping in the grooves of the zero fret.
The problem is, now they ping like crazy moving back and forth in the nut slots - every string bar the bottom E. If I throw a capo on the first fret (or anywhere else) everything is wonderful and the guitar plays like a dream. But as soon as I pull the capo off the pinging starts up and sounds like a badly-tuned piano (Lee Ranaldo and Thurston Moore would love it).
Here's a close-up of the zero fret and nut.



So what can I do about it? Obviously the nut slots are way too wide for the strings I'm using (10-46), but the nut is chrome-plated brass and, because it's an original part, I don't really want to mess with it. There's not much of a break angle from the nut to the tuning pegs either, so there's not really any tension to hold the strings in place. I'm not really sure if heavier strings would help much (seems like there'd still be a lot of room for them to slip around) or whether or not I could solve the problem by putting in a new zero fret.
Any ideas on a solution? I'm wondering if I should just have a new nut made. I could always throw the old one back on if I ever needed to.

[selectomatic]

I have an SG-3, but haven't experienced the kind of problem you mention. There's some detectable wear on the zero fret, but I couldn't say it has actual grooves. However, it's strung with flatwounds and I don't bend much. Sounds like your SG-2 was fine until it had some wear; maybe a stainless steel zero fret would be more durable and at least delay the onset of grooves?

For sure, there's going to be slop in the nut slots even if you step up your string gauge. I'm using 11s, and the four lowest strings can be moved laterally in the slots. But, as I said, the 'groove & ping' thing hasn't been a problem, so perhaps different strings are worth a try before messing with the zero fret or nut. I wouldn't recommend 12s on these guitars, BTW. Wish I could be more helpful -- some of the more knowledgeable, guitar-building members can probably offer more specific insights.

[HorseyBoy]

Thanks for the reply, selectomatic - really nice to hear from someone with the same (almost) guitar. I do have a set of flatwounds I can try so I might give those a go, although I prefer all my guitars to use the same gauge.
But I'm starting to think it's not the width of the nut slots but the HEIGHT that's the problem - they might need to be lowered. This post on the Mandolin Cafe seems to be on the mark:

The zero fret needs to be the same size and height as the other frets. There is NO need for any extra height; it is but another fret, no more, no less. It's really -that- simple. The zero fret is the same size and height as the others, and the nut slots are cut deeper, down to the board, to provide the break angle, and of course, the string spacing. In a regular nut setup, the ideal slot depth is exactly the same as the fret height. An example: place your finger across all four pairs(barre chord style), at the first fret; that fret is the same size and height and the second fret, but by barring it, you've now made your finger the nut, and the first fret the zero fret. Didn't need any extra height, right? right. Barre the strings at any fret, and it's still the same. It's -that- simple; the zero fret uses low nut slots to provide the break angle, which replaces your finger to barre the strings tight onto the zero fret.

A lot of misinformation, and misunderstanding out there on this subject, I see, but it doesn't have to be so; it really is as simple as I describe above.

[selectomatic]

You may be onto something with the slot height. Checking my SG-3, I see the slots are indeed "down to the board," as the excerpt says.

[HorseyBoy]

^ Yeah, on close inspection the slots on mine are the same. But with the exception of the bottom E, the strings aren't sitting on the bottom of the nut slots - they're kind of floating free. Seems like there's not enough of a break angle over the nut down to the tuning pegs. That might be because my zero fret is too low, or it might be that the strings don't have enough tension (because they're too light). If I could lower the string tree (which holds the G, B and top E) a tiny bit, that could be enough to sort those strings out. With the A and D strings I'd just have to make sure I get maximum winds on the pegs.
But I think I'll hand it over to a luthier for a look.

[selectomatic]

... with the exception of the bottom E, the strings aren't sitting on the bottom of the nut slots - they're kind of floating free.

I'd never noticed before, but that's exactly the case with mine, and yet I haven't been getting the grooving problem. The luthier sounds like a good plan. Good luck, man. Let us know when you get it sorted out!

[HorseyBoy]

^ Will do! And thanks again for your help.

[HorseyBoy]

Quick update for selectomatic. Got the guitar back from the luthier last night and will try to give it a run today. First impressions are good though.
Here's what he did. First, the neck was dead straight so he gave it a bit of relief. He also adjusted the saddle heights at the bridge for the 7.25" radius (again, the saddles were pretty flat overall) - just a good, basic setup, which will certainly help overall and also improve the break angle over the nut. He also gave me a new zero fret. He then discovered that the string tree is actually two pieces, the shaft and the head of the tree, and found a new shaft, about 1.5mm shorter. Throwing that on also helps the break angle at the nut on the treble strings (and it meant he didn't have to alter the original part).
The one thing he did which I wasn't expecting was to go DOWN in string gauge. I usually run 10-46 strings on all my electrics but he said he just couldn't intonate the guitar properly with 10s (the bridge really should be a good couple of millimetres further back but there's no way we're moving it) so he went with a set of 9-42s, which intonate pretty much perfectly. Told me if I hated it he'd happily redo it with 10s free of charge and would do the best he could with the intonation. So I'm gonna give it a week or two and see how it goes.
If the 9s weird me out too much I'm wondering if I could shim the neck a little at the end of the pocket to give it a little more length and allow it to intonate with higher gauge strings…

[selectomatic]

That's interesting. I hope this solves the problem. Regarding intonation, have you noticed any 'longitudinal instability' in the bridge? I've been experimenting a lot to get a buzz-free low action on my SG-3, and I noticed that when the bridge is raised past a certain point, it tilts forward (much as you've probably experienced with Jag/Jazz bridges) in the direction of the neck. I'm thinking this could well throw off your intonation by the 2mm you mentioned. You'll see this easily if you look at the guitar edge-on. My guitar intonates anyway, but at one point I had leveled the bridge by putting a shim under the front edge, just behind the end of the pickguard.

[HorseyBoy]

^ Hmmm, my bridge appears to be perfectly level, and I've never noticed a problem with it before.
Had a good play of the SG-2 running through a good amp and it's playing really well. Action is good - no buzz anywhere - and it's very nice to play. I'm still a little weirded out by the lightness of the strings but will stick with it for the time being.

[selectomatic]

Cool. I hope this means she's all fixed. Beautiful guitar, by the way!

[HorseyBoy]

Little update on this: I bit the bullet and had my luthier put on a new nut. It's bone but I can throw the original back on if I need to. The slots on the old nut were just too wide. The new nut is cut for 10-46 strings and works exactly as I hoped it would - no slips, no pings, no pops. Playing really well and looks okay, too. Nobody but a Yammy aficionado would even notice the difference, I reckon:



One day I'll get her re-fretted to complete the job but for now I couldn't be happier.

[slavemaster]

What would happen if you take out the zero fret?

[otis]

What would happen if you take out the zero fret?

Than every fret would sound out of tune, I guess.
The longer distance to the nut(behind the usual placement) would create a longer string length than the frets are positioned for.
It would be something comparable as switching necks between long en short-scales.

[slavemaster]

What would happen if you take out the zero fret?

Than every fret would sound out of tune, I guess.
The longer distance to the nut(behind the usual placement) would create a longer string length than the frets are positioned for.
It would be something comparable as switching necks between long en short-scales.

Thanks for the answer.