So, following on from this thread -
https://www.thefretboard.co.uk/discussion/228868/my-sons-ngd-and-a-problem, yesterday was the day my son's new Jackson V got extra special attention from the luthier. All frets levelled and dressed and plays like a dream sans buzz. A big shout out to Danny at Leicestershire Luthier for the work - I can thoroughly recommend them!
However, there's a problem with the FR Special that has us all stumped;
Pull up and all strings return nearly a semitone sharp. Push down and they return to the correct pitch. This happens every time without fail - a pull up needs to be followed by a push down every time.
The trem plate blades and posts are in perfect condition and lubricated. Nut is solid and the clamps are tightened with no slippage/movement when pressure is applied behind the nut. Intonation adjustment screws are tightened correctly. Claw is also lubricated at the spring contact points. The trem is flat, and we also tested it with it completely level from E to E.
Also, the stud inserts are not level. The bass side is slightly high in the cavity, where the treble side is recessed relatively deep into the body. I guess that's standard to allow different degrees of adjustment to compensate for string diameter?
I have considered swapping the springs out to see if that helps, but it can't be them can it?
The prime suspect is the stud spacing which is approx 74.6mm centre-to-centre, rather than bang on 74mm. Could this be the source of the problem?
Comments
I have mine dive only , I’m guessing the extra stretch from pulling up might be made less trouble with a good stretch . I’m not very technical with this stuff to be honest but it’s an idea, good luck anyway , jackson are lovely guitars
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
I would suggest the lightest gauge for a trem would be 10s I use 11-49 on my suhr & Prs DGT and no problems but I don't
dive bomb or go mad on my trems.
Any half-decent Floyd, even cheaper ones, works perfectly well once adjusted properly and locked down - if it's consistently sticking anything like as much as a semi-tone out, something is catching where it shouldn't. It's *just* possible it's some sort of problem with the knife edges, but unlikely if it doesn't do it in the down direction. Likewise, if it doesn't do it on a down-bend it isn't going to be the nut slipping on its shelf.
Misaligned (by height) stud inserts are not ideal but shouldn't be the cause.
From experience I would guess that the block is just touching the cavity wall somewhere when pulled up beyond the rest position - sometimes it can be quite hard to see, it can be as little as a bit of routing burr sticking out.
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
It has 10s installed and I think I'd need to add additional springs to balance the trem in standard tuning with anything heavier?
Personally, I wouldn't use heavier than 10s unless you're tuning down, in which case three springs is still fine. Knife edge wear has been a noticeable problem on Floyds I've worked on with excessively heavy strings.
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
I would suspect the problem was at the nut, but you say you are sure that is solid.
I have the problem the opposite way, have to pull up to get the strings back in tune, and I think that was more related to wear on the posts.
My final suggestion would be to check the springs are absolutely and perfectly balanced, which is a bit trickier on 10's, and I find it can feel stiff with this gauge, maybe go down to 9's and see if you can set it up so that it flutters, or warbles, rather than just doing divebombs, usually this will be using 2 springs fairly stretched out.
At least this would maybe isolate the springs as the problem, it is a fine balancing act and if nut and posts are in good shape the only other thing that is changing under tension is the springs.
The only thing left that could be causing a problem are the springs themselves or the issue with the post spacing, in my opinion.
Sometimes you can't even see they're worn, although sometimes you can see a gold colour through the finish in the V where the bridge plate sits.
Usually it's caused by 30 years of diving but in most cases on new guitars its a post(s) which aren't correctly hardened or not even hardened at all. They wear very quickly by winding up and down under tension to achieve the desired action if they're not hard enough.
Get some proper Floyd Rose or Schaller ones, measure where the V is on your original posts (before removing) in relation to the rout or steel bush in the body with an accurate steel rule, then fit the new ones with the V at the same heights.
Touchstone Tonewoods usually have them in stock.
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein