Issues like this are the entire reason why in
every post about Floyd swaps I´ve ever commented on I
explicitly mention the difference in mounting distance between a Schaller Floyd and everything else. Unfortunately, those that remained during my prolonged absence apparently weren´t reading, or most of the posts in this thread would not be suggesting semi-solutions and pseudo-workarounds with at best questionable chances of success and at worst guaranteed expensive failure.
The fact of the matter is that you´re missing a whole 1/16" of intonation length from the posts being exactly that much farther forward than they would be for an OFR /FR Pro, and as a result that 1/16" is missing from the knife edge-intonation point distance.
It´s almost always either the G or Low E string that bottoms out before being properly intonated.
There are exactly 2 correct solutions here.
1. Put the Schaller back in with a new baseplate for about 50$ from Allparts, LMI or Stew-Mac (or if necessary I can send you one in your choice of color that left the factory less than 24 hours before I got it, for cost + shipping of course), which will also have the brass inserts that have been standard since 1992 specifically to alleviate the stripping issues. Alternatively, in case you chucked the old one in the trash completely, Jackson /Charvel nomenclature for the trem assembly is JT-590 should you require a compeltely new unit, this has the advantage that the proper bridge radius will be pre-set, as opposed to you having to shim the saddles as would be the case on a"generic" Schaller Floyd from any other supplier. Of course Allparts, Stew-Mac and others will happily provide you with a new, non-branded Trem as well.
2. Dowel the holes and redrill them 1/16" further back. Assuming of course that you have enough meat left on the mounting ledge, which you probably won´t as the trem is recessed on a Spectrum. Should it work after all, you will probably have to extend the rout for the wings, because the baseplate will otherwise bottom out on the back lip of the cavity.
The nut is not the problem, the setup is not the problem, the ftrets are not the problem, the trem swap is very specifically the entire problem.
Therefore, Kramersteen´s recommendation to replace it with an OFR is, with all due respect, expensive bupkus, because you will habe the exact same problem. You can put in ANYTHING that is not a Schaller Trem in there, and the problem will not go away.
I will bet you free setups FOR LIFE (yours and /or mine) that you will still have the exact same problem with anything but a Schaller Floyd, unless the trem has a slightly different baseplate geometry (only one that comes to mind off the top of my head is the Graphtech Ghost...) that might just barely give you half a millimeter of extra travel and your pot of 4 leaf rabbit´s feet makes that just barely be enough to intonate.
If you don´t believe me that this is the entire problem, grab a ruler and measure for yourself. An OFR /FR pro / IBZ Edge /Gotoh /Takeuchi Floyd and similiar as well as thir knockoffs require the line between the center of the posts to be exactly 25" from the nut to intonate properly, measured along the guitar´s centerline, of course. A Schaller and only a Schaller (or copy of one ) requires 24 15/16" due to it´s slightly longer baseplate geometry. This is the same difference in geometry that makes a Schaller feel different from an OFR.
While on the topic of the nut, if you install the locking pads properly they work more effectively. Yours are turned 90°, resulting in the strings being locked at only one point across their length instead of being clamped down for the entire width of the nut. This is why the pads have a curve to the bottom when viewed from the side, and are straight when viewed from the front or back.
If your tech didn´t catch this most basic of issues, IMO he shouldn´t be working on Floyds, and probably not on guitars at all. Simply because all of this is laid out very clearly in the Guitar Player Repair Guide by Dan Erlewine, aka. "The Guitar Tech`s Bible" (there´s even a table with exact mounting distances for most popular Floyds in the Floyd Rose installation and setup chapter, OFR and Schaller FR units are explicitly included in that table), as well as numerous other works by Melvin Hiscock and other well known luthiers. These are books that anyone wanting to work on guitars in a professional capacity should ideally be able to recite cover to cover in their sleep.
Not to mention that a level and crown is most certainly NOT the proper solution to a single string not intonating. EVER. In fact, it´s almost never the solution to ANY intonation issue (there are exceptions, but they are few and far between, and usually involve significant environmental damage). But it IS a great way to earn more than you should be by selling the customer work he doesn´t need. I´m sorry he ripped you off. If I were you I´d find a new tech ASAP, ideally an honest one that actually knows what he´s doing.
Adding compensation to the nut MIGHT help you, but without the proper amount of travel available it is actually likely to cause even more problems, because you´re shortening the scale length on that one string without correspondingly repositioning the frets, which will affect your temeperament and overall in-tune-ness. Again. it MIGHT work, just like your ears also might be screaming for mercy every time you use the G string afterwards becasue they don´t like the new temperament.
But why someone would choose a halfassed crutch of a solution with a questionable outcome when you can do it right and be guaranteed that the problem is gone is entirely beyond me.
There is, however, a third potential workaround, and it is by far the cheapest of all: A
wound G string. This will usually move the intonation point up to a spot in front of the B string. Not guaranteed to work, but definitely cheaper to try than wrecking and replacing the nut in a failed experiment or purchasing an entirely superfluous new vibrato unit.
