I had an sg standard years ago, an early 70's model. Sold it in the eighties to a kid across the street who was obsessed with AC/DC, wish I still had it ! It did not stay in tune as well as other guitars I've had, I think it may be at least partly due to its design; the long thin mahogany neck which is fairly unique to the SG. They seem to have that reputation. New tuners may help, but I have had some guitars with cheap tuners that stayed in tune very well. Put some graphite in the nut grooves, stretch your strings after you put them on, you might need to experiment with how you tune it; like always come UP to the proper pitch. Also make sure that you are not inadvertently putting a little pressure on the neck in relation to the body as you play it, like what mixmkr is referring to. Also, does it have the string gauge on it that you are used to? Lighter strings will tend be pulled or pushed slightly out of tune by fingers that are used to a heavier gauge. Try looking on the net for EXPERT advice (sites like Stewart-McDonald) on alleviating this problem with Gibson style guitars. Cool guitar, though- congrats!
