There is no formula for when to change up a set of banjo strings. I find that at a certain point – and the amount of time doesn’t seem to be consistent – my strings seem to lose a bit of their brightness, and as well, I find it more difficult to get them tuned precisely, and I notice they seem to not be able to hold their tune as long. This is not scientific. I just notice the sound, the brightness, the resonance of the strings has changed. I usually check the tightness of the head, as if that loosens up a tad, it changes the resonance of the strings. If the head is adjusted correctly, then it must be time to change strings.
Then when I put a new set on, the strings usually seem to be super-bright for a while, maybe even a touch too bright, before settling in to “just right”. I was talking to my brother the trout today – Salvelinas Fontinalis. He doesn’t change his strings nearly as often as I do and he doesn’t notice much deterioration of the sound or any issues with tuning. How curious we would have different observations and experiences.
I’ve tried some different brands of strings, and for the most part I can’t decide if I like one brand better than another. One brand was cryogenically frozen, whatever that means. I even go back and forth as to my preference for a bronze 4th or a stainless steel forth string. I suppose there are only a couple places that actually make the wire used in strings. Maybe the brand really doesn’t make a lot of difference. This evening, I tried a brand of string I had never used before – Sit. For the first time I noticed a decided difference in the the strings. They don’t seem to have that “over-brightness” I described above. The gauge of my 4th string is just a wee bit bigger than I usually use, and this is giving that string a bit deeper bass response. It will be interesting to experience how they sound after a few days.