Ive had my tenor for about 15 months now. Its a Laka, made by Vintage and has always had a very nice tone. I have noticed lately that it seems to have a slight buzz especially on the first string. Everything looks fine with no visible distortion etc. It is fitted with Aquila strings but they were fittede from new. I seem to remember reading somewhere on here that the strings should be changed frequently, so could this buzzing mean that I should change the strings?