I had bought my violin last year. It is a used one, and one of the most consistent problems I am facing is the scratchy tones of the violin. I have a different one I use in my lessons, but the violin music wasn't as scratchy as the one I bought myself. I thought it may be a problem with the rosin, but it is not. I use Kaplan Premium for my violin, which is a really good rosin, but it still remained scratchy. It is not a string problem as well, as I have recently changed my E string, and the same problem remained. I tried using more or less rosin and yet, it didn't seem to get better. At this point, I practically have up. It has been a year, and it hasn't gotten better over time. Then how can I make my violin less scratchy?
Yeah, when I bought my first violin it was "really scratchy". A year later the scratch had completely disappeared! That was because the scratch had nothing to do with the violin and everything to do with the player.
As a beginner there is always a great temptation to blame the tools, the bow, the violin, the setup, the rosin, the shoulder rest (or lack of a shoulder rest if playing without). Been there, done that. But you need to learn that the first cure for any of these apparent tool-related problems is more practice.
If there really is a problem then it won't magically go away when you hand the instrument to your teacher and ask him/her to play. 999 times out of 1000 the "problem" does go away when you do that.
First bring it to your lesson so your teacher can evaluate it. "Scratchy" is not diagnosable over the internet :-( . It's quite possible your strings are dead, or cheap/lousy strings to begin with.
As a warning to others, I strongly suggest never buying an instrument without having your teacher or other local accomplished player evaluate it for you. You may have bought a plywood box worth $25 US, in which case it'll never sound good, for example.