Hey guys, im kinda new to this place and i figured this would be a good way to start me off...

My Head seems to have some feedback problems and im not sure what it is, ive ran it through three differant cabs but i currently dont have one, and its had the same feedback problem through all of them. It seems when i turn my level up to about a quarter or so, if my masters up to about half or so it starts to squeal and it doesnt matter how close i am. The only way to solve it is to turn down the level on my gain and then it dissappears, its not to much of a problem to me but i would just like to know if theres something i can do about it.