Try a brickwall surge protector. Use the 20 amp version. You will get top notch surge protection. The brickwall does provide line filtering but it is not as much as a lot of the other conditioners. A reconditioned one should cost about 279.00
Surge Protection and line conditioning
I just had a negative experience with a line conditioner and no longer want one for my system. I heard a little more detail but at the expence of my soundstage and an overall thinning of the music. Anyway, I would like to know if a surge protector without line conditoning would be the right choice if I want protection without the line conditioning. In short, do surge protectors generally leave your sound alone?