Ok, so in the last couple of months, my amo has been making a lot of excess noises(humming, buzzing, ringing, etc). I'm using a Fender Hot Rod Deluxe and a Wampler Triple Wreck distortion pedal. It makes these noises with and without the pedal turned on. Also, I've noticed my tone has gone downhill, it sounds muddy yet the high notes sound very shrill and harsh. Sometimes, the sound will go off completely while I'm playing. I got the amp about three years ago, and havent changed the tubes since I got it, so I think that could be the problem. I'm kinda new to this stuff, so any help would appreciated.
Definitely a good place to start, the tubes can make it sound brand new. Best bet is to get a matched set for the power valves, most companies do this and it means you don't have to worry about biasing. The preamps can be mixed and matched. Usually the first one is the stock clean tone, then the second adds a gain stage and I can't remember what the third one is lol
Find a place to have your tubes tested. One bad preamp or both power tubes could be at fault.
"Your sound is in your hands as much as anything. It's the way you pick, and the way you hold the guitar, more than it is the amp or the guitar you use." -- Stevie Ray Vaughan

"Anybody can play. The note is only 20 percent. The attitude of the motherfucker who plays it is 80 percent." -- Miles Davis

Guthrie on tone: https://www.youtube.com/watch?v=zmohdG9lLqY