With stock tubes I only get a bit of noise that I only can hear at the speaker ( a foot or so away). Polk LSi15 from a Adcom GFA-555(which is now died so I’m ampless).
Usually the load, speakers in this case, is what kills the amp, especially if you lost one channel. You need to be sure that your speakers are okay before you hook up another amp to them. A
Order up a Vidar or two to replace that Adcom. You'll be a happy camper.
After he makes sure that the speaker(s) didn't kill the amp!