I've got a Classic 60 and have biased it a couple of times, though it's been a while since I last did it, I'm overdue! The process is fairly straight forward, two important points though, you really need the Audio Research tool since it is very difficult to find a substitute. I know since I didn't get the tool when I bought the amp used. The other point is to be VERY careful when hooking the test leads to the test points. It's easy to short the leads and cause all kinds of havoc. You should practice hooking up with the amp off to make sure your test leads hook up securely and won't short out due to size or lack of insulation. One other thing, if the tubes aren't matched you may have problems getting the bias to match (I'm going on memory here, I don't have access to the manual right now).