audio research ls 2b popping noise?

After about five to ten minutes of warm up i get a loud pop out of the left channel. When i turn on the preamp i have the mute on and the volume set to 0 and after the 45 second mute goes on you should be able to listen to it but a loud pop will occur within the time mentioned above. I did just replace the tube about a week ago from a gold lion 6922 to a telefunken e88cc. After the pop no more pops occur until the next time i start it up, it didn't do this when i first got it. any advise would be appreciated.
Did you get a pop with the old tube or only the new one? If it's only with the new one, then try putting the old tube back in. If you only have a pop with the new tube, then it would seem the tube is at fault. I had an LS2 for a few years and never had any problems. It should be pretty reliable and reasonably quiet.
good advice, i went back to the old tube and no pop so i called the guy i got the nos telefunken and he said try putting it back in so i did and no more pop, maybe a bad pin contact. i also talked to an arc tech and he said try the same thing. anyway the preamp has been left on now for a few days and no more problems. i debated going back to my krill krc3 but the ls2 does sound way better.
Good to hear that. As I said, the LS2 is pretty reliable so hopefully you will now have a number of troublefree years with it.