|Does this sound like the sound of tubes going bad?|
Got home tonight and powered up the stereo. (Separate power amp and preamp, both tube.) Last listened to it two nights ago. There was a loud, constant cracking noise coming out of the speakers... and when I disengage and engage the mute, I get a loud thump/pop out of the speakers. After 1/2hr warm up, the cracking sound went away.
My amp auto-biases. Amp and Preamp are 5 mo's old. Amp has 4 KT88/6550s, 4 12AU7, and 2 12AX7 tubes. Preamp has 2 12AU7 and 4 6DJ8/6922 tubes.
Thanks for your observation.