I am puzzled by the fact that I did not notice the sound change when the tube is not glowing.
What are the options? Is replacing one tube all I should need to do? What advantage might a "matched quad" offer?
The tubes are EL34WXT SOVTEK. I have the original driver board, and I'm going to stick with that for now.
Recommendations to try another brand of output tubes for sonic change are welcome.
Thanks in advance!