If you are referring to JJ/Teslas, not old Tesla's, the current production tubes are just not rugged, and/or the quality control is not perfect. In my experience using them in a CDP they have a warm tone with full but not tight bass and softened highs. Worth a few failures if this sound works for you.
The 6h23 is a rugged tube, typically low noise and it is not failure prone. cool, clear, linear tone. Too much so for some.
The good news is the JJ's are cheap and you can afford a few failures.
Hope that helps a bit.
The 6h23 is a rugged tube, typically low noise and it is not failure prone. cool, clear, linear tone. Too much so for some.
The good news is the JJ's are cheap and you can afford a few failures.
Hope that helps a bit.