How do you know when tubes in the phono section of the integrated amp go bad..

I think, they are somehow engaged, but I don't really remember what Kevin said except that they should be there. He didn't say it didn't matter whether they were good or not.

Checking every week is a bit OCD. 😉 I wouldn’t worry about it. Low power signal tubes last decades. I’ve been using tubes for over 40 years and never had an electronic failure in a small tube.

Maybe he wants the tube there to keep the voltage constant, so as long as the filament lights up it should be fine.

imhififan, right, he did say something about voltage constancy, but I don't understand these things so I can't remember his exact phrase.

Thank you, this is going to be my working solution - if the filament lights up I am good.

In fact, I might put the turntable back in place in couple of years, so I will know even better. But I would have to replace those Brimars with Mullards or maybe RCA or Raytheon blackplates.

You might like the Gold Lyons. Preamp tubes last a long time. You could swap the locations every year. But I think you might notice the difference if a tube went bad.