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

@inna - 

From the Stereophile review ... 

Inside, all signal paths are kept as short, straight, and direct as possible in relation to the front and back panels, with power tubes and output transformers to the rear, and a centrally located switch in front of the power transformer to choose between ultralinear and triode operation. To the left are four 12AX7 tubes (two for the line stage, two for the moving-magnet/high-output moving-coil phono stage), and on the right are three 12AU7 driver tubes.

So I guess my question would be, if you are not using the phono, are those tubes engaged and does it matter whether they are good or not.  

Rich 

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.