Center tap or not

[K.A.B]

I have a stupid question but my excuse is that my stroke that I had a few years ago makes me sometimes hesitant because I have simply forgotten.

I am building a tube preamp and I use SMPS for the glow but now the secondary glow is not used on the main transformer my question is because it has two 3.5V with center tap that is connected if I want AC glow, my question is then should I connect the center tap to the chassis ground or not now that I use SMPS.

 

[K.A.B]

Since no one has dared to answer about center tap or not, I can now answer the question myself and my post can be archived.

Well, you don't need to connect the center tap to the chassis ground at all if you don't use that winding on the transformer. It's perfectly fine to leave it as is.

 

[rayma]

Yes, if you don't use a particular winding, it is not necessary to connect any of its leads.
But the voltage from the other secondary winding(s) will rise somewhat due to the reduced loading.

 

[K.A.B]

Although the voltage has increased, it is within the values suggested.

 

[rayma]

That should work, but be sure to fully insulate the ends of the unused winding leads,
in a way that will not degrade with temperature and age.