Single ended transformer grounding question

[Captn Dave]

I picked up a single ended EL84 amp with power supply problems that were easily solved, but while working on it I noticed that the negative output leads from the output transformers are not grounded.

The previous owner had installed new 5 way posts and omited the grounding either intentionally or by carelessness.

I think the safety issues speak for themselves and I intend to correct this, however I was wondering if there is some benefit or ungrounded application that I am unaware of that would make this setup either beneficial or necessary?

Thanks for your thoughts.

 

[HollowState]

I was wondering if there is some benefit or ungrounded application that I am unaware of that would make this setup either beneficial or necessary?

Grounding of the speaker common side is necessary if negative feedback is taken from a speaker tap. For safety issues it is also good in case the secondary shorts to the primary, even though this is very rare. However, it two amps were used in bridged fashion, then floating the speaker terminals would probably be necessary.