Toroidal vs EI power amps any difference.

https://www.mpaudio.net/post/advantages-toroidal-transformers

Toroidal transformers look more techy. They are more expensive to wind. 
 

That’s it. No technical superiority.

Toroidal transformers are quieter to a point, but the larger they get the more susceptible they are to DC offset. I was told it starts to be more common  in toroidal’s over 300va. They can start humming or buzzing because of anything from a space heater to LED lights, especially when they are variable lights.

@jaytor - exactly.  As a manufacturer we use toroidal as we feel they have less noise.  When I met the Luxman representative about 5 years ago, he told me that Luxman switched to EI as they felt in their tests they performed better.  We have not done a comparison but in our experience we use toroidal in our tube components.

Happy Listening.