I came across this article on the net and remembered that Nelson Pass said the same thing once about the sound effect of transformers used, rather than the actual tubes.
http://www.hawestv.com/amp_projects/amp_solid_tube/tube_sound1.htmThis site also mentions that transformers impart warmth or a mid range boost(sounds almost like an EL34 description).
"Audio transformer effects:"
"Audio transformer sound may be the most important component of so-called “tube sound.” The transformer launches a midrange boost, slight ringing, and even harmonics."
I then realized that all of the equipment that Ive liked and kept had a transformer.
In my case, the RME DAC makes the violins in an orchestra sound monotone and from a much smaller soundstage. Im wondering if it is because it lacks a toroidal transformer or linear power supply.