i suspect that high end is a qualitative concept based upon a price threshold. that is at some price point a component is considered high-end. i'm not sure what that is.
on another note, the poster who listed the brand names of some high-end tube manufacturers, left our aesthtix, conrad johnson, audio note, lamm, navison and others.
on another note, the poster who listed the brand names of some high-end tube manufacturers, left our aesthtix, conrad johnson, audio note, lamm, navison and others.