benjie
I have restored both of my R2R decks, Techincs RS-1500 2 track and Revox PR99 MkII. And I can say without a doubt that there is no "euphoric distortion" generating circuit in either deck.I’m sure there’s no circuit in either deck designed to generate distortion, be it euphonic or "euphoric." The distortion - however slight or pleasant - is just a consequence of imperfect electronics.
I don’t think the term existed 35 or 40 years ago ... Sorry I am going to have to call BS on that one.You might want to do some research on this matter, which dates back to at least the 1940s. For example, see Brockbank, Weiss (if I recall correctly) from the IEEE journal. This is a very well-studied field.