Yes they improved it as headphones were improved too... But why my Sansui alpha was able to beat the tube Berning amp for synergy with the K340 then ?
And if they improve so well the headphone too why is my K340 was able to smoke to a bin trash my 9 other headphones ? do you have an answer ?
Synergy matter ; and top flagship of the past are not trash nowadys.... Acoustic experience dont reduce to electronic design of the separate components ... We must also EMBED the components then we listen to them not to their price tag ...
Sorry i could not resist to answer to your common place "evidence" ...
Sansui was big for the military at the PX during Nam. They made a few good pieces back in the day but SS has improved considerably since then.