Jim Lesurf wrote:



The IM and THD charts that come with the manual are blank
and marked "Disclosure prohibited 4.11.1974"


I must confess I burst out laughing when I read that! Did they think the
detailed distortion performance of their amp was a 'trade secret' and that
no-one should be allowed either to know the spec or measure it for
themselves?!


** The word "prohibited" ought to tell you there was an FCC law in the USA that prevented making such disclosures.

The same FFC law allowed only continuous RMS power specs and then after a 1/3 power pre-conditioning session for 30 minutes.

The original law was Draconian and eventually became relaxed.



..... Phil