The Audio Precision was very expensive professional equipment and while a lot better than the designs you found in the magazines back then, was still limited by modern standards
This link is interesting, looking like they thought -90 dB was hard then:
https://studia.elka.pw.edu.pl/FILE/21L/103A-TLRTM-MSP-BUA/pub/Ap/Audio_Measurement_Handbook.pdf
This link is interesting, looking like they thought -90 dB was hard then:
https://studia.elka.pw.edu.pl/FILE/21L/103A-TLRTM-MSP-BUA/pub/Ap/Audio_Measurement_Handbook.pdf
"Modern standards " and you link a 1993 advert for AP ?
Here is a more up to date link -
Audio Analyzers | Audio Precision(C) - The Global Leader
This thread is about thermistors and even way back then JLH ( and others ) could design analogue THD meters/oscillators to 0.001 % THD --I built them .
Here is a more up to date link -
Audio Analyzers | Audio Precision(C) - The Global Leader
This thread is about thermistors and even way back then JLH ( and others ) could design analogue THD meters/oscillators to 0.001 % THD --I built them .
The best Some low distortion oscillators use LDR technology for the amplitude feedback: http://www.janascard.cz/PDF/An ultra low distortion oscillator with THD below -140 dB.pdf
Very good Mark I downloaded it but back in the 80,s that chip didn't exist although even earlier I built one of the first versions of using a LED and from what I remember an old 60,s BJT with the black covering scraped off built into a sealed box to keep out the light .
It was in an old UK electronics magazine , at the time it was innovative for an oscillator after that it went quiet and then out came commercial versions I have always wondered what the designer did with the money ( I hope ) he made from it.
It was in an old UK electronics magazine , at the time it was innovative for an oscillator after that it went quiet and then out came commercial versions I have always wondered what the designer did with the money ( I hope ) he made from it.
