Dr. Joan Bushwell's Chimpanzee Refuge

Super Low THD+N

On the audio front, National Semiconductor, long a player in analog semiconductors, has announced a couple new op amp families producing a total harmonic distortion plus noise spec of 0.00003%. These devices are aimed squarely at higher end audio applications and also offer a very low voltage noise spec of 2.7 nanovolts per root-Hertz with a flicker noise corner of 60 Hertz. I find these numbers to be pretty impressive, especially considering a starting price of $1.35 per unit in 100′s (up to about $10 depending on package and other details).

During my college days it was something to find devices with THD specs much below 0.1%, and even the best distortion analyzers were at least an order of magnitude above these little op amps. Also, “low noise” devices rarely broke the 5 nV barrier (the venerable 5532 comes to mind) and they almost always had a lower noise corner frequency well above 100 Hz.

In spite of the ready availability of low cost yet high performance analog semiconductors, I am continually amazed at the piss-poor audio quality that some people seem so happy to accept these days (highly compressed MP3s, “phone” audio, cheesy headphones, car subwoofers that are effective at pumping out 70 Hz tones and little else, etc.). We’d have killed for gear with the sort of quality now available. I mean that literally. Killed for it. Not necessarily other people (well maybe, in some cases), but animal sacrifice wouldn’t have been automatically ruled out.

Courtesy of Audio Design Line.

Comments

  1. #1 Ick of the East
    August 3, 2007

    Sure, people can and do settle for sub-par audio.
    But then there is the other extreme that always bothered me; People who would talk needles and cables and THD and Hz and MHz and WHATSITz and never get around to talking about the music that they were listening to.

  2. #2 Dunc
    August 3, 2007

    THD isn’t a great measurement for audio use IMHO – not all harmonics are equal. It’s the distortion spectrum you really need to know about. Not that I believe anyone can hear distortion down at < 0.1% anyway – unless it’s higher-order odd harmonics (9th order harmonic distortion is hideous). Of course, I’m a valve-head, so I would say that… ;)

  3. #3 Dunc
    August 3, 2007

    Goddamn unescaped less-than… That was supposed to say:

    Not that I believe anyone can hear distortion down at less than 0.1% anyway – unless it’s on higher-order odd harmonics (9th order harmonic is hideous). Of course, I’m a valve-head, so I would say that… ;)

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