Kde je firma Vishay?

[auro]

Doufam ze reply neni flame. Jen bych poukazal ze onech 64bit
ktere prezentuje odpovida SNR 385 dB. Tak nevim nevim zda
kompletni zesilovaci retezec muze teoreticky dosahnout takoveho
odstupu ... Pri citlivosti napr. 1V to znamena sum na
urovni 0.000001 pV. Kvalitni OZ maji 1nV/Hz^-1/2.
Mam pocit ze autor pocital POUZE s tepl. sumem na odporu
1ohm (10^-23) pro 300K a rirkou pasma zesiku 1Hz.
Pak to vychazi na onech 64bit. Pokud pouzijete alespon jeden
odpor 10k a sirku pasma 20kHz pak mame sum 10^-14. Tech
odporu tam bude vic a zesileni retezce bude alespon 40dB
takze u hoooodne super zesiku bez elektronek a tranzistoru
;-) jsme na sumu 1nV. A to je 30bitu.
Tak nevim - prijde mi to jako manipulace s cisly. Kdo chce mam
tu PDF o castem "misuse" Shannonova teoremu kdy lidi doplnuji
do vztahu nesmyslna cisla a pak jim vychazeji nesmyslne udaje.
devik

On Thu, 3 Oct 2002, Jaroslav Lukesh wrote:

> Jen pro informaci, no flame prosim.
>
> ----------
> | Odes?latel: Grant Richter <grichter@asapnet.net>
> | Komu: synth-diy@dropmix.xs4all.nl
> | P?edm?t: [sdiy] Information Reduction in Digital media
> | Datum: 2. ??jna 2002 12:40
>
> After reading the Rupert Neve interview in "Tape-Op" magazine, I really
> started to research the basic information content of analog signals.
>
> My experiments with 24 bit converters and Spectra-Lab software have shown
> that even a fairly crappy analog design running from +/- 15 volts
> (breadboard), has an unmeasurable signal to noise ratio at 24 bits.
>
> In other words, even simple analog really does run at a much better
> information content than even a good 24 bit A/D converter can resolve.
>
> For reference, Claude Shannon's original 1948 paper on the mathematics of
> communication can be accessed at:
>
> http://cm.bell-labs.com/cm/ms/what/shannonday/shannon1948.pdf
>
> It is interesting to note that Mr. Shannon never realized his work would be
> interpreted as broadly as it has been.
>
> Some information scientists seem to think that Boltzman's constant sets a
> basic limit on the thermal representation of information content. The
> Boltzman constant is defined by Joules per Kelvin, and a Joule is just a
> Watt-Second by another name. Also the audio 0 dB point is specified as 1
> milliwatt into 600 ohms.
>
> Doing fast sloppy math, a 1 milliwatt-second source has a thermally limited
> information content (at room temperature 300 deg Kelvin) of something like
> 2^64 bits per second.
>
> This is WAY better than the 2^32 bits per second used by the best digital
> media (remember, half of 2^64 is 0.5 x 2^64 NOT 2^32).
>
> So the general feeling that analog audio sources are cognitively different
> than digital sources would seem to be supported by these ideas from physics
> and mathematics.
>
>
>