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Old November 7th 19, 10:57 PM posted to rec.audio.pro
Phil Allison[_4_]
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Default overvoltage on audio circuits - Noname.jpg (0/1)

Scott Dorsey wrote:
---------------------


> >
> >> 4. All the GkTB equations we were forced to memorize in school are useful at
> >> RF but not useful in a mismatched low frequency world.

> >
> >** False. Johnson noise is dominant in any resistive source situation.

>
> Resistive source? An SM-57?
>


** Run an impedance test yourself.

From a few hundred Hz up to 15kHz, it is nearly flat.

There is a broad peak around 120Hz IIRC.

Essentially a 270 ohm source.

The internal auto-tranny just ups the value by a factor of 20 from the 13 ohms capsule.

Reason why makers use a simple resistor for pre-amp specifications.

And the type does not matter !!



.... Phil







I think maybe this is where one of the problems
> is located.
> --scott
>
>
> --
> "C'est un Nagra. C'est suisse, et tres, tres precis."


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