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