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  #17  
Old November 29th 19, 11:09 PM posted to rec.audio.pro
Phil Allison[_4_]
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Posts: 483
Default Input transformer for Spectra Sonics 101 preamp

wrote:

-------------------------
>
> >
> > ** Bull****, it ain't the same card.
> >
> > An input tranny that gave 10dB more gain would reduce the impedance
> > to 60 ohms. Way to low for any modern mic.
> >
> >
> > You won't take no for an answer - will you ?
> >
> >

**------------------------------------
>
>
> 10dB effective gain would require a 3.33:1 turns ratio



** 10dB = 10^0.5 = 3.16


> which would reduce the Z from 600 to about 180 Ohms.



** Absurd since impedance varies with the SQUARE of the turns ratio.

Plus defies "conservation of energy" as +10dB is a 10 times power
increase so the same voltage must be fed into a load resistance 10 times lower.

From 600 to 60 ohm.


..... Phil

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