Hi Paul--
By "unity" I mean the default setting on the 744T balanced line input
coming from the balanced line out of the Mix pre. Plain vanilla. No
gain, no cut.
You are blowing the circuits in my feeble (non) audio engineer brain.
If the SD pres have only 46 dB total gain, how can there be mic pres
made for ribbon mics spec'd at 70dB gain?
What is the 66dB gain spec about in the Mix Pre manual and why did SD
make the displayed gain settings in their units so misleading?
The 2.64dB difference is also consistent with 66 spec for the MixPre
and 68 dB as the SD 7xx displays.
The actual gain numbers don't concern me as far as comparison testing
topic goes. I would like to know the source of the 14 dB SD702 and
DR680 difference. I'll get back when I find out what Emil's settings
were on the DR-680. Rob D.
=3D =3D =3D =3D
At 7:14 AM +1000 8/23/10, Paul Jacobson wrote:
>
>On 21/08/2010, at 3:18 PM, Rob Danielson wrote:
>
>> Hi Paul--
>>
>> I don't have a rms multimeter or scope. These are the file
>>saturations I get:
>>
>> Pink Noise- > NT2000 -> Mix Pre at Full Gain -> Balanced Line Out/In
>> @ Unity -> 744T =3D -3.3 dB RMS
>
>Hi Rob,
>
>By unity I'm assuming 0dB indicated gain? This means you need a 0dB
>input to register -20dBFS, so effectively the input would require
>roughly +20dB to 0dBFS. In other words you are attenuating the input
>by around 20dB. With full gain on the Mix Pre this would mean you
>are recording with 66dB gain, plus 20dB attenuation, giving an
>overall gain of 46dB.
>
>>
>> Pink Noise- > NT2000 -> 744T at Full gain =3D -.66 dB RMS
>
>The 2.64dB difference you are seeing is very close to the 2dB you'd
>expect with the SD specified gain for the preamps i.e. 48dB.
>
>cheers
>Paul
>
>>
> > I haven't heard from Emil yet about the DR680 gain setting he used. Ro=
b D.
>>
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