Thanks a lot for the explanation!
One must consider that each (condensor / electret) microphone already has a=
built in microphone preamplifier!!!
The most simple one is a Field Effect Transistor (FET) , but there is
usually (always?) a condensor over the source resistor an voila! - you have=
gain! You have a microphone amplifier! Usually there is much more than just=
a simple FET. The capsules which I use with Telingas have a three leg
FET-IC, probably with a lot of active and passive components inside of it.=
The signal from the FET-IC is then handled by a base filter and a source
follower, to give 200 Ohms output impedance. The PRO6 also has a voltage
stabilizer.
I guess one could put it this way:
"If the built in microphone preamp is good enough, why should you connect
an extra one??"
By "good enough" I mean enough output voltage with low enough self noise.
Remember, that all this text written about preamp noise, was written when
most recordists connected a dynamic microphone! The dynamic microphone is
just a membrane, a magnet and a coil - no internal preamp!
In those days you were always in trouble, with preamps not fitting the
microphone in question.
Today, I dare claim again, - with modern equipment - you only get into
mic-preamp noise problems when the output of the microphone (+ it's
internal preamp!! ) is too low.
My "antique" Tascam DA-P1 has quite average mic inputs. Still, when I
connect a MKH20, which self noise is as low as 10 dbA, all I hear is mic
noise, not Tascam noise..
Klas.
At 17:41 2005-04-15, you wrote:
>I'll try, though I imagine there'll be some debate about the
>interpretation of the results.
>
>Rob recorded a ticking clock and egg timer using various microphones,
>preamp gain settings, and in several cases, supplementary amps between
>microphone and recorder's preamp.
>The recordings were made using a MD recorder then transfered to a
>computer (I take it) and their overall sound levels were adjusted so
>that sound levels in the recordings are all about the same.
>
>In one comparison that I found informative, the same microphones (Rode
>NT4 XY) were used with different preamp gain settings (18 and 28,
>whatever that means) then received +24dB and +20dB in "post". The noise
>levels in these two recordings sound about the same to my (admitedly
>inexperienced --- plus I listened on cheapo speakers connected to a PC)
>ears. I take this as evidence in favor of your (Klas's) assertion that
>the preamp noise isn't as much of a problem (isn't heard as much) as the
>noise from the microhpone.
>
>In some recordings an additional +20 dB "booster" was used. I didn't
>notice a lot of improvement as a result.
>
>The quietest of all the samples was from Rode NT1A microphones, an MP2
>preamp and MD preamp gain of 28. Again, I conclude that the MD preamp
>isn't a problem but that the noise is primarily from microphones. (I
>don't know but I suspect that these NT1A's are more expensive/ higher
>end than most of the other microphones in this comparison. I certainly
>think this is the kind of recording I'd like to be able to make!)
>
>I hope this helps a little and will try to go into more detail if people
>want me to. I'm also looking forward to hearing other people's thoughts
>about this study and more than willing to agree that I'm just a novice
>at this sort of thing!
>
>I join others in thanking Rob for his efforts. The results were nicely
>presented and I feel he's done us all a great service by making this
>study available.
>
>Cheers!
>
>Steve P
>
>
>Klas Strandberg wrote:
>
> >For us antique modem users, can anyone tell in words what this test was =
all
> >about and what the results were?
> >
> >Klas.
> >
> >At 15:47 2005-04-15, you wrote:
> >
> > >Once again, Rob Danielson treats us to truth:
> > >
> > > > http://www.uwm.edu/~type/Mic%20Preamps/Mic&PreTransparencyTests/med=
ia/
> ><http://www.uwm.edu/~type/Mic%20Preamps/Mic&PreTransparencyTests/media/>
> > > > TransMic&PreTestsSor3_01.mov
> > >
> > >And again we see that TRUTH HURTS! This will take some serious
> > >pondering...
> > >
> > >Curt Olson
> > >
> > >
> > >
> > >
> > >"Microphones are not ears,
> > >Loudspeakers are not birds,
> > >A listening room is not nature."
> > >Klas Strandberg
> > >Yahoo! Groups Links
> > >
> > >
> > >
> > >
> >
> >Telinga Microphones, Botarbo,
> >S-748 96 Tobo, Sweden.
> >Phone & fax int + 295 310 01
> >email:
> >
> >
> >
> >
> >
> >"Microphones are not ears,
> >Loudspeakers are not birds,
> >A listening room is not nature."
> >Klas Strandberg
> >
> >
> >------------------------------------------------------------------------=
-
> -------
> >*Yahoo! Groups Links*
> >
> > * To visit your group on the web, go to:
> > http://groups.yahoo.com/group/naturerecordists/
> >
> > * To unsubscribe from this group, send an email to:
> >
> >
> <=3DUnsubscrib=
e>
> >
> > * Your use of Yahoo! Groups is subject to the Yahoo! Terms of Servic=
e
> > <http://docs.yahoo.com/info/terms/>.
> >
> >
> >
> >
>
>
>
>"Microphones are not ears,
>Loudspeakers are not birds,
>A listening room is not nature."
>Klas Strandberg
>Yahoo! Groups Links
>
>
>
>
Telinga Microphones, Botarbo,
S-748 96 Tobo, Sweden.
Phone & fax int + 295 310 01
email:
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