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Re: New noisy mic amps!

Subject: Re: New noisy mic amps!
From: "Klas Strandberg" klasstrandberg
Date: Thu Aug 31, 2006 10:18 am (PDT)
Hi!

I have tried a kind of mono "solution", using only the PIP voltage from one=

recorder input to feed a single transistor amplifier stage and then feed
the signal from it to the other recorder input. It works, I get almost 20
db extra gain, - still running everything on PIP, - but I still get amp
noise added to the EM23 noise....
Besides, I like A-B stereo...

Klas.

. At 15:08 2006-08-31, you wrote:
>Sorry about all the problems you are having Klas. I feel I should remind
>people who are stuck with a recorder like this that our FEL 20dB 3.5
>Series Preamplifiers use plug in power and do work with all plug in
>power recorders we are aware of, including the Edirol R-09.  In fact
>here is an unsolicited example from a customer using the R-09 with a
>Sony ECM-717 - not a nature recording mic but a good example of how an
>external preamp can improve the performance of a noisy built-in preamp.
>The recording demonstrates without and with a 3.5 SJ preamplifier and
>has been level adjusted to approximately equalize the clock ticks:
>
>http://www.micbooster.com/movies/edirol.mp3
>
>I should point out that these preamplifiers *do not* pass on the plug in
>power to the microphone (as Klas knows there is just not enough
>available), so they will only work with self powered, dynamic or ribbon
>mics, or a  mic with a battery box.
>
>Nick Roast.   FEL Communications.   http://www.micbooster.com
>
>--- In  Klas Strandberg <>
>wrote:
> >
> > Hello everybody, bad news again:
> >
> > Here on this list I claimed for a long time that ordinary MD mic
>inputs
> > were good enough if only the microphone had a reasonably high
>output, like
> > the Telinga EM23.
> > Rob and others took up this thread and found it basically correct.
>(??)
> >
> > Then something happened:
> >
> > Suddenly some recorders could not provide enough plug in power! The
>first
> > model was a Sharp MD released 2003. When using a low-noise FET IC,
>like the
> > one I had been using for years in the EM23, the voltage went down
>below 0,7V.
> > I thought it was only this Sharp, and warned about it at this list.
> > Then .... it seemed as all new Sony HiMD's were the same...
> >
> > Some wise guy in Japan seems to have realized what was happening, and
> > re-designed the FET-IC into a version using less current. I got hold
>of it,
> > I could test it and all was well. Now this low-current FET-IC is in
>all
> > EM23's and the HiMD plug in power is high enough.
> >
> > But of course I didn't like this new "Sony-style" of having such low
> > current capacity of the plug in power voltage.
> > iRiver, for example, went the other way and stepped up the 1,5v
>battery
> > voltage up to some 3v.
> >
> > Then came the new Edirol R-09! Worse than anything before it!
> > I tried every possible way to make a plug in power mic which had juice
> > enough to compensate for the low sensitivity and terrible noise level.
> > In vain.
> > You need an extra mic amp stage and a output stage providing low
>impedance
> > and external battery voltage, at least some 6 volts, preferably 9.
> >
> > Making very thorough experiments, I found that two other recorders
>were the
> > same - the Edirol R-1 and MT 24/96. Noisy, but more acceptable than
>the
> > R-09. With maximum output voltage from the EM23's internal FET-IC, the
> > recorder mic amp noise is louder than the self noise of the EM23.
> > A extra mic amp, output buffer and battery in a little plastic box
>solved
> > the problem.
> >
> > But: What about other new recorders??
> > Before: Most recorders were very alike, having good mic amps.
> > Now: There are good ones and really bad ones. I hate it!
> >
> > Isn't it true any longer that "MD mic inputs are good enough"??
> >
> > Rob?? Others?
> >
> > Klas.
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > At 17:16 2006-08-30, you wrote:
> > >Hi, can anybody recommend me an low noise external stereo mic for
> > >recording soft ambiances with
> > >the Edirol R-09?  I would prefer it worked with the PiP of the R-09,
> > >which as I am told is about
> > >2,6V. For me, the recording of louder ambiances with the internal mic
> > >works fine.
> > >
> > >I've red here about two Shure WL183 modifying them so they work with
> > >PiP, which is quite
> > >interesting for making binaural recordings.
> > >Would this also be possible with two Sennheiser ME2? I can have two
>of
> > >them but I don't
> > >know if they perform better or worse then the WL183.
> > >
> > >Thanks,
> > >
> > >Igor.
> > >
> > >
> > >
> > >"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: 
> > website: www.telinga.com
> >
>--- In  Klas Strandberg <>
>wrote:
> >
> > Hello everybody, bad news again:
> >
> > Here on this list I claimed for a long time that ordinary MD mic
>inputs
> > were good enough if only the microphone had a reasonably high output,
>like
> > the Telinga EM23.
> > Rob and others took up this thread and found it basically correct.
>(??)
> >
> > Then something happened:
> >
> > Suddenly some recorders could not provide enough plug in power! The
>first
> > model was a Sharp MD released 2003. When using a low-noise FET IC,
>like the
> > one I had been using for years in the EM23, the voltage went down
>below 0,7V.
> > I thought it was only this Sharp, and warned about it at this list.
> > Then .... it seemed as all new Sony HiMD's were the same...
> >
> > Some wise guy in Japan seems to have realized what was happening, and
> > re-designed the FET-IC into a version using less current. I got hold
>of it,
> > I could test it and all was well. Now this low-current FET-IC is in
>all
> > EM23's and the HiMD plug in power is high enough.
> >
> > But of course I didn't like this new "Sony-style" of having such low
> > current capacity of the plug in power voltage.
> > iRiver, for example, went the other way and stepped up the 1,5v
>battery
> > voltage up to some 3v.
> >
> > Then came the new Edirol R-09! Worse than anything before it!
> > I tried every possible way to make a plug in power mic which had juice
> > enough to compensate for the low sensitivity and terrible noise level.
> > In vain.
> > You need an extra mic amp stage and a output stage providing low
>impedance
> > and external battery voltage, at least some 6 volts, preferably 9.
> >
> > Making very thorough experiments, I found that two other recorders
>were the
> > same - the Edirol R-1 and MT 24/96. Noisy, but more acceptable than
>the
> > R-09. With maximum output voltage from the EM23's internal FET-IC, the
> > recorder mic amp noise is louder than the self noise of the EM23.
> > A extra mic amp, output buffer and battery in a little plastic box
>solved
> > the problem.
> >
> > But: What about other new recorders??
> > Before: Most recorders were very alike, having good mic amps.
> > Now: There are good ones and really bad ones. I hate it!
> >
> > Isn't it true any longer that "MD mic inputs are good enough"??
> >
> > Rob?? Others?
> >
> > Klas.
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > At 17:16 2006-08-30, you wrote:
> > >Hi, can anybody recommend me an low noise external stereo mic for
> > >recording soft ambiances with
> > >the Edirol R-09?  I would prefer it worked with the PiP of the R-09,
> > >which as I am told is about
> > >2,6V. For me, the recording of louder ambiances with the internal mic
> > >works fine.
> > >
> > >I've red here about two Shure WL183 modifying them so they work with
> > >PiP, which is quite
> > >interesting for making binaural recordings.
> > >Would this also be possible with two Sennheiser ME2? I can have two
>of
> > >them but I don't
> > >know if they perform better or worse then the WL183.
> > >
> > >Thanks,
> > >
> > >Igor.
> > >
> > >
> > >
> > >"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: 
> > website: www.telinga.com
> >
>
>
>
>
>
>
>
>"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: 
website: www.telinga.com







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