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-   -   Extreme Low Noise Preamplifier 0,4 nV/Sqr(Hz) (http://www.diyaudio.com/forums/solid-state/79782-extreme-low-noise-preamplifier-0-4-nv-sqr-hz.html)

peranders 18th May 2006 08:00 AM

Extreme Low Noise Preamplifier 0,4 nV/Sqr(Hz)
 
http://www.beis.de/Elektronik/LNPreAmp/LNPreAmp.html

Have you seen this?

It's nothing new to use HF or RF transistors as low noise input transistors. Even Elektor had such a design many years back but this german has done a very good article about this.

AndrewT 18th May 2006 08:36 AM

Hi,
interesting and achieved way below (better than) his already good target.
Sounds like it will be worth following to see developments.

AndrewT 18th May 2006 10:55 AM

Hi folks,
any idea how to activate Uwe Beis' Email?

mzzj 18th May 2006 11:11 AM

Quote:

Originally posted by AndrewT
Hi folks,
any idea how to activate Uwe Beis' Email?


http://beis.de/Elektronik/EMail_Beis.html

AndrewT 18th May 2006 11:42 AM

Thanks Mzzj,
that link worked.

peranders 18th May 2006 12:15 PM

I have read Uwe's directions for emailing and although this is a matter of course, something that is obvious, many people should think more about how the write messages to strangers. The least you can expect is a message signed by the name.

Compare the directions from Rod Elliott

http://sound.westhost.com/contact.htm

john curl 18th May 2006 06:03 PM

The limitation of this design is the active noise injection from the current sources. Check it out.

peranders 19th May 2006 08:29 AM

Do you mean the ZD zener at the input?

Samuel Groner 27th April 2010 04:26 PM

T3, T5 and T6 sure contribute some noise, I can't tell off-hand though how large the contibution really is. With an undegenerated BJT input (not low-gmish JFET) second-stage contribution can usually be ignored.

Samuel

ontoaba 28th April 2010 10:22 AM

He should use S/N ratio noise measurement, because input impedance differ the noise, in this kind circuit.


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