[sdiy] reverse biased NPN vs Zener diode for noise...

[Oren Leavitt]

Find old zeners from the 1960s, and about 8 volt or higher. You will 
likely find some really nice noise makers. Modern zeners are made with a 
different process that does not yield as much noise.
The fun with "old" zeners is that each doide has its own individual 
character, color and grainy-ness. Don't be surprised if you find 
yourself giving your diodes names :-).

- Oren

nicolas wrote:
> I haven't done any comparative testing, but the advantage of the zener diode is that you can order one off the shelf and it will have a known voltage drop and fairly predictable noise character.  On the other hand using a transistor you will have to experiment a bit, maybe adjust things to suit the voltage drop you find or test several transistors to find one in the right range.  My understanding is that if you do manage find a suitable transistor it will give you a bit more noise at a somewhat lower voltage drop than a zener.  With zeners, use the highest voltage you can accomodate because below 10V they aren't so noisy.
> 
> Cheers,
> Nicolas
> 
> --- On Fri, 30/10/09, Benjamin Budts <mailing at gigaspeeds.be> wrote:
> 
> 
>>From: Benjamin Budts <mailing at gigaspeeds.be>
>>Subject: [sdiy] reverse biased NPN vs Zener diode for noise...
>>To: "synth-diy DIY" <synth-diy at dropmix.xs4all.nl>
>>Received: Friday, 30 October, 2009, 3:13 AM
>>
>>Hi,
>>
>>I'm looking into building a noise module and I'm wondering
>>what the audible difference is between
>>reverse biased NPN based  vs Zener diode based... :-D
>>
>>Just wondering if there's somebody on the list who tested
>>this...
>>
>>Thx
>>Benjamin
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>>Synth-diy at dropmix.xs4all.nl
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>>
> 
> 
> 
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