[sdiy] Lego synth anyone?

[James Patchell]

No, this is a real effect.  First of all, two uncorrelated noise sources do 
not add.  What you get is the square root of the sum of the squares.  So, 
if you have two noise sources that put out 1 VRMS, the "sum" would be the 
square root of 2 (1.414).  Two signal sources, of course, add up 
algebraically.  So, the more transistors you connect together, the signal 
gain increases at a faster rate than the noise gain.

For a reference, locate a copy of "Low Noise Electronic Design" by 
Motchenbacher and Fitchen, page 249....

At 01:02 PM 1/17/2005 +0100, synthos at xs4all.nl wrote:

> > Paralleling transistors can lower noise as the signal is in phase, while
> > the noise is random and 'should' cancel out. A few transistors produces a
> > benefit...
>
>Is that a fact? Do you perceive it like that?
>If you add two noise sources, they add up. Being random, there
>is no such thing as cancelling out.
>
>Or, is this why resistors come in matched pairs ;-)
>(I like those 'three in a package' no-noise resistors!)
>
>
>Dave Krooshof
>
>Dendriet
>
>
>
>
>
>
>
> > H^) harry
> >
> > anthony wrote:
> >
> >> > In his BBD based delay module, Thomas Henry parallels some inverters
> >> for
> >> > increased drive. What are you trying to achive.
> >>

         -Jim
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