This is quite untrue if you understand the math behind it
        -The output signals from the amps are added together nicely because they are all in phase
        -The noise generated in the preamps you can compare to random numbers rangin from positive to negative **add them all up and voila** the average will be less than the peak to peak noise of a single preamp

Peter
	

----------
From:  Paul B. Webster VK2BZC[SMTP:paulb@MIDCOAST.COM.AU]
Sent:  Saturday, November 29, 1997 5:06 PM
To:  PICLIST@MITVMA.MIT.EDU
Subject:  Re: Serial Sonar Unit (SSU) - Noise performance

Peter van Hoof wrote:

> An additional tip
>
> Noise cancels out (partially) in parallel amps, this works especially
> well in preamps where you can hang several amps to an input signal and
> (with series resistors) tie all outputs together

  Sorry, I just can't accept this statement in regard to front end
noise.  In fact I am sure the opposite is true, as when you parallel
amplifiers, you necessarily reduce the input signal level to each by the
split factor, 3dB for two, and make the noise WORSE by that amount.

  Cheers,
        Paul B.