[Eeglablist] line noise re-revisited...again

[Jose Luis Lasala]

i think that the noise is proportinal to the impedance of A/D. If you have 
low impedance you will have low noise.
You can add an amplifier with low impedance in the internal source.

Chiky

----- Original Message ----- 
From: "Paul Kieffaber" <kieffaberp at upmc.edu>
To: <eeglablist at sccn.ucsd.edu>
Sent: Monday, February 11, 2008 2:15 PM
Subject: [Eeglablist] line noise re-revisited...again


> Dear List,
> I was discussing the line noise issue with someone recently and a
> question came up regarding the point of introduction.  My understanding
> is that most line noise is introduced to the recordings through the
> cables between the electrodes and the A/D box or amplifiers.  Is there
> also a risk of introducing line noise with long cables between amplifier
> an the recording computer?
>
> Our hunch is that the digital signal in those lines is not susceptible
> to the introduction of noise like the analog signal between the scalp
> and the amplifier.
>
> Your thoughts and comments are appreciated.
>
> Paul
>
>
>
>
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