Jane;

I will put a case of beer on power supply routing on your prototype.

All audio and digital grounds must be kept seperate.  Return them
seperately to the central power point with a big filter cap at the
center.  Never mix ana and digi together.
(the secret is not wire gauge, but the fact that digital switch currents
are passing through the same ground traces that you are using for your
analog circuits).

Also, add the obligatory 0.1 mic caps everywhere.  But they will not
make up for ground layout.

Chris Eddy

Jane Ifurung wrote:

> Helpppp! I had my circuit wire-wrapped and found out
> that it's so noisy. My project is a voice multiplexer
> and I have subscriber line interface circuit(SLIC),
> codec, relays, transformer, and logic ICs. I did not
> use bigger wires for the power supplies.
>
> Any idea what caused this and ways how to reduce the
> noise? Any site that would be useful?
>
> I used vector board and no ground plane.
>
> Hoping for your answers.
>
> =====
> *~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~
> Jane Ifurung
> UP Diliman, Quezon City
> 920-5301 loc 5854
> (632)731-3545
> jifurung@eee.upd.edu.ph
> *~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~
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