I note that the ADC board uses the computer supply lines. These can 
be quite noisy. What noise do you generally see with the input line to 
earth?
>
>   Chris Chapman

I just did a very crude noise test: I unplugged the output of the filter 
(which is the input to the A/D in the PC) and shorted it.  So, with a 1 
metre cable attached I got mostly +/- 1 LSB and sometimes +/- 2 LSBs.  I 
think that's pretty good, considering.

Cheers

Ian
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