Joe <j...@jretrading.com> writes: > For recording, good signal to noise ratio is important, and the four or > five internal cards I've used over the years have all been very poor in > this respect, maybe in the low 40s in dB. > > USB devices I've tried have had much less noise, particularly if the > audio ground side is linked to the tower case independently of the USB > cable.
The inside of a P.C. case is a hostile environment when it comes to EMI (Electro-magnetic interference.) The worst issues I have had are ground loops between the P.C. case and other grounded devices in which there are a few millivolts of AC difference between the two so-called Earth connections. That is why recording studios and broadcast stations usually use ballanced lines for all their audio connections. Martin