Jenny, given the same recorder, mikes and even cables and connectors can
introduce or remove noise. Neal did a demonstration of the Rode NT-4 mike
using both of the supplied cables, one has standard XL connectors for the
Sound Devices type units, the other cable had the mini plug for a
computer's mike input. There was a noticeable increase in noise with the
cable with the mini plug.
Of course, better mikes have far lower noise floors and, if the preamp and cable are up to par, the quieter mike will produce a quieter recording. I make mhy podcasts with a fairly pricy mike, but as I said t he result is a dead quiet recording, except for the tiny noises around. I was hearing the hard disk access in my recorder on the recording, so had to get a compact flash card to record on so the unit would not use the hard disk, now the only sound is my beard hairs rubbing against the pop screen...well, I try to avoid that. [grin]