Thanks for your reply.
“Is the hiss always there?… or sometimes it is, and sometimes it isn’t?” No, its there all the time.
“Sounds like before you might have been using the onboard (front) mic… was there no hiss there?” Nope, hiss is not showing up on the on-board mic.
“Is the hiss in both left and right channels?… or just one of them?” Both. depending on the volume for each Chanel.
“Does the hiss vary in intensity when you turn the mic gain up and down? Or is it always there at the same level, even when you have that channel turned down to zero?” The hiss does vary in intensity when the volume is turned up/down. Its not there at zero.
Is it, and its level, affected at all by switching the phantom power on or off? Not really, possibly a little bit better on battery power, but really a unnoticeable change.
Is it, and its level, affected at all by switching the input type from mic to line in?
Yes. The hiss goes away completely, but so does the mic’s audio.
Hope this helps!
Thanks