Ribbon mic hiss (yes, it's the mic) -- ideas? Impedance issue maybe?

[emrr]

It's impossible to tell, but as others have said you may be listening to nothing other than the sensitivity difference.  It'll be nice to know.  Though it does sound like you have a higher-Z output too. 

 

[midwayfair]

I wrote an e-mail to Rick W at Austin and among his suggestions was reflowing the solder joint on the red and black wires at the motor. I'd examined them to make sure they weren't cold, but the black one WAS looking a little cruddy so I hit it with some solder.

The hiss is almost entirely gone now. Did a wee bit more cleaning and I'm re-setting the copper to the motor right now, but a quick before and after recording confirmed that the hiss is almost 8dB lower, and the rest seems to just be the pre.

Big ups to Rick for standing behind his kit and for floating the suggestion when all else had failed.

Also thank you everyone in this thread for the education and Jon @ Shiny box for more help by PM.

 

[abbey road d enfer]

Since a dynamic mic doesn't generate hiss on its own, I was afraid something might have been wrong with it.

But it does! Just the fact that it's source impedance is not zero makes it a Johnson noise generator. In addition, its diaphragm being coupled with ambient makes it picking the sound of air molecules hitting it (thermal agitation). Not counting airborne noises...