Have you got the Carbon or waiting? They do look rather solid. I’m wondering about any noise from it on the th900. Probably very quiet? Once you know that low level hiss is there, it is difficult to not notice because you kind of obsess over it. (Well, if you’re like me) Actually, I’ve just swapped over to my th900 and they really do sound remarkably open for a (supposedly) closed headphone. It’s not exactly closed I guess but the sense of space is lovely with them. Speaking of sensitivity .... I’m feeding an Ifi amp with a digital signal and for the th900, I have it on its lowest gain plus the extra attenuation underneath (iem match on ultra sensitive) and the headphone is perfectly loud enough at 12 o clock.