Hickamore...yeah the input stage, but I decided to use 4 matched GEs of the same vintage as they’re pretty cheap really. Maybe I got lucky but my original version Freya has never been noisy at all...tried various tubes and settled on NOS GEs...I have horn loaded speakers and you can put your ear right on the horn and no hum or buzz exists (my SEP tube amp is also very quiet). It’s absolutely a high end product, and an open mind can keep you from being influenced by the relatively low cost...I did a shoot out with an ARC tube preamp and a CJ, and all there (well, all 4 people anyway) thought the Freya sounded better (had the GEs in the thing), and two of these friends bought a Freya. By the way, I don’t think tubes take long at all to reveal their qualities...heat ’em up and go. Note that I don't think my Freya sounds "euphonic" or whatever people blame tubes for being, other than what seems to be more revealing of detail and somewhat more musically accurate...again, instantly noted when switching to one of the non tube modes, a thing that you simply can't do with any other preamp I know of.