Bigwavedave, whats the rest of your gears?
I was asking because 1201byl maybe right as SF Line 2 is very tranparent that you really can't hide anything from it.
I find the SF line series to be either you love it or hate it,due to it's ruthless nature of revealing everything.
I have a line 2SE myself that I bought a couple of months ago.I remember when I was breaking it in that it sounded like it has a head cold exactly like you described. I left it running for at 48 hrs straight (low volume)without listening to it, I was able to do it that long because I was so disapointed with my initial impression.
It was Saturday morning when I listened to it again.Oh Men,I'm saying to myself,"This is the Sonic Frontiers Line 2 SE that I was expecting" Everything just clicked.I absolutely love this preamp.
If your unit doesn't open up after 48 hrs of straight play I would suggest checking your tubes.
The rest of my gears if you're interested are
EMC 1,Line 2 SE,Krell FPB 200,Thiel 3.6,
NBS monitor series and Siltech cabling.FIM and NBS PCs.