Yes, I'd give it a few days - especially if you have some sinus issues. Otherwise, such a marked change would seem quite bizarre. If the tubes are still burning in, they can go "backwards" in sound quality for a while, but I wouldn't expect it to be so pronounced. I doubt the Bill Withers volume slip caused any damage - it certainly wouldn't have to the tubes themselves - if anything it would damage the headphones, but unless they sound distorted, it would be unlikely for that to cause a bass reduction only. I'd say a temporary ear condition is the most likely culprit. Give it a couple of days and see how you go. Good Luck !
OK well yes I mean I have hardly burned them in. I mean I have no idea how much use these had but supposedly they've been collecting dust for decades.
If they go backwards because they are still being burned in, then OK.
I wouldn't be surprised if I haven't even cracked 100 hours yet, maybe not even 50. That includes my headphones too.
So if I am really going to see that much of a dramatic difference at 100 hours, then I'll try to burn them in over the next 2 weeks.
Yes - give them 100 hours before worrying too much ... they'll probably still change a little after this time, but at least by then they should have largely stabilised as regards sound quality. New Old Stock tubes and tubes pulled from testing equipment often even sound noisy and distorted till they have been "run in" a bit.
Edited by NinjaHamster - 11/18/13 at 10:57am