I got this tube with my GTA pre back in Dec (Thanks Russ). This is the first tube I tried in it and it was a bad experience. It gave me a headache. The sound was horrible. Too much mids, annoying highs and too much sibilance.
Since then, I've been using a Mullard and GE 6DJ8. They're great sounding tubes. Similar sound but the Mullard is better. It was more lean but had that extra air and 'open sound'. The GE is very warm and enjoyable to listen to.
I tried te JAN Philips a few more times in between but couldn't stand the sound. I hated it.
Then 3 days ago, I popped it back in just for fun. Still, I wasn't impressed. After about 5 hours of use, the sound started to improve. Sibilance was gone and the mids didn't dominate anymore. Now I'm starting to get excited. I left it running last night with full B+ to speed up break in. Now this little sucker sonds nasty! BEAUTIFUL sound! I love it. It's biggest strength is bass and dynamics. Soundstage is very big. I was listening at high spl earlier today and I'm still blown away. I love it when the dynamics build up to a climax and it feels like a speaker driver is about to fly out and hit your in the face. The JAN Philips is one bad ass tube!
Anybody know if the green and blue label JAN Philips is the same? I know the blue label one is made by Amperex. I have the green label.