I got my HE-6's in the mail today!
They've only been in use/burned-in 4 hours. At first there was a lot of hiss'es and crackles but it's starting to go down. I think it's the tube in the EF-5 burning in but wanted to double check. Thanks or any help!
Oh, and rythemdevil was right, that clarinet was amazing. I'm listening to 2L's HarmOrgan Album and I feel like I am right in the church were they recorded it!
Some tubes will do that. The gas inside the tube is absorbed by the getter and their are impurities that some tubes have more than others that get burned off. Some tubes settle down great and some don't. Hopefully yours will do fine. I look forward to more impressions. Congratulations.