I’ll talk to the mfgr directly and watch/read what I find on my own (I have learned about limited suppliers/mfgrs and that there are few/er options that in decades before), but opening the door to any of you who have been in the tube world and may have thoughts to share. It’s my first tube amp and loving it, since it’s warming up the system very nicely - the other key pieces are a Pass 350.8, aurender n200, holo may kte, and Logan CLX Art speakers.
Thanks for sharing your knowledge and experience with a newcomer to tubes!
Edit: The amp was completely rebuilt by VAC about 2 years ago and we recently have heard some scratching noises when turning the system on, so assuming it might be time to swap them out.
Andy at vintage tube services in MI is also good. I use him and Brent Jesse