I have two Telefunken AU7 tubes which run the line stage of my Conrad Johnson preamp. I’m not sure how long they’ve been in the preamp, maybe a year and a half,
The preamp is a vintage model which was modded by CJ with Teflon caps.
Do I need new tubes?
Until recently, when I turned on my rig it immediately sounded full bodied and rich. In the last few weeks I’ve noticed it doesn’t reach this state immediately, but rather until at least after an hour. From then on it’s fine.
Is this a sign my preamp tubes are aging? My amp is solid state and always on.