Disappointing short life of NOS preamp tube

facten-

I've never  cared/paid attention to tube hours, but the amp /tubes have served me well.

Over the 6 year period there have been random marathon weekends of near 24 hour service, after work, almost daily 2  hour dinner sessions, random times the amp has been accidentally left on weekends(not recommended, of course) and BLAST your ears sessions with friends. 

Whatever it equates to, I consider the tube serving  it's purpose. I have a daily driver 67 Mac tuner  with a couple of original tubes. 

USA NOS tubes for the most part are indestructible, but not 100% like anything manmade.

mulveling,

Yeah, I figure it was in the upper range nearing 10K hours. As said in the opening post, I'm just goofing on the fact they lasted "only 7 years."

I get most of my tubes from Brent Jesse, and trust his listings. If he say's their NOS, I rely on that.

"It sounds like around 5,000 hours."

ghdprentice- I''m  thinking the tubes are now somewhere in the 5-7K zone, so yeah

I'm not surprised to see one futz out now. 

Anyone remember buying the 5 pack when they were "new?"

"I actually wonder that. Not sure there’s a guarantee of being "NOS", or whether that would even matter except for power tubes."

mulveling- yeah, the "NOS" thing is roll of the dice. With preamp tubes, it may not be such an issue whether or not you're getting a genuine, unused "NOS" tube.

True NOS is something you actually purchased  from the local hardware or drug store for $1.87, tossed in a box in storage for the next 60 years, and you "discover" it.

I've been using some 50's  RCA 6L6G's (the low voltage coke bottles) also from Brent that were installed just weeks after the 12AUf7's. One just died the other day.

I'm  hoping to get another batch from him, and refresh all 8 needed.