2. amps-preamps
  3. 177376-1660

Disappointing short life of NOS preamp tube

Being sarcastic really.

I only got 7 years out of  50's 12au7 RCA black plate. That may indicate 5 more randomly futzing out the rest of this year.

With the state of tube pricing now, tubes definitely not on my list of unnecessary audiophool spending.

I was really hoping these things going for 20, especially them just being preamp tubes, not a power tube. Fortunately, I have one more for backup, plus the 6 stock tubes in the shoebox.

Such is life. I'm more impressed by my relatively quick troubleshooting, avoiding severe neurosis. Less than 5 minutes-patting myself on the back, and praise from the boss.

.

tablejockey
tomcy6's avatar
tomcy6
2,597 posts
 

As George Harrison said, All Things Must Pass.

I guess you should be glad it was just a tube and not you.

facten
2,882 posts
 

tablejockey - I may be wrong but my impression has been that preamp tubes are rated at 5-10,000 hours. Given your described usage you may have reached that over the 6-7 years

ghdprentice
7,127 posts
 

It sounds like around 5,000 hours.
 

I have heard NOS have long lives… but as a kid also remember taking tubes down to the tube tester at The local drug store. I suspect some over romanticizing. And of course “average life” has a bell curve distribution.

petg60
1,486 posts
 

Fortunate that your pre is not pushing tubes hard, considering also the on off cycle.

Sad moment when they go and wonder if the new pair will sound the same.

 

 

audioman58's avatar
audioman58
4,194 posts
 

7 years is a long time for any tubes , plus you don’t know how your amp company bias the voltage or run the Ma voltage , power tubes 3-4000 hours 

small tubes like Tele , Siemens are 10,000 even bendix,  some ge 5 stars are tough military speck,  but nothing guaranteed with tubes , todays tubes far worse.

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