2. amps-preamps
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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
joes44's avatar
joes44
129 posts
 

When you look at it from that perspective, This journey and or hobby isn't really that expensive, When you add up all the hours years of enjoyment you get from a component that you love the sound of, or the synergy of a well balanced complete system, I think it's well worth it,,,,,,,Then again I don't want to pay for any exorbitantly high.prices.

mulveling's avatar
mulveling
1,896 posts
 

7 years / 5,000 hours is OK. Where’d you get the tube from? Any chance it wasn’t really NOS? To be fair, 12AU7's get a lot hotter than say 12AX7.

tablejockey OP
3,894 posts
 

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.

 

mulveling's avatar
mulveling
1,896 posts
 

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

I actually wonder that. Not sure there’s a guarantee of being "NOS", or whether that would even matter except for power tubes. That said, I’ve bought many, many tubes from Brent over the years and I appreciate his service and selection. He’s got lots of really nice exotics you can’t find elsewhere, except for taking gambles on the ’bay. Brent’s tubes always test good and sound great! He doesn’t make mistakes. No bum tubes. He even takes care to generally select clean looking tubes.

If you got 10,000 hours on a 12AU7 I think that falls into "great job, little tube" territory :) 

tablejockey OP
3,894 posts
 

"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. 

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