Keep in mind that some tubes were designed for indefinitely long lifetimes. Western Electric made some of those... I believe that there are some under the Atlantic Ocean that would still work if fired up... might be urban legend?
The average consumer tube - 12AX7 etc, varies all over the map.
The real question I think that is valuable and perhaps implied in the original post is that tubes are not solid state devices. Both fail, but for different reasons. Tube characteristics do change with age and/or the way it is loaded and run (the voltage and current). Solid state not very much so far as we can tell.
Adcom 555s imho do not represent the best of solid state design or subjective sound, by the same token there are many tube amps that do not (imo) represent the best of tube design or subjective sound.
If there is an "advantage" to solid state it may be in that it will pretty much sound the same on day one as day 10,000... whereas the tube unit may or may not, and it may or may not sound different depending on the specific tube plugged in the hole.
If you don't want to use tubes, there are many reasons or excuses...
Just as there are many reasons or excuses not to use tubes...
_-_-bear
The average consumer tube - 12AX7 etc, varies all over the map.
The real question I think that is valuable and perhaps implied in the original post is that tubes are not solid state devices. Both fail, but for different reasons. Tube characteristics do change with age and/or the way it is loaded and run (the voltage and current). Solid state not very much so far as we can tell.
Adcom 555s imho do not represent the best of solid state design or subjective sound, by the same token there are many tube amps that do not (imo) represent the best of tube design or subjective sound.
If there is an "advantage" to solid state it may be in that it will pretty much sound the same on day one as day 10,000... whereas the tube unit may or may not, and it may or may not sound different depending on the specific tube plugged in the hole.
If you don't want to use tubes, there are many reasons or excuses...
Just as there are many reasons or excuses not to use tubes...
_-_-bear
Yes, I have proven that it is possible to take a new, unused tube from NOS to DEAD is as little as 5 minutes. I have also cranked some serious glow into a pair of Chinese 6L6GC's repeatedly for several years, and this pair served about a year in a Fender Bandmaster before I got them. They are still alive. I have also seen some of the same Chinese 6L6GC's fail in a few weeks of "nornal" use. I have also found plenty of NOS tubes that have never been used, but don't work because air leaked into them.
I have a reputation for blowing up some tubes (usually cheap TV tubes like the 98 cent 6BQ6's). No one talks about the "other George" because frankly he's boring. I was excavating some buried junk at an outdoor flea market several years ago when I found an old Sparton radio chassis in the dirt. $10 made it mine. Inside were several National Union globe tubes and a tag that said "all tubes replaced November 1929". The NX-483's found their way into my Tubelab SE amp where they still reside, making a very sweet sounding 2 WPC. OK, these tubes are over 80 YEARS OLD! Its safe to assume that your tubes will last somewhere between these two extremes. Just how long will depend on how well they were made, and how hard you run them.
In the 1980's Consumer reports rated the Ford Mustang as a car with below average reliability. They rated the Thunderbird above average. Since these were essentially the same cars, why the different ratings? Consider the demographics of the drivers. Who buys a Mustang and how do they drive it VS who buys a Tbird and how do they drive it. Notice the ratings of todays Buicks, and the identical Chevys. How are you going to drive your tubes, like a Mustang or a Tbird?
Pictures, poping the clutch at 7000 rpm on a couple of "Mustangs" All 3 tubes are still alive. The 6BQ6's dont work so well, but they were "dead" when I got them.
Attachments
I meant to say:
...Just as theree are many reasons or excuses not to use solid state.
ooops!
Hey, I did 40m CW for 2 years, every night with one of those 6BQ6's pulled out of a dead TV set. Built from the 1964 ARRL Handbook. I guess I couldn't afford a 6146!
spc and quality control
Quality control is only as good as the honesty of the graveyard shift production manager and the diligence of the upper management in wandering in to check at random times. US quality control took a huge jump up in 1943 when some Carnegie Steel executives and QC managers were convicted of manslaughter and sent to jail for a batch of steel that had good paperwork but sent a new ore boat to the bottom of Lake Superior with a broken keel of imitation "steel". SPC is a good tool, but it requires supervision on the part of the factory and the customer. Good product can be turned out in any country, but it requires the "brand" manager to check and keep checking, not fly out to somewhere comfy on Friday night and back Monday AM.
Quality control is only as good as the honesty of the graveyard shift production manager and the diligence of the upper management in wandering in to check at random times. US quality control took a huge jump up in 1943 when some Carnegie Steel executives and QC managers were convicted of manslaughter and sent to jail for a batch of steel that had good paperwork but sent a new ore boat to the bottom of Lake Superior with a broken keel of imitation "steel". SPC is a good tool, but it requires supervision on the part of the factory and the customer. Good product can be turned out in any country, but it requires the "brand" manager to check and keep checking, not fly out to somewhere comfy on Friday night and back Monday AM.
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