Opinion upon amp life expectancy at 5 hours/day? (theres a catch)

[Layberinthius]

What brand are they?

[Layberinthius]

oh electroharmonix

[Frank Berry]

Tubes can last a very, very long time if they are operated within their design specs.

I have a Zenith Console Radio that was manufactured in 1938.
It operates with six of it's original tubes!

[Layberinthius]

mmm I can understand why they are so reliable, in 1938 I bet not too many could pay the power bill long enough to have them on for a few hours a week!

AND of course the makeup of mere metal and solder with a burning wire doesn't exactly allow for very much mechanical failure = if they aren't running hot :P

I intend wholeheartedly to run everything "just" below spec, I'm making a valve amplifier not only for:

1. Looks
2. Sound quality with such a simple design.
3. My KISS methodology to everything.
4. I can brag that my amp has more useful watts. Can I? :P No.
5. Everything in nature and life (reality) has it's own character.
6. Reliability! (I don't have to go to wal-mart/future-bi-lo to get another one in 50 years)
7. Now in the state of the supply of electricity to homes it's more important to me to have something able to handle that extra sudden 60volts and still be alive.
8. I've replaced so much "modern, reliable, tech" bull it's makin me sick and turning me green /me grabs hat and runs off nude
9. If I ever get struck by lightning, I want something that they can sell for a coffin on ebay.com.au. (Probably get $1)
10. I LOVE kick-*** nostalgia from 1930's on :P

Cheers!

[buchignani]

I was seriously into amateur radio in its last tube only days, and my experience about the reliability of tubes is radically different than what has been reported here. Our (then) posh receivers typically had 20-30 tubes in them, and for maximum performance I was replacing one or another every couple of months.

Anyone remember tube-based colour televisions: nightmares re: reliability because of tube deterioration. Norman

[Layberinthius]

mmm yes, but you must remember nearly all early and even late tv's had plenty of high-powered high-voltage components and were /VERY/ heavily manufactured, maybe most manufacturers cut corners and used the most possible out of the humble tube, although I don't see how that could affect valves like in the audio stage or first stage of VHF amps?

Driver tubes I could understand, come on 6+ kV? :P

I can't say anything to calm your 'receiver' woes tho..

hmm A LOT of valves!

Maybe before the days that FM was easy?

Cheers.

[Layberinthius]

Heck it could all be put down to poor design of other components than the tubes that ofcourse /made/ the tubes degrade more often than they should be?

[buchignani]

Sorry, in regard to tube-based colur television reliability I wasn't referring to the picture tube, but to the others.

Anyone around in those days will recall that tube replacement in televisions and radios was so frequently required that customer-run tube testers and tube supplies were even available in supermarkets. Norman

[Layberinthius]

Ehm,

Yes I know tube replacement was often in Tv sets back then, my brother's father told me a few times that tv tubes in tv sets were always being replaced, not to mention I also got my share of old-time american movies where they were replacing valves on tv or having a referral towards them getting replaced..

Maybe this is what threw you off :P

"Driver tubes I could understand, come on 6+ kV? :P"

It is late and I think i'll go :P

also, I'm easy on people, but not when I'm tired, so i'm a bit grouchy. sorry.

[Layberinthius]

And yes, the CRT was hardly ever replaced, half of the time it could be fixed by a simple jolt to one of the guns (not sure of details, but i'm sure any half-witted electro-jocky could tell you that it's still done today)..

Most of the time it was some other component, till this day the CRT is the most reliable component of the TV set!

Although don't mess with them in old sets pre-1980 even.

They're like bombs just moving an old-style tv set is risking your neck! or for better words risking plenty of cuts and maybe even a hand inside a heap of imploded glass fragments, that or a discharge from the set circut itself that could blow you straight flat on your back over a varandah or something :P

I remember reading an old 1970's tv repair manual that I still have handy somewhere, In a 'Saftey' portion of the book front-and centre it had the picture of a nice 1950's set with a whole heap of fragments all over the floor up to 12 foot from the set!!

Cheers.