Tube Amplifier Reliablity- A Concern?

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JoshK

Re: Tube Amplifier Reliablity- A Concern?
« Reply #20 on: 19 Oct 2008, 04:20 pm »
In general, I won't be bothered to make PCBs, but then again, I've never tried.  However, Broskie uses really thick PCB boards for his Aikido boards.  They were intended to take repeated tube rolling without cracking.  It seems like a good idea if you are going to mount the sockets on PCB that you use a thicker board even if it costs more.

I think I will still wire the heaters directly, even on the Aikido boards.  I think the only reason why the heaters are on the board is convenience, but I'd rather not send higher current through the traces when I can just bring the heater wiring right up the the sockets.

Niteshade

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Re: Tube Amplifier Reliablity- A Concern?
« Reply #21 on: 20 Oct 2008, 11:14 am »
I made them before in college and got a messed up tee shirt as a result. The acid bath must have splashed on me even though I never saw or felt it.  :o

In general, I won't be bothered to make PCBs, but then again, I've never tried.  However, Broskie uses really thick PCB boards for his Aikido boards.  They were intended to take repeated tube rolling without cracking.  It seems like a good idea if you are going to mount the sockets on PCB that you use a thicker board even if it costs more.

I think I will still wire the heaters directly, even on the Aikido boards.  I think the only reason why the heaters are on the board is convenience, but I'd rather not send higher current through the traces when I can just bring the heater wiring right up the the sockets.

Niteshade

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Re: Tube Amplifier Reliablity- A Concern?
« Reply #22 on: 26 Oct 2008, 12:27 pm »
What power and small signal tubes are you getting the most time out of?

Do you think the most reliable tubes are also the best sounding?

JimJ

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Re: Tube Amplifier Reliablity- A Concern?
« Reply #23 on: 26 Oct 2008, 04:26 pm »
Tubes with thoriated tungsten filaments are pretty good for a long service life in my experience.

Reliability and how they sound are independent of each other, IMHO.

Niteshade

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Re: Tube Amplifier Reliablity- A Concern?
« Reply #24 on: 27 Oct 2008, 03:39 pm »
Tubes with thoriated tungsten filaments are pretty good for a long service life in my experience.

Reliability and how they sound are independent of each other, IMHO.


I was looking for any correlation, since a better constructed tube could sound better.  I do like the sound of large triodes, like the 845.

Niteshade

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Re: Tube Amplifier Reliablity- A Concern?
« Reply #25 on: 27 Oct 2008, 03:42 pm »
Tube longevity as it relates to the 6L6 family:

Using a power tube at 50% or less of its rating will make it last longer. Would anybody object to a design that uses, say 4 6L6's to generate 40 to 50 watts instead of using two of them? You would have to buy more tubes, but much less often.  I'd still want the tubes to be hefty and have 30 watt anodes.

JimJ

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Re: Tube Amplifier Reliablity- A Concern?
« Reply #26 on: 27 Oct 2008, 04:12 pm »
Tubes with thoriated tungsten filaments are pretty good for a long service life in my experience.

Reliability and how they sound are independent of each other, IMHO.


I was looking for any correlation, since a better constructed tube could sound better.  I do like the sound of large triodes, like the 845.

There definitely needs to be a basic level of quality...I remember the stock rectifier when I had the Decware Zen was a Chinese 5U4G, the thing had a mechanical buzz like a bug zapper...replaced it with an NOS GE, problem solved. But I'm not sure just because a tube is built really well, means it'll last longer (outside of out-and-out failure)...there could be some really primo signal tubes that are built well but have short lifespans. And there could be some sonic junk out there that'll last for a decade.