Just WHY are DHT tubes SO Expensive....?

[Alastair E]

Considering New Production tubes, Not any original Branded stuff that thas a following...

Valves such as a 2A3 or 300B is made now by a number of makers.....

Looking at their construction In Comparison to something like an EL34, its a relatively simple device, only 1 grid, simple cathode and suspension, basic pressed-tin-box plates not mega tight tolerances needed for assembly etc,...

--Such DHT were developed and made in the 20's-30's when Really fine tolerances of valves were not easily reproducable anyway....

And yet, the likes of 300B are 4 or 5 times the price of a new prod. EL34--For a Cheapo one....

To my mind, a 'complicated' valve such as a Pentode like EL34/EL84 or Heptode frequency-changer that has loads of grids, needing careful alignment and odd beam-forming plates etc 'should' be more expensive--but they aint....

Does this all go back to the 'Cartel' that BVA had in UK where they set the price of valves....?

Or are we all being ripped by valve-makers again!

[dewardh]

"Sucker" products are always overpriced, both in respect to cost of production and what you get from them. But the "official" answer will be "hand made, low production runs, no "economy of scale" to reduce costs. You can believe that if you want . . .

[VictoriaGuy]

Well, I'm sure it doesn't have anything to do with the fact that most customers are in the 'audiophile' hobby......

[bear]

Actually, it doesn't have much to do with any of this...

Consider how a DHT is made first. How is that different from indirectly heated tubes?
What is the difference in materials? How does a directly heated cathode work, how is it made?

What are the sources of materials?

Making these tubes, what are the yields like?
What sort of manufacturing problems and difficulties do you have?

How many tubes of the 2A3 and 300B types made in a year?
How does that compare to the EL34/6CA7 and 6L6 types?

From a business point of view, how many tubes does a small manufacturer of DHTs have to make and SELL in a year to survive - even in China or Eastern Europe??

Now, after figuring all this out, you have ur answer??

_-_-bear

[Wavebourn]

Any production today is costly, because price of dollar, especially in USA, is very low. It is called Inflation. That's why it is more profitable to build simpler production and heat up demand on it. More modern tubes still exist in old stocks, and their clones are in production in countries where the same Dollar is still more expensive.

Also, popular DHT tubes were designed when negative feedback was not applied yet, and cost of manufacturing of tubes was higher, so they were more valuable, that's why they were designed to be more linear than more efficient.

So, people who go for No-NFB fashion have to pay for DHT tubes designed in early years of tube manufacturing.

[andyjevans]

The term DHT covers more than output tubes - it also covers small triodes like 26, 46, 01A and so on which are still reasonably priced on ebay and from some dealers. If you are interested in DHTs don't ignore these - they are superb.

Frankly it doesn't much matter how many new DHTs are made - there's plenty of old stock still and however wonderful they are they're hardly widely used.

andy

[Eli Duttman]

Andy,

The #46 can serve as a driver or as a Class "B2" O/P tube. FWIW, I plan on building an "El Cheapo" variant with #46 "finals". Now to find the money. I already have the 4X #46 tubes.

[Ty_Bower]

Originally Posted by bear

How many tubes of the 2A3 and 300B types made in a year?
How does that compare to the EL34/6CA7 and 6L6 types?

It's that concept, in combination with supply and demand. I'd imagine there is still quite a business manufacturing the EL34 and 6L6 types for the musical instrument (guitar amp) market. Who's buying the 2A3 and 300B? Only the audiophiles. If they're willing to pay, the manufacturers will be more than happy to charge what they can. It's just simple economics at work.

[kevinkr]

Originally Posted by Ty_Bower

<snip> Who's buying the 2A3 and 300B? Only the audiophiles. If they're willing to pay, the manufacturers will be more than happy to charge what they can. It's just simple economics at work.

Precisely, and we all know what happens if the manufacturers cannot charge enough to make it worth their while..

FWIW I have a quartet of JJ 300B, and all have over 5K hours of use on them and have been completely reliable and continue to perform as well as when I bought them ten years ago. I can't say that about any of the cheaper beam tubes I use elsewhere - all have been replaced several times in the same period of time. (Of course I can't say that current JJ 300B production would be as good as a lot of water has gone under the bridge.)

[andyjevans]

At least you don't have to bother with heater-cathode breakdown! I junked a bunch of 807 which were awful for that, but still tested good for emission.

Andy