Good tube experience

[FrantzM]

Myles

I will have to drop out of the discussion after this. I don't use tube in my system and haven' for more than 10 years ... I di hoever think that in these days of cheap and available computing power it should be fairly easy, if there is a profit potential to replicate the great tubes of yore. I do also understand that some of these tubes would not be only cosmetically similar to the original. Replication sholudn't be difficult for the determined. Much more complicated items have been replicated and in many ways bettered.
The point I am trying to make is that of objective parameters. There are such for tubes and I would think that tubes which measure the same do sound the same ..else how were they made in the first place?
I apologize for this Cartesian bent that refuses to accept magic in the making of a technological item. and will retreat to my SS oasis awaiting your reply.

 

[MylesBAstor]

Myles

I will have to drop out of the discussion after this. I don't use tube in my system and haven' for more than 10 years ... I di hoever think that in these days of cheap and available computing power it should be fairly easy, if there is a profit potential to replicate the great tubes of yore. I do also understand that some of these tubes would not be only cosmetically similar to the original. Replication sholudn't be difficult for the determined. Much more complicated items have been replicated and in many ways bettered.
The point I am trying to make is that of objective parameters. There are such for tubes and I would think that tubes which measure the same do sound the same ..else how were they made in the first place?
I apologize for this Cartesian bent that refuses to accept magic in the making of a technological item. and will retreat to my SS oasis awaiting your reply.

Yes at first blush it would seem easy to duplicate the tubes of yore But the real world experience is that these efforts have been a mixed success

One problem as pointed out by tube guru Tim de Paravicini is that certain types of metals (I seem to recall him saying there was a Fe /Su?) used back then don't exist any more. Also Tim seemed to feel that present day equipment (and I don't know though it seems that could ) doesn't draw as good a vacuum as the manufacturers did back in the '50s and '60s.

I think a while back I posted a note from someone in the Pro recording arena well known for building mikes actually documenting the differences between NOS and new tubes and say filament coatings etc. Another problem this person pointed out is that the Russians just don't care And unfortunately the Chinese tubes I've heard are nothing to write home about.

And believe it or not, there are times in the past year or two (similar to Mark's reports) where I really appreciated the sound and esp. quietness of a really well designed solid-state phono stage like the Avid Pulsare. In fact, just leant my Avid to a close audiobuddy who is a die hard tubeaholic who was having problems with his Fosgate phono stage and even he was very impressed. In fact, he even said, he could live with the phono stage. Now that's high praise coming from him

 

[FrantzM]

Myles

Last post on the subject. I will leave it you guys to your tubes preoccupitions

Last I heard all the stable elements of the periodic table are still accounted for ..some more bountiful than others but none expensive enough not to be unable to found their ways into an item a group of people would be wiling to pay more than $1,000 for.. These tubes in all likelihood do not contain Kg of those aptly named rare elements ...
And again it seems logical to me that to make these things, the manufacturers had to measure, weigh or follow some kind of formula, you know a method, a repeatable one .. It is technological matter after all.. not conjuring some some magic .. These technological can be replicated or reverse engineered ...

But if some of us, audiophiles want to think that their provenance from given locales make is a sign that these have to be inferior then ... no set of numbers will ever be enough to change their opinion ...

I am out, done hijacking your threads, I apologize ...

 

[microstrip]

This is news to me as I have never heard of this before. Using Telefunken's logo in the production of another branded tube during the day when Telefunken tubes were actually in production seems like would have caused serious issues with Telefunken. Companies usually safeguard/legally defend the use of their logo in another company's products. Trademark infringement I believe it is called. Looking for the diamond embossed in the bottom of the glass was pretty much your only assurance that you were buying a true Telefunken tube. If what you say is true, everyone is basically screwed. You talk about measuring pin diameter. How many people have a pair of dial calipers and know how to use them?? What is the diameter of a true Telefunken pin and the diamater of the pins used on tubes which have the Telefunken logo embossed on the bottom?

Mep,
My friend learn it by the expensive way - btw in a Jadis JPL preamplifier. He called me to listen to a change in his system, but did not tell me what it was. Upon arrival I noticed that the sound was edgy and lacked the characteristic lush sound of his system, but I could see no change in the system .
The only thing we noticed when we measured the tubes in a tester was a small imbalance between triodes - nothing that could explain the bad sound of his fake TFK 12AX7s. It is not easy to measure the pins diameter accurately - I have a caliper with 1 micron accuracy but I would have to cut the pin ...

The tubes had the diamond, but the lettering was firm and clear - it did not pass the nail test.

 

[microstrip]

For the returns on investment involved.. The acquisition of a micrometer caliper would seem to be trivial for a would-be scammer. A good one can be had for less than $500. Aren't there objective parameters for these tubes? Not that I am in tubes but there has to be some ways to measure an ascertain what tubes one is using or at least I would think so...

As usually, identification of fakes depends on your skills and knowledge. But it takes time and a lot of work to gain expertise - happily my gear uses the 6H30 ...
The only possible parameter would be based in the analysis of tube microphony - some thing difficult to measure with reliability in a repeatable way - I think that the micro-vibrations of tube are one of the possible sources of good and bad "tube sound".

 

[microstrip]

Myles

Last post on the subject. I will leave it you guys to your tubes preoccupitions

Last I heard all the stable elements of the periodic table are still accounted for ..some more bountiful than others but none expensive enough not to be unable to found their ways into an item a group of people would be wiling to pay more than $1,000 for.. These tubes in all likelihood do not contain Kg of those aptly named rare elements ...
And again it seems logical to me that to make these things, the manufacturers had to measure, weigh or follow some kind of formula, you know a method, a repeatable one .. It is technological matter after all.. not conjuring some some magic .. These technological can be replicated or reverse engineered ...

But if some of us, audiophiles want to think that their provenance from given locales make is a sign that these have to be inferior then ... no set of numbers will ever be enough to change their opinion ...

I am out, done hijacking your threads, I apologize ...

Frantz,

As you were correctly referring tube duplication is an engineering problem - if you invest lots of money and resources probably you would make them. But it is a small market and you would not recover your investment.

People have spent their lives trying to duplicate a Stradivarius - I have seen PhD thesis in material's engineering on this subject and they did not manage it. The materials of the tube electrodes should be critical both from the electrostatic point and the mechanical one - remember all these fragile and thin mechanical inner structures have surface imperfections.

 

[MylesBAstor]

This is the thread I was referring to:

http://recforums.prosoundweb.com/index.php/mv/msg/16812/238372/0/#msg_238372

This is the particular post:





Oliver Archut
Messages: 1128
Registered: April 2004


Platinum Member





Hello Paul,
Over the last 10 years I talked numerous times with Mike, JC and even Irushka in Russi

There are two big factors with Russian tube manufactures why their tubes never can live up to old Western specimens:

the production steps they CAN NOT DO and the production steps they DO NOT WANT TO DO. Aside of that, the raw material' situation is quite poor and even tough I supplied Mike and JC with the companies' names which still make some of the material they needed, nothing happened so far.

The problems in detail:

One of the biggest problem with Russian tubes is the cathode/filament and then 2nd is the chemical procedure that applies the active coating to them.

The noise Klaus talks about is a barium coating that gets deposited onto the first grid after about 200h. This makes those tube too noisy even for simple applications with a 3 Meg Ohm grid leak; using a gold plated first grid won't help that problem- in fact it makes it even worse.

The 2nd problem is the isolation coating of the filament that deposits small traces of magnesium onto the entire tube electrodes.
When disassembling a used tube you can see those problems for yourself just by holding the grid(s) into a flame and seeing how the color turns greenish. A new tube that you take apart and subject to the same test won't show those colors)

I am still hoping that the remaining tube factories will notch up the quality so that those new tubes are useable in studio gear... But I do not see that it has happened so far.

Regarding Mike's 300B tube: it is as good or bad as the newly produced 300B that just licensed the historic WE name...

Still using their (Russian-made) standard EL84s for my Oahu's...

Best regards,


--------------------------------------------------------------------------------
Oliver Archut
www.tab-funkenwerk.com

We are so advanced, that we can develop technology that can determine how much damage the earth has taken from the development of that technology.

Now things may have changes a bit since this post but don't think so

 

[MylesBAstor]

Myles

Last post on the subject. I will leave it you guys to your tubes preoccupitions

Last I heard all the stable elements of the periodic table are still accounted for ..some more bountiful than others but none expensive enough not to be unable to found their ways into an item a group of people would be wiling to pay more than $1,000 for.. These tubes in all likelihood do not contain Kg of those aptly named rare elements ...
And again it seems logical to me that to make these things, the manufacturers had to measure, weigh or follow some kind of formula, you know a method, a repeatable one .. It is technological matter after all.. not conjuring some some magic .. These technological can be replicated or reverse engineered ...

But if some of us, audiophiles want to think that their provenance from given locales make is a sign that these have to be inferior then ... no set of numbers will ever be enough to change their opinion ...

I am out, done hijacking your threads, I apologize ...

Don't forget the environmental laws say in the common market that put co's such as Lyra Connoisseur out of the market.

LYRA CONNOISSEUR 4-2L SE Line Preamplifier
Not available. Production has been discontinued since 2007 because new European ROHS rules outlawing certain substances in all electronic parts and products sold in the EU caused many parts manufacturers to discontinue critical parts used in the Lyra Connoisseur preamplifiers. Even though the ROHS laws only concern the EU, the worldwide discontinuation of critical parts, which were never replaced by ROHS-approved equivalents, caused that LYRA was forced to stop production of the Lyra Connoisseur preamplifiers alltogether. Full service & support available. Also, on a case by case basis we are able to upgrade older 4-series versions to 4-2 SE level.
LYRA's Connoisseur 4-2L SE preamplifier raises the state of the art in the reproduction of recorded music.

Even though it appears simple and elegant, the 4-2L SE is an extremely complex and intricate construction based around two separate amplifier modules with all critical nodes built as "air dielectric", 12 separate regulators per channel all with discrete components only.

Air-dielectric circuits are fabricated by an exceptionally skilled craftsman who trained originally as a cartridge builder. The Connoisseur 4-2 is too delicate and too complex to be made by normal electronic technicians, or by machine. A custom coaxial switch switches between separate metal foil resistors in a "make-before-break" arrangement on two separate decks - one per channel, while the rearmost deck of the switch takes care of input selection.

The remote power supply is extremely robust, starting with one 190VA transformer per channel, followed by substantial primary power supply filtering of 10,000 uF x 2 per channel. The interior of the main chassis being assisted by comprehensive local power supply bypassing, as well as multiple regulation of the amplifier modules.

 

[FrantzM]

Hi

Forced to reply...

Tubes are technological constructs. They are fabricated following in most cases written, well documented processes. Tubes are not made with some kind of Coca-Cola formula known only to a few. There could be patent covering some tubes but I am willing to bet that many of these patents have expired and/or are being replicated by some industrious and adventurous individuals or companies.
I can understand that some companies find the process too tedious or costly to follow to the letter and this may produce subpar tubes... If they cut corner on material and manufactures then performance will suffer. Dishonest manufacturers dishonest may try to sell bad tubes as good especially when they look alike. It doesn’t help that most tube-loving don’t have anything to test the tubes with or worse don’t believe in measurements only in their ears or some gurus that would validate their purchases. The companies who bought the old RCA or GE tubes manufacturing plants certainly insisted in having the processes and patents too , I would think… While the electrical characteristics of tubes do vary (Same with SS) these variations are within known ranges.. A given manufacturing process produces tubes that fall within that range if it weren’t the case there would be no way of replacing a tube with another tube of the same model … I am NOT sure one starts the process to make an 12AX7 and ends up with the characteristics of an EL 34 !!!
When it comes to Strad and Guarneri .. I haven’t heard that their fabrication, process and material list were documented. If these were than they would be replicated… unless we want to believe that Guarneri and/or Stradivarius had to conjure some spirits in the making of their wares … if they documented their incantations ... then …

 

[mep]

Frantz-As someone who is involved with the microwave tube industry, I’m here to tell you that tube manufacturers *lose* their own recipe sometimes and can’t make tubes that pass the contractual specifications. And when I say they *lose* the recipe, what I mean by that is that something has changed in their production process and the tubes are no longer worth a damn. The usual culprit is one of two things: they have lost one or more of their key production personnel or they have switched vendors for critical parts.

Now let me give you another example. When WE decided to put the 300B back into production, they had one hell of a time even though they had all drawings, parts lists, and specifications/procedures on how to build the tube including how to dope the cathode. They had the original machines the tubes were made on as well. This should have been a cake walk right? It wasn’t. There are always things that are done by production personnel that are never written in any procedure and those little tips/tricks/steps they perform can be and usually are the difference between making a good tube vs. making junk.

With regards to tearing a tube apart and reverse engineering it, it’s easier said than done. Figuring out the cathode composition and the doping procedure is no trivial task.

 

[Phelonious Ponk]

I once bought a pair of NOS Visseaux 6v6 tubes for a 1965 Fender Deluxe Reverb I owned. I bought them mostly because they had a reputation for clipping slower and smoother than most 6v6 tubes, and a Deluxe is a rather smallish amp to gig with, so a bit more headroom before breaking up into glorious crunch was useful. I must confess I was also drawn to the fact that they were manufactured in the year I was born -- 1951. They worked as advertised, but tubes are not forever, and many gigs later they needed to be replaced. I replaced them with a matched pair from one of several US and European companies who imported many tubes from Russia and China, carefully tested them and matched them in pairs and quads, threw away more than they kept, then sold the sets to guitar players, a picky lot that are every bit as OCD as Audiophiles. I confess that, while they were all good, I went through three pairs before I found a set that responded exactly like the Visseauxs, though I still spent a lot less money.

The moral to the story? It wasn't magic spells trapped in the vacuum of valves or serendipity on the production line that made the old ones better; it was much more mundane than that. It was quality control. The market for vacuum tubes is so small that top-quality companies in first world countries, companies like GE, Visseaux and Telefunken, don't care to support the technology anymore. The factories in China and Russia turn out a lot of crap, or at least they used to. But $1000 - $1300 for a single preamp tube? Good Lord. I could set up a company throwing away 90% of the Chinese tubes imported, to find the roses among the thorns that would meet if not exceed the tubes of old, and sell them for a fraction of that.

But Audiophiles wouldn't buy them. They want to buy magic, not QC.

Tim

 

[microstrip]

Hi

Forced to reply...

Tubes are technological constructs. They are fabricated following in most cases written, well documented processes. Tubes are not made with some kind of Coca-Cola formula known only to a few. There could be patent covering some tubes but I am willing to bet that many of these patents have expired and/or are being replicated by some industrious and adventurous individuals or companies.
I can understand that some companies find the process too tedious or costly to follow to the letter and this may produce subpar tubes... If they cut corner on material and manufactures then performance will suffer. Dishonest manufacturers dishonest may try to sell bad tubes as good especially when they look alike. It doesn’t help that most tube-loving don’t have anything to test the tubes with or worse don’t believe in measurements only in their ears or some gurus that would validate their purchases. The companies who bought the old RCA or GE tubes manufacturing plants certainly insisted in having the processes and patents too , I would think… While the electrical characteristics of tubes do vary (Same with SS) these variations are within known ranges.. A given manufacturing process produces tubes that fall within that range if it weren’t the case there would be no way of replacing a tube with another tube of the same model … I am NOT sure one starts the process to make an 12AX7 and ends up with the characteristics of an EL 34 !!!
When it comes to Strad and Guarneri .. I haven’t heard that their fabrication, process and material list were documented. If these were than they would be replicated… unless we want to believe that Guarneri and/or Stradivarius had to conjure some spirits in the making of their wares … if they documented their incantations ... then …

Most of the time the manufacturing documentation does not exist anymore, or it is not accessible and most of it, the human experience is lost. All of this will cost a lot to recover. I have not said impossible, I said too expensive.

If you read the literature published after the second world about reliability of tubes you will find amazing facts about tube manufacture - I am sure that if someone sees the tube production lines in factories and how tubes were made he will immediately understand why it is not possible to start manufacturing TFK tubes tomorrow. It is not just changing the command programs of the factory robots. The people who bought the tube plants (chinese, as far as I know) have a video of their new facilities, unhappily I could not find it this time, and I do not have easy access to the photos I saw in the old issues of Wireless World form the 50s and 60s.

I used the Stradivari argument just to show that reverse engineering can not solve everything.

BTW, a 12AX7 (triode) can not end with the characteristic of an EL34 (pentode) - it misses some electrodes

 

[microstrip]

I once bought a pair of NOS Visseaux 6v6 tubes for a 1965 Fender Deluxe Reverb I owned. I bought them mostly because they had a reputation for clipping slower and smoother than most 6v6 tubes, and a Deluxe is a rather smallish amp to gig with, so a bit more headroom before breaking up into glorious crunch was useful. I must confess I was also drawn to the fact that they were manufactured in the year I was born -- 1951. They worked as advertised, but tubes are not forever, and many gigs later they needed to be replaced. I replaced them with a matched pair from one of several US and European companies who imported many tubes from Russia and China, carefully tested them and matched them in pairs and quads, threw away more than they kept, then sold the sets to guitar players, a picky lot that are every bit as OCD as Audiophiles. I confess that, while they were all good, I went through three pairs before I found a set that responded exactly like the Visseauxs, though I still spent a lot less money.

The moral to the story? It wasn't magic spells trapped in the vacuum of valves or serendipity on the production line that made the old ones better; it was much more mundane than that. It was quality control. The market for vacuum tubes is so small that top-quality companies in first world countries, companies like GE, Visseaux and Telefunken, don't care to support the technology anymore. The factories in China and Russia turn out a lot of crap, or at least they used to. But $1000 - $1300 for a single preamp tube? Good Lord. I could set up a company throwing away 90% of the Chinese tubes imported, to find the roses among the thorns that would meet if not exceed the tubes of old, and sell them for a fraction of that.

But Audiophiles wouldn't buy them. They want to buy magic, not QC.

Tim

Tim,

You are extrapolating from a well known and described effect (soft clipping due to the tube curves) to something that is completely different (tube sound characteristics in normal linear operations). From it you arrive to false conclusions involving QC and end in some considerations about audiophile magic. Happily Audiophiles from WBF wouldn't buy them - they want good sound. Getting good sounding tubes is not just a selection post- process at the end of the line.

 

[MylesBAstor]

Most of the time the manufacturing documentation does not exist anymore, or it is not accessible and most of it, the human experience is lost. All of this will cost a lot to recover. I have not said impossible, I said too expensive.

If you read the literature published after the second world about reliability of tubes you will find amazing facts about tube manufacture - I am sure that if someone sees the tube production lines in factories and how tubes were made he will immediately understand why it is not possible to start manufacturing TFK tubes tomorrow. It is not just changing the command programs of the factory robots. The people who bought the tube plants (chinese, as far as I know) have a video of their new facilities, unhappily I could not find it this time, and I do not have easy access to the photos I saw in the old issues of Wireless World form the 50s and 60s.

I used the Stradivari argument just to show that reverse engineering can not solve everything.

BTW, a 12AX7 (triode) can not end with the characteristic of an EL34 (pentode) - it misses some electrodes

Drool....

http://mullardtubes.com/Video.aspx

 

[Phelonious Ponk]

Most of the time the manufacturing documentation does not exist anymore, or it is not accessible and most of it, the human experience is lost. All of this will cost a lot to recover. I have not said impossible, I said too expensive.

If you read the literature published after the second world about reliability of tubes you will find amazing facts about tube manufacture - I am sure that if someone sees the tube production lines in factories and how tubes were made he will immediately understand why it is not possible to start manufacturing TFK tubes tomorrow. It is not just changing the command programs of the factory robots. The people who bought the tube plants (chinese, as far as I know) have a video of their new facilities, unhappily I could not find it this time, and I do not have easy access to the photos I saw in the old issues of Wireless World form the 50s and 60s.

I used the Stradivari argument just to show that reverse engineering can not solve everything.

BTW, a 12AX7 (triode) can not end with the characteristic of an EL34 (pentode) - it misses some electrodes

Nah, it wasn't really all that serious, micro. I know there is a difference between knowing the subtle clipping dynamics of a tube with your hands and ears and understanding how that same tube behaves within its normal operating range. I was telling a story of quality control, to offer a demonstration of the real difference between quality vintage NOS tubes and modern ones.

Tim

 

[MylesBAstor]

I once bought a pair of NOS Visseaux 6v6 tubes for a 1965 Fender Deluxe Reverb I owned. I bought them mostly because they had a reputation for clipping slower and smoother than most 6v6 tubes, and a Deluxe is a rather smallish amp to gig with, so a bit more headroom before breaking up into glorious crunch was useful. I must confess I was also drawn to the fact that they were manufactured in the year I was born -- 1951. They worked as advertised, but tubes are not forever, and many gigs later they needed to be replaced. I replaced them with a matched pair from one of several US and European companies who imported many tubes from Russia and China, carefully tested them and matched them in pairs and quads, threw away more than they kept, then sold the sets to guitar players, a picky lot that are every bit as OCD as Audiophiles. I confess that, while they were all good, I went through three pairs before I found a set that responded exactly like the Visseauxs, though I still spent a lot less money.

The moral to the story? It wasn't magic spells trapped in the vacuum of valves or serendipity on the production line that made the old ones better; it was much more mundane than that. It was quality control. The market for vacuum tubes is so small that top-quality companies in first world countries, companies like GE, Visseaux and Telefunken, don't care to support the technology anymore. The factories in China and Russia turn out a lot of crap, or at least they used to. But $1000 - $1300 for a single preamp tube? Good Lord. I could set up a company throwing away 90% of the Chinese tubes imported, to find the roses among the thorns that would meet if not exceed the tubes of old, and sell them for a fraction of that.

But Audiophiles wouldn't buy them. They want to buy magic, not QC.

Tim

Except that TFK claimed 10^4 hours of service from their tubes under normal operating conditions. Don't think that overdriving the tubes counts as normal conditions.

 

[Phelonious Ponk]

Except that TFK claimed 10^4 hours of service from their tubes under normal operating conditions. Don't think that overdriving the tubes counts as normal conditions.

It does to guitar players. We're a bit harder on tubes than audiophiles. We're also intimately, organically familiar with the way those tubes respond under all kinds of conditions, overdriven and otherwise. Apples and oranges? Perhaps. The point remains the same; the magic in NOS tubes in QC. Basic QC, and a much higher level of consistency. I might have to throw a lot away, but I'd still guess someone could find a Svetlana that would perform with a vintage TFK. And I'll bet I'd come in way under the cost of the TFK. There is another solution. It was found and executed successfully for a market that wouldn't spend a grand for a preamp tube.

Tim

 

[microstrip]

(...) The point remains the same; the magic in NOS tubes in QC. Basic QC, and a much higher level of consistency. I might have to throw a lot away, but I'd still guess someone could find a Svetlana that would perform with a vintage TFK. And I'll bet I'd come in way under the cost of the TFK. (...)
Tim

If you look at the structural differences between these two brands of tubes (e.g. for the 12AX7 type ) you will see that this is not possible. Although they share similar basic minimum curves - it is why they are of the same type - they are just similar. The electrodes active area, geometry and distances, not to speak about the mechanical properties are different. Do you think that the short datasheet with three basic parameters at fixed conditions, maximum ratings and typical curves completely describes the tube? It is like buying new tires for your car just by the standard code numbers on them.

Should we consider that in the limit one in a million of poor 12AT7s will have the performance of a 12AX7? Both have cathode, grid and plate.

 

[Phelonious Ponk]

If you look at the structural differences between these two brands of tubes (e.g. for the 12AX7 type ) you will see that this is not possible. Although they share similar basic minimum curves - it is why they are of the same type - they are just similar. The electrodes active area, geometry and distances, not to speak about the mechanical properties are different. Do you think that the short datasheet with three basic parameters at fixed conditions, maximum ratings and typical curves completely describes the tube? It is like buying new tires for your car just by the standard code numbers on them.

Should we consider that in the limit one in a million of poor 12AT7s will have the performance of a 12AX7? Both have cathode, grid and plate.

Who said anything about 12AT7s? I was talking about 6v6s, radically different from any of the 12A tubes. Power tubes, not preamp tubes. But 12Ax7s are common in guitar amplifiers as well, and are included in the products of the companies I spoke of that import Russian and Chinese tubes, run QC on them, then sell the ones that pass. Guitar amps and hifi are very different beasts, though, maybe they would never find enough that would make the cut. Hard to say...

At any rate, go back to your conversation. This thread isn't about guitar amps, I just thought it was a story that illustrated that the problem is probably QC and has, in fact, been successfully addressed as such in another market.

Tim

 

[MylesBAstor]

I might have to throw a lot away, but I'd still guess someone could find a Svetlana that would perform with a vintage TFK. And I'll bet I'd come in way under the cost of the TFK. There is another solution. It was found and executed successfully for a market that wouldn't spend a grand for a preamp tube.

Tim

Not in this dimension.