I asked an open question based on both anecdotal comments and the design expertise of Thomas Mayer, a very respected engineer and tube designer. I got some serious and informative answers from guys like 45, oldHector and 6a3sUMMER, which is what I would expect from serious engineers of their status. I also got some trivial, uninformative and irrelevant comments from others, which unfortunately is exactly what I also would have expected.
Aspects of geometry came up. This seems to be the big aspect here, as the cathode is a "single string" arranged in the center of grid and anode, making the arrangement concentric.
I haven't found images of the mentioned 6SN7 with round plates. It is an indirectly heated triode, so the cathode is concentric with the plate. What about the grid? Is it a round spiral like in Eimacs?
He also said that his ''new'' tube types were no good to use for any other designs besides his built to order boutique amps. So you don't have to worry about the specs or an engineering discussion that includes data comparisons to ''old'' tube types. The market language was all he could offer, so you still have nothing usefull to base an educated decision on even to consider buying his amp offerings. Your original question was legit even if destined to get nothing more than enecdotal and/or pure guesswork replies. This thread could expand to 1000 replies and your gonna get nothing that rises to your satisfaction, I'll wager. Any tube engineers in the audience? If you are, please reply with exceptional linearity.
Simply trust your ears. You know how good the 76, 6G6 etc. are.....
Often detractors have never had one in hand or made comparisons and then you see what they do and what use and it's even more clear....
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Nope. He never said that. He said that they will not be commercially available because they are only used in his amps. That is understandable and obvious given the high costs and investments involved in producing a lot more tubes with the same standards. The same applies to other tube manufacturers like EML and KR, who actually have a bigger market, when they make limited special editions. They will make more if and only if there are substantial orders.
You can call them boutique amps but the fact is that you have negative attitude only because you will never have one. Your comments can be described as anecdotal, guesswork too. You actually are so negatively biased that don't even read carefully and understood what he wrote.
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Not true - we've had good and detailed answers from OldHector and 6a3sUMMER directly addressing the question of how to create equidistant relationships between cathode, grid and anode. That was the point Thomas Mayer was making about a cylindrical structure allowing for perfect symmetry. The complication, as they stated, is how to wind the grid in such a way as to be completely round. As they pointed out, it's easier to wind the grid round the posts connected to the anode structure within a wide rectangular plate. I'm no tube guru but I can see the construction challenges here. It's an interesting subject. Thomas Mayer has been dissecting the internals of commercial tubes for years and years, with loads of photos on his Vinylsavor blog. He knows tube design very well. He now makes expensive boutique amps, but he's more than paid his dues over the years and there's no way it's "snake oil". Have you looked at all the engineering that goes into the interior of his amps? They're stuffed full of Lundahl transformers. No cheap tricks there at all.
Well, Mr. Anonymous says...
''These tubes are meant for use in the Intrepid amplifiers. Since they do not have any equivalent no other amplifier exists that could use them. So it makes no sense to offer them separately. ''....
Seems to imply no one gets to design a circuit for themselves to use the wonder tubes. With all the investment you'd think they'd be offered to all those interested so the investment would pay off economies of scale. I guess these are built to order, too. One at a time with a custom order to the tube factory. The buyer will pay all the production cost up front. No investment risk to lose. Buy a dream, a pretty picture.
''These tubes are meant for use in the Intrepid amplifiers. Since they do not have any equivalent no other amplifier exists that could use them. So it makes no sense to offer them separately. ''....
Seems to imply no one gets to design a circuit for themselves to use the wonder tubes. With all the investment you'd think they'd be offered to all those interested so the investment would pay off economies of scale. I guess these are built to order, too. One at a time with a custom order to the tube factory. The buyer will pay all the production cost up front. No investment risk to lose. Buy a dream, a pretty picture.
There are no other amp manufacturers using them so it does not make any sense to produce more. When some tube amp manufacturer will go and make substantial order you will see there will be more. For small tube manufacturers that's the way it works. I say that dreamers are only those who cannot afford it.
It simply implies that are not generally good for tube rolling and probably also pin-to-pin compatibility. The former alone is already enough.
It simply implies that are not generally good for tube rolling and probably also pin-to-pin compatibility. The former alone is already enough.
You should listen to the 6L6 (yes, metal) SE amp I have running as I write this, I built, and look at the inside. You'd be amazed.
20to20 - It looks like you have no knowledge of Thomas Mayer or his audio history and current projects. In the earlier part of his career he was a huge help to tube builders with his blog and also, let's not forget, his pioneering use of filament bias for DHTs which has been taken up by numerous tube builders since, and has now become standard practice. in his more recent career he has become a tube designer and manufacturer and a designer and vendor of very up market gear. It's at the top end of the market because his amps are full of expensive Lundahl transformers. He's quite an innovator and has a very solid support list of likes from well-known audio engineers on his Facebook page. Trying to trivialise his life's work with comments like "wonder tubes" is pretty uninformed and tacky.
Wow, not planning for tube failures, or runnouts... The order placed could be for 3 at a time. Two free to go with each amp so when needed, you got 'em. ...You know, like when the factory is shut or the designer can no longer place an order for repacements to get the amp back up ..... to specs.
This thread is about YOUR question which was premised on the claims of these ''new'' tubes using a tubular plate and the claim of supremacy for that structure so you could equate YOUR favorite tubes apart from all the others as also being superior. You don't need the new tubes to evaluate the ''truth'' for which you seek. The history of all the offerings of all the structures of any type is available to compare and contrast with real data. Good luck is my honest wish to you. You still haven't answered my first question to you. What do you drive your low gain drivers with?
"What do you drive your low gain drivers with?"......
I don't. Simple answer. I use high gain output tubes like the EL12 so I only need a driver stage with a mu of 9 or a little more to make a 2 stage SE amp. So the input of the amp is the output of the DAC. No preamp needed. Volume control in software on my Mac Pro source. I like to innovate from basic design rather than following the generic practice and just using tubes like 300b and 2a3. Moved on from there.
Judging from the variety of replies it's pretty clear that I asked a question of general interest concerning tube construction. This is a tube forum and tube construction is pretty fundamental.
I don't. Simple answer. I use high gain output tubes like the EL12 so I only need a driver stage with a mu of 9 or a little more to make a 2 stage SE amp. So the input of the amp is the output of the DAC. No preamp needed. Volume control in software on my Mac Pro source. I like to innovate from basic design rather than following the generic practice and just using tubes like 300b and 2a3. Moved on from there.
Judging from the variety of replies it's pretty clear that I asked a question of general interest concerning tube construction. This is a tube forum and tube construction is pretty fundamental.
He said that is using them in his amps, he didn't say he has no plan for replacements. You keep talking about a business you don't actually know. So far TM has been pretty successful. Facts speak for him.
The question Andy posited was about whether differences in plate structure are audible.
The fact that Thomas Mayer's new tubes happen to use a round plate and he claims that this contributes to their "exceptional linearity" are simply reference points which Andy included as an example. The question isn't about Mayer's new tubes, it's about tubes in general.
There are certainly other tube types that are exceptionally linear and not all of them have round plates. For example the 10 and the 26 both have flat / rectangular plates. So, obviously, round plates are not a prerequisite to achieving "exceptional linearity". I'm sure there are many other examples. But, as far as I know, there are no versions of the 10 or the 26 that have round plates.
"Sounds better" will always be determined subjectively and in order for an individual to determine that it seems to me that they would need to listen to the the same tube type, some with round plates and others not round, in the same circuit and system. And so preconceived notions aren't involved, they should not know which plate structure they're listening to.
From an objective viewpoint, is there any evidence that the curves of round and non-round plate versions of the same tube type are different? And, if there is a minuscule difference, is it audible? I'm skeptical that tiny differences in linearity can be reliably identified audibly, even if they can be measured.
And how would you know if the difference is the result of plate geometry? Could it just be normal manufacturing variation? Or some other difference in construction? Or perhaps a difference in Gm or emission level between two tubes of the same type?
It's an interesting question but, unless your amp uses tubes that are available in both round and non round plate versions, the answer is not particularly useful from a practical standpoint. If you do have a choice just do some tube rolling and pick your favorite.
I would be shocked if there was some sort of consensus since the answer is subjective. YMMV, as always.
The fact that Thomas Mayer's new tubes happen to use a round plate and he claims that this contributes to their "exceptional linearity" are simply reference points which Andy included as an example. The question isn't about Mayer's new tubes, it's about tubes in general.
There are certainly other tube types that are exceptionally linear and not all of them have round plates. For example the 10 and the 26 both have flat / rectangular plates. So, obviously, round plates are not a prerequisite to achieving "exceptional linearity". I'm sure there are many other examples. But, as far as I know, there are no versions of the 10 or the 26 that have round plates.
"Sounds better" will always be determined subjectively and in order for an individual to determine that it seems to me that they would need to listen to the the same tube type, some with round plates and others not round, in the same circuit and system. And so preconceived notions aren't involved, they should not know which plate structure they're listening to.
From an objective viewpoint, is there any evidence that the curves of round and non-round plate versions of the same tube type are different? And, if there is a minuscule difference, is it audible? I'm skeptical that tiny differences in linearity can be reliably identified audibly, even if they can be measured.
And how would you know if the difference is the result of plate geometry? Could it just be normal manufacturing variation? Or some other difference in construction? Or perhaps a difference in Gm or emission level between two tubes of the same type?
It's an interesting question but, unless your amp uses tubes that are available in both round and non round plate versions, the answer is not particularly useful from a practical standpoint. If you do have a choice just do some tube rolling and pick your favorite.
I would be shocked if there was some sort of consensus since the answer is subjective. YMMV, as always.