MK-U47 - build thread

I also updated the first post with more pics.

Moby said:

ioaudio said:

Moby,

actually the transformer i sent you in 2008 was made from original laminations Garantie a-52 made by VAC in the 70-ies.
So what you analysed was a product made by Vacuumschmelze Hanau, not my own.

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Of course, I analyzed Garantie A-52 (Sourced from Belgium gentleman) winded by you,  and few more original Neumann's (not yours) lams including the early (less nickel) and later (more nickel) BV8's. Of course there is the very first "very low nickel" laminate used in the first U47 but that's another story because it's not UI30 But if you are curious, there is just a slight difference between those and 50's "low nickel" . I don't use "garantie 50,51,52" def's because it's connected just to one manufacturer of the UI30 lamination. Besides VAC U know that Krupp also made these but there is one more manufacturer in that game, actually complete manufacturing went to USSR after the 2. WW. Unfortunately they never stamped UI30's but it's still possible to buy sheets in that thickness and with same chemistry but in large quantities. They also look like VAC's (they are not black anodized) U know that yellowish shine )) MAX, again, I don't want make any confusion or to share some suspicious minds . I just share my knowledge to the people here in the community. Don't take it personally.
Also, as far I know A52 was never used by Neumann. On the other hand I don't have any problem with it because is soooo, similar to later "H nickel" chemistry. To be precise it contains 2% less Nickel exchanged for Molybdenum because they "improved" that way earlier A51.

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Very interested in this discussion, may I ask the exact chemistry of A50, A51 and A52? And how this chemical difference impact on the magnetical and electrical result of the core?

Fra

Just take a listen the sound examples at Cinemag site where you can compare old with new alloy directly.

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Yep. I was some time ago I listened to those samples, but I do remember the very obvious difference. I also remember being amazed that apparently some seemed to think they sounded very similar indeed. Well, some may have been biased, of course.
Not to put down Cinemag BTW. They make great trannies.

Sorry I can't post the complete chemistry since it's never been published and I really don't know the consequences of making it public.

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Right now, I can't think of anyone who would not benefit, except maybe yourself. (?)

I made all the analyses to learn something or maybe to make old soft magnetics alloy available to the DIY community.

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So exactly in what way will it become available to the DIY community then?
Seriously interested.

edit

Wow, this looks like modern art.

And the upper right and middle left could be abalone shells.

And the yellow MOP completes the magenta and cyan, for those who are into photography.

And what about the shades of grey, for those ......... um, never mind.

Useless post. Sorry. Just had to share. 

Anyway, do keep this stuff coming!

So from what I can understand searching the net, all the three A50, A51 and A52 should have Ni 50% content and Mo content from 3.5% to 4% and Fe to balance. This will tell that the only difference in the alloy mixture is in the Mo and Fe content, but from what Max is saying the Mo content give different response in the heat annealing treatment, and from what I can understand searching the net Vacuumschmelze and Krupp had different approach in this treatment, so how is possible that Neumann used all the two supplier over the time without having to change their transformer?

Fra

Moby said:

BraFra said:

So from what I can understand searching the net, all the three A50, A51 and A52 should have Ni 50% content and Mo content from 3.5% to 4% and Fe to balance. This will tell that the only difference in the alloy mixture is in the Mo and Fe content, but from what Max is saying the Mo content give different response in the heat annealing treatment, and from what I can understand searching the net Vacuumschmelze and Krupp had different approach in this treatment, so how is possible that Neumann used all the two supplier over the time without having to change their transformer?

Fra

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Nope. Not even close to true chemistry. Don't try to google about it it will just mislead you . There is a lot false infos on the net regarding this types of  alloys. BTW,  alloys used in the first era of U47 up to 1953. is very different to later (one I tested was from 1958) Let's say that later is more complex , and of course with better permeability.

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For having the information about the 50% nickel content I have contacted two of the main manufacturer that proclaims to build correct replicas, so there are two possibility or their replicas are not so correct or they want to keep their secret
Anyhow could you tell me where I can get correct information without having false infos?

Fra

Moby said:

I'm afraid that chemical composition is trade secret together with annealing process. It's up to you to listen, compare and finally decide.

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I'm still in a mist here. Nothing wrong with secrets, but exactly who "owns" this 60-odd year old knowledge?

possible consequences with present  Bv.8 replica manufacturers. There is one of them doing it  close enough to original and I think he will be really pissed of if I just put that info in the ear .

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This person X doing it close enough to original according to you, suggests you know at least as much as he does (more in fact). So why wouldn't you be free to share this? Surely anyone who's capable can do his own analyzing and research. But does this mean that the first one who puts something resembling the old product in the market automatically gets protection and others can no longer talk about the details? Or is there such a thing as patent re-incarnation? Or is it just a gentlemen's agreement about this among "lamination guys"?

Not trying to push you into revealing things you don't want to (and I appreciate the info we did get!). Just trying to make sense out of it. And I basically write this because it seems you're in some sort of a dilemma. You did come over to Max's thread and on the one hand you do want to share or at least help making the old materials available again.

BTW do you sell materials, or do you plan to? 

Edit

Moby said:

micaddict said:

Moby said:

I'm afraid that chemical composition is trade secret together with annealing process. It's up to you to listen, compare and finally decide.

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I'm still in a mist here. Nothing wrong with secrets, but exactly who "owns" this 60-odd year old knowledge?

possible consequences with present  Bv.8 replica manufacturers. There is one of them doing it  close enough to original and I think he will be really pissed of if I just put that info in the ear .

Click to expand...

This person X doing it close enough to original according to you, suggests you know at least as much as he does (more in fact). So why wouldn't you be free to share this? Surely anyone who's capable can do his own analyzing and research. But does this mean that the first one who puts something resembling the old product in the market automatically gets protection and others can no longer talk about the details? Or is there such a thing as patent re-incarnation? Or is it just a gentlemen's agreement about this among "lamination guys"?

Not trying to push you into revealing things you don't want to (and I appreciate the info we did get!). Just trying to make sense out of it. And I basically write this because it seems you're in some sort of a dilemma. You did come over to Max's thread and on the one hand you do want to share or at least help making the old materials available again.

BTW do you sell materials, or do you plan to?

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Good questions  As far I know "secret" is owned by Neumann, Vac, Krupp initially, but few more small companies know about it too. I' not sure is it copyrighted but in case it is I will be quet  The problem with making thiss material is not  just because of knowledge. Main problem is that more modern materials are used in nowdays soft magnetic applications such as shielding etc... It's not a big deal for companies as VAC to make it again but they don't see any profit in pro audio since It's small market. On the other hand  pro audio market is overloaded with different (bad,better or good enaugh) replicas of vintage transformers and I'm not sure is it there a space for new replica products.
The other reason I don't want to share info is because I don't want to ruine somebody buisness or to popularize any company or name. Also, It will be hijacking Max thread and hard work. I just answered on alloy chemical composition question .
Do I have a plan to produce it?  Well, it's possible but we will need a serious number of guys to be interested. We can start a new thread and  put the feeler about it. Also, if Max's lamination is made with exact chemistry there is no need to do that. We still have not that answer, just that it's  proper dimensioned and that coils are wounded based on Neumann's blueprint. I can only judge from the picture (same as you) and it looks a bit "blacky"  (black oxide) what can be the product of different annealing process. Did I miss some answer? Probably yes, but this Ipad's screen is so small for me

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It's not copyrighted, because if it was copyrighted it will had to have a patent and everybody should be able to find searching over patents, since there is no patent about there isn't also a copyright. Ruining somebody business I don't think since like I've said two of the main builder of transformers replica were wrong about exact percentage of nickel content, so the only effect in the "revelation of this secret" will be that everybody can ask to the builder the chemistry formulation of alloy and only the correct one will gain the right to claim about "historically correct" replicas, I think that in the microphone section of a forum about diy this should be the right thing to do. Anyhow if you want to keep this secret for selling it to someone you can do it, but I think that you should tell it clearly

Fra

Food for thought.

Someone suggested a new thread for the discussion of lamination materials...  excellent idea.

This kind of thread is one of the reasons I don't post that much anymore.

ioaudio and Moby did work to figure out the lams and treatments.  Did anyone else that asked for information do any work themselves?  Would they even know what to test for? 
I would not give up the information for free.

Since the shoe doesn't fit, I won't wear it.

And one of the the reasons I love to post here I the positive spirit displayed by most. 

If Moby's claims are true, the easy way to resolve the issue is to have Max send Moby some lams to see if the chemistry corresponds with Moby's findings. If it is the same, Max will have a major selling point. If not, then maybe Moby (sorry for the alliteration) could share his knowledge, and a correct re-creation lamination could be produced. Either way it would benefit the DIY community.

-James-

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I was wondering also if maybe the discussion about the transformer core material should have it's own thread. It is facinating stuff and obviously a very passionate subject. Metallurgy is an incredable science but also a bit of a black art much like acoustics. My two cents now in.

Max as the proud owner of an MK47 kit hows those bodies coming along?

+1 with PIP

Moby, I see your point about sharing community, but frankly, there is some limits to invest time into a project and found solutions to problems without a small gratification in the end.  I personally don't have a problem with him not sharing some of this info's. I am happy to pay iaudio money since his selling price is very low for the efforts he is putting into this and I think it is fair. Be careful when you claim he is not sharing because I believe he is sharing a lot already. I agree that you open your own thread about lamination though.

I think you make some valid points regarding the alloys, as have been adressed in the secondary thread.  However, making a 47 clone does not have to be an exact representation of the original.  There are many reasons for this.  For example, early mics such as the 47 were designed to sound good on tape machines.  For the most part, tape machines are not used today.  There are a substantial number of differences between a recording done on a tape machine vs. one that is not. 

Things like harmonic saturation, tape compression, tape eq, degraded high frequencies, fat ass bass, and many other characteristics are present when tape is used.  Without tape, the microphone and the preamp should be able to do many of these things by themselves, but obviously differently.  Instead of having too much high end to account for tape degradation, a microphone should be just right for digital recordings. 

On the other hand, the U47 did a lot of things better than most other mics throughout history.  The mids were perfect, the casing and body was perfect.  Things like the alloy in the transformer were great, and imparted a significant character to the microphone.

The question that should be asked today is not what the exact technical specs of the original transformer metals were, but what are the exact specs of the transformer metals that will impart the same sweetness as the original metals did, but on digital mediums.  For this reason, knowing the exact specs of the orignial alloys is not only incredibly important, but outright necessary... For someone to build a great microphone with u47 characteristics in todays era, an engineer must not only know what the original alloys were, but know why they were.  They must know how the smallest changes in alloy affect tone, and that is not an easy task.  You need good ears for this, and you need a mind which accounts for factors which the average person does not understand. 

In the end, the perfect transformer for the best digital recordings and even for high frequency DSD, will be different from the original Neumann.  SO, don't despair that this alloy is not exactly the same as the original.  Become a scientist, and examine variables such as when individual metals change as all other variables are the same.  Science is a beautiful thing if applied with a mentality that accounts for the artistic elements. 

Yes, this is important, but your method of encouragement is lacking.  Requiring the gentleman to duplicate the original alloy is neither prudent nor useful for anything other than a starting point.


Alright, so what is going on with the kit?