Group buy--Nickel Lamination for Mic Trafos

[adrianh]

rafafredd
Lundahl used mu-metal and amphorous cores no cobalt.

Marik and group
My friend is the applications engineer with Mag Metals.
I am forwarding his contact info to Marik.

 

[rafafredd]

I know, Adriahn. I was just asking if Lundahl does the total interleaving thing...

 

[Marik]

Slightly off topic.

When I moded two Nady 1050s I payed attention that they sounded very different. One of them was an older version, and another newer. I few days ago I pulled their trafos from my junk box and payed attention that a newer had different lams. It looks more "shiny metalic" then "gray" older one. Any ideas as for materials?

 

[SonsOfThunder]

[quote author="Marik"]Slightly off topic.

When I moded two Nady 1050s I payed attention that they sounded very different. One of them was an older version, and another newer. I few days ago I pulled their trafos from my junk box and payed attention that a newer had different lams. It looks more "shiny metalic" then "gray" older one. Any ideas as for materials?[/quote]

CJ could pipe in here, but I'd guess that the shiny one has more nickel content. I'll have to open mine up now and look!

Charlie

 

[adrianh]

Rafafredd
I did not understand the interleave question????

Marik
The cat is out of the bag. Got this from my Mag metals friend.

This is from the fine folks at Magnetic Metals they supplied me with this test method to identify electrical steel.

HOW TO IDENTIFY ELECTRICAL STEEL
1. Clean the surface of the material thoroughly with fine emery cloth.
2. Place a small drop of copper sulphate solution on the cleaned surface of sample to be checked.
3. Check the reaction chart below.

EXPIRED TIME........SURFACE CONDITION ........MATERIAL OR LAMINATION IDENTIFICATION
Immediate.............Brown or Black Spot...........Ingot IronCold Rolled SteelSilicon Steel
60 Seconds............Reddish Brown Spot........ ?Low Nickel? (47-50% Ni)
60 Seconds............No Change........................?High Nickel? (80% Ni)

Be carefull with Copper Sulphate.
Neither I , Magnetic Metals, or Prodigy Pro take any responsibility if you hurt yourself.

 

[rafafredd]

CJ said that he would try TOTAL interleaving. That means: one primary layer/one secondary layer/one primary layer/one secondary layer/one primary... ad infinitum :green:

So, I was just asking if that´s not what Lundahl does...

nice test! I was looking for something like this!

 

[adrianh]

Lundahl has so many different coils for their transformers but they do
a lot of interleaving as all good transformer vendors do.

If you look at a typical mic input transformer each section of the windings are brought out seperate to the terminals. So you could have 4 sections to your input winding which will allow you to interconnect them in many ways.
That is why they have so many pins.

 

[Marik]

Thanks Adrian,

Now tell me where I get copper sulphate solution.
In any case I am waiting for lam samples, which should be here next week and see how much difference it will make.

 

[crazydoc]

[quote author="Marik"]
Now, let's do it organized. First of all, I need quantities you guys need. Since they sell it by pound, it would be harder, however, to calculate total quantity and prices if you need let's say 40, or 100 pieces. I guess I will need to get a scale, as well, so it would be less time consuming to sort before shipping. Any ideas which scale and where to get it?[/quote]

Since they are 0.014 thickness, this would be about 70 pieces per inch (you could count to confirm this) and then just partition them by the inch. Assuming they come stacked.

 

[adrianh]

copper sulphate

It is a brightly colored "crystal"
sometimes can be found to kill algae in ponds.
Try a well old time stocked drug store.
Try a farmers supply store.
Try a fish pond store.

 

[G.]

I spent two months to get Mag Met nickel laminations in Europe without success..
I am looking for approximate 1 kg per both:
1. 375UI8414 - ~1 kg
2. 18DU8414 - ~1 kg
Maybe someone can tell me how to order them direct ?

 

[CJ]

"In Cobalt, there exists a very special substance that exhibits the best of both worlds; on one hand, there is incredibly high permeability, yet great power handling (high flux) - In other words, you have a material that is extremely sensitive, yet can handle anything it is called to do. The cobalt transformers essentially provide unrivaled low level detail and resolution, surpassing the best materials."

Lifted from http://www.magnequest.com/cobalts.htm

Mag Metals has all the lams/inch and lams/pound in their catalog.

As far as Silicon, your talking about M6, which is used in power applications (where you actually have some current flowing in the transformer, ac/dc etc.)
So it's used in pwr x-formers, output transformers with dc, parafeed chokes that handle some milliamps, etc.

Think of a transformer core as a vacuum tube.
Think of the coil as the source feeding the vacuum tube.
The source can either be high impedance (guitar pickup) or low impedance (Shure SM57)
The source will dictate how many turns are on the transformer.

The Core:
Core as a 12AU7: more current handling capabillity but less gain than a 12AX7. Probably less distortion. More headroom. This would be perhaps 49 percent Nickel.

Core as a 12AX7: more amplification factor, (more permeabillity means more inductance per turn) but lees current capibillity (saturates easier than a 12AU7) Less headroom. More distortion. This would be your mu metal, 80 percent Nickel, etc.

Core as a 6L6: Tons of current, low perm, low distortion, good in incremental inductors (DC in the core) This would be your M6.

Kind of a lame analogy, but what else is new!

Mu Metal is a patented blend. I do not know if the patent has expired, who is making it now, how many permutations it has evolved into. I tend to think of any 80 percent blend as some form of mu metal.

Yes you can judge nickel content sometimes by eye.
49 looks different than 80, etc.
Also look for grain orientation. Sometimes they roll it out differently to get the flux right at the corneres and other joints. The rerally old UTC's and WE's used non grain oriented.

:guinness:

 

[Marik]

Thanks Chris!

Now even I, with my big but empty head, finally got it :green:

Could you do the same primer on coil windings, and thoughts about the way they did it in Chinese mics?
Please include in equasions 6SN7 and/or AC701, if it is all possible :guinness:

 

[tk@halmi]

CJ,

Did you know Zero Cases makes nice mu-metal enclosures that are cylindrical and have lids that slip inside the top? In a word, perfect mu-metal input transformer cans.

Tamas

 

[CJ]

Thanks Tamas!
I downloaded that cold drawn pdf.
Now all I need is a winding machine and I'm in bussiness!

:grin:

 

[Marik]

Today I got Ni samples and relamed MXL2001 trafo. I did not have enough time for extensive recording and listening, but immediately, as Chris has predicted, could hear much better bass response, and better overall tonal balance.

Chris, what do you think--will be Cobalt worth trying, or the way coil wounded is a limiting factor here?

 

[shmuu102]

whats the chance i could use these lams for pultec inductors?

(handwinding those small torroids is far from a good time)

 

[zebra50]

but immediately, as Chris has predicted, could hear much better bass response, and better overall tonal balance

Hi Marik,
What mic/setup were you doing your test in?
Stewart

 

[Marik]

[quote author="zebra50"]

but immediately, as Chris has predicted, could hear much better bass response, and better overall tonal balance

Hi Marik,
What mic/setup were you doing your test in?
Stewart[/quote]

Stewart, it was MXL 2001. I have unmoded, as well, so I could compare them directly.

 

[zebra50]

Good!
Both of my 2001s are currently tube-modded (and currently without the original trannies - I think you know why :green: ) so it's good to know it makes a difference in the original circuit.
:thumb: