Replacement Laminations for Chinese Transformers

[HellfireStudios]

I've tried contacting magmetals about getting some sample lams. They had a sales rep call me, and told me I could get the old Neutrik transformer composition lams (he claims mag metals used to provide their lams before Neutrik outsourced their manufacturing to China) or the superperm. He also told me he would email his contact info which never happened. Now, as I don't seem to be able to obtain samples from magmet, I must reach out to you guys for the laminates to redo a standard Chinese mic output transformer. Does anyone know of somewhere else to get lams in small quantities? Thanks.

-James-

 

[zebra50]

What size are they? I might be able to find a few?

 

[MatthisD]

If it is the size below then 'Long E 25' from ebay: 230634371529 is size compatible and result in about 3 to 3.5 times more inductance when compared to the low nickel laminations from a SE2200a mic output transformer which are the size here;

http://www.magmet.com/lamination/25ei.php

 

[HellfireStudios]

I'm not sure what dimensions you need, but I'll list them below. There are two different pieces. An "E" shaped piece and a rectangular piece. I would need nineteen of the "E" pieces and seventeen of the small rectangular ones to re-lam this particular transformer.

Here are the measurements (let me know if you need any other ones):

"E" piece: 31/32" x 5/8" or 25mm x 16mm

Rectangle: 31/32" x 1/8" or 25mm x 3mm

Thanks again.

-James-

 

[zebra50]

Ok, it sounds like you might want the ones that Matthis mentions above.

I have some small EE lams, but not EI at that size. The "I" is your rectangular bit.

 

[HellfireStudios]

I just had a moment of clarity. I was not sure what the letter-designated sizes meant until just now. EI would be the combination of an E shape and an I shape, EE would be two E shapes, etc. Wow. I feel dumb. I'll check out those lams as soon as I can. Thanks again.

-James-

 

[HellfireStudios]

I pulled the trigger on those ebay laminates MatthisD recommended. Should I be worried that they are coming from Korea? It's not a large outlay of cash, but I don't want to do all the work for no improvement or worse... Thanks.

-James-

 

[zebra50]

No, don't worry about it. Much of world's electronics industry is out east, and if Matthis has tried and measured the inductance then they should be OK.

Anyway, please measure and report back!

 

[HellfireStudios]

I appreciate vote of confidence. I'll have to research how to measure the inductance of laminations, and see if I have the right test equipment (I have a feeling my DMM won't do the job). I'll report back when/if I'm able.

Thanks for all the help. This place is amazing. I could not have had the quality of equipment at these price points without the volumes of knowledge accumulated here. Once again, thank you all.

-James-

 

[MatthisD]

but I don't want to do all the work for no improvement or worse... Thanks.

-James-

This lamination is only one E piece per layer which is a similar idea to a DU lamination or a Neve input transformer using a U with no I. Also it is 0.2mm thick instead of the more common 0.35mm thickness so you'll want to be careful handling them so they are not bent at all when stacking. I would be careful removing the old lams too so they can be reused rather than binned.

It'll certainly change the characteristics of the transformer but whether worse or better would depend on an awful lot of factors.
Matt.