UTM INDUSTRY audio transformers - from Poland - EU

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I'm curious also so I'll restate the question.

There's definitely some typos on this description because the numbers are inconsistent with each other. Is the secondary 10k, 50k, or 60k? The description says all three in various places (in bold). ratio = sqrt(sec/pri)

From the website:

UTM2572
This is 1:10 or 1:20 mic or line input, high ratio, 150/600:10k, transformer. Recommended for vintage Telefunken V72 circuits. Also suitable as a high-ratio input transformer with high level capability for tube mic preamps.


Ratio: 1:10, 1:20
Impedance: 150/600:50k
yeah I hope it's the 150:50k. What concerns me is if they succeeded in getting good bandwidth despite the small size and high ratio. No AP sweep for this one. Would also like to see recommended secondary termination/zobel values.
 
yeah I hope it's the 150:50k. What concerns me is if they succeeded in getting good bandwidth despite the small size and high ratio. No AP sweep for this one. Would also like to see recommended secondary termination/zobel values.
All of the specs for this transformer are contradictory. Most likely the ratios are 1:10 and 1:20. The primary inductances are listed as 2H+2H so the 1:10 ratio will have a primary inductance of 8H which is about right for use with a 150 ohm source (reactance just over 1K ohms at 20Hz). At this ratio you would normally load the secondary with 150K so that this would be reflected back the the primary as 1500 ohms which is an appropriate load for a 150 ohm mic. If you parallel the primaries the inductance is 2H and the 150K secondary resistor is reflected to the primary as 375 ohms which is a reasonable load for a 50 ohm microphone. The reactance of 2H at 20Hz is 250 ohms so again reasonable for a 50 ohm mic. But you will not really be able to use a 150 ohm mic on the 1:20 ratio.

Cheers

Ian
 
It probably works best as 1:10 150:15k. I would add that the real problem with low primary inductance is not so much the low freq response but the low freq distorsion it adds in combination with a small core. In 1:20 or or in 600:50k the hi freq response probably suffers due ro the very high secondary impedance.
 
commercial sales should use a white market account

JR

I stated this thread not member igs neither anyone from UTM.
I started it so we could get more information on UTM transformers and specs.

There aren't any products being sold in this thread, there's no commercial sales being discussed here, just information about transformers. This is an information thread where only Q&A is done

The rules of the forum clearly say (Ethan's Rules):
"3. Topics involving the exchange of money should be kept only to the Black Market or White Market."

There was not any topic or any post "involving the exchange of money" in this thread, so no forum rules where broken.
So what's the problem and what's the reason you posted that message here?
 
Trying to make sense of this, my white market comment ended up in a different thread than the reported post. It should be hard to do that since reported posts include a link to the post...

Now I will have to post the WM warning over there and try to clean up this... mea culpa.

JR
 
Hello to all.
I really apreciate all the contribution to DIY community that members of this forum give all the time, this is priceless :D I've been quiet reader of forum posts for some time now, and all of this is really quite interesting way of knowledge and experience gathering :)


@igs I found about this tread only Yesterday, and I am currently in serach for good quality transformers for some of microphone builds that I do for my brother's studio. I wanted to contact You somehow about some details on ordering, that maybe are not so of interest for other forum members, and I am not still able to send PMs as I am still new member with not enough posts (Which I'm willing to change soon for sure).
Is there any way that You contact me in PM, or share some other contact?
 
Not sure if this was already ask before, but is there any BV107 replacement aviable at your store? For LDC KM84 builds.
Or just go for the 547 6:1 trafo?
But I would like to have something closer to 7:1 or 7.5:1. Thank you!
 

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