Haufe T8845 - what to do with it? ( datasheet inside )

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rock soderstrom

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Hi guys, I just stumbled across this Haufe transformer and was wondering what to do with it.

The datasheet is not very informative, the transfer factor strange.  Could it be reinterpreted as 1:30?

Is the transformer perhaps suitable for a ribbon microphone?

Ideas?

 

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volker

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The transformer has an overall noise resistance of 134R. The Lundahl LL2912 at 1:37 has 127R. So I'd say it's definitely in the right ballpark to give it a try.
Inductance would be roughly 3mH. Could result in a bit of bass shyness, that depends on the resistance of the ribbon.
 

rock soderstrom

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Thank you Volker! Do you think that the slightly smaller transfer ratio can be a big problem? I guess I just have to dial in more gain at the mic preamp. Right?

One more question, how do you come to the 134R noise resistance? Can you enlighten me, I am a little clueless? 😅
 
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volker

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I would just try it out. It won't be the lowest noise possible, but I think it will work ok. Like I said, I'm not so sure about the bass response. I don't know how a ribbon transformer is usually wound in that regard, whether they aim for maximum power transfer or rather a bridging load.

Calculation: take the primary resistance multiplied with the square of the transformer ratio plus the secondary resistance.

NR = 0,13R x 30² + 15R
 
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