1. How do I wire it for balanced/unbalanced input to balanced output?
I saw this guide from Lundahl's site (https://www.lundahltransformers.com/using-the-ll1545e/) on how to wire unbalanced/balanced input to balanced output.
Can I use the same guide for other manufacturer's input transformer ( example: Hammond 560G) that has the same "pinout" (unsure of the correct term to use here) as the LL1545e? Only asking since Lundahl's are not easy to find in my location.
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2. I've seen 1:1 and 1:4 transformer? Are pros/cons to the different ratio?
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3: How do I know an input transformer is suitable for unbalanced/balanced input to balanced output application?
I was just looking at the lundahl site, there so many input transformer (example: LL1544a vs LL1545a vs LL1690) that seems to do similar things.
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Thanks a lot
I saw this guide from Lundahl's site (https://www.lundahltransformers.com/using-the-ll1545e/) on how to wire unbalanced/balanced input to balanced output.
Can I use the same guide for other manufacturer's input transformer ( example: Hammond 560G) that has the same "pinout" (unsure of the correct term to use here) as the LL1545e? Only asking since Lundahl's are not easy to find in my location.
-----------------
2. I've seen 1:1 and 1:4 transformer? Are pros/cons to the different ratio?
-----------------
3: How do I know an input transformer is suitable for unbalanced/balanced input to balanced output application?
I was just looking at the lundahl site, there so many input transformer (example: LL1544a vs LL1545a vs LL1690) that seems to do similar things.
-----------------
Thanks a lot
Last edited:
1) Yes, if they have either two primary windings or a centre-tapped primary winding.
2) 1:4 increases the signal voltage by four and the impedance by 16. That can be handy when you have a very low level signal source with a low impedance and want to connect it to an amplifier with a very low equivalent input noise current, but not so low equivalent input noise voltage. Typical example: microphone preamplifier in valve technology.
2) 1:4 increases the signal voltage by four and the impedance by 16. That can be handy when you have a very low level signal source with a low impedance and want to connect it to an amplifier with a very low equivalent input noise current, but not so low equivalent input noise voltage. Typical example: microphone preamplifier in valve technology.
@MarcelvdG another question please.
does the static resistance of the winding matter? Thanks again!
as an example (taken from the screenshot of the respective datasheets):
does the static resistance of the winding matter? Thanks again!
as an example (taken from the screenshot of the respective datasheets):
It has an impact on the losses of the transformer, especially when the transformer is loaded by a smallish impedance. It also determines what load impedance the driving circuit sees at deep subsonic frequencies, where the transformer doesn't transform yet.
Here is some more info:
https://www.jensen-transformers.com/application-notes/
https://www.jensen-transformers.com/seminars/
https://www.jensen-transformers.com/application-notes/
https://www.jensen-transformers.com/seminars/
So what is the application?
Usually, unbalanced inputs are not wired with a transformer. But it can be done. However, not with the transformers you have looked at this far.
Output transformers can be used for input transformers. Some that are gapped would have a little bit of loss, but they all will work.
This transformer might be what you looking for, as I use it for mid/high Z interfacing unbalanced and balanced equipment in stadium and theater installs. The transformers you are looking at is the lower Z transformers used in vintage line level conventions that are obsolete.
https://www.jensen-transformers.com/product/din-2li/