Drive an audio transformer from an AOP. Good or bad idea?

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mudevilo

Member
Joined
Feb 3, 2022
Messages
20
Location
FRANCE
Hello everyone.
I read on an electronics website that it was not recommended to use an AOP to drive an audio transformer.
Transformer which will be used to balance the signal output from a microphone for example whose amplification will be managed by AOP.
The electronics engineer on this website says that it is necessary to insert a transistor-based assembly between the AOP and the transformer, because transistors have a higher current capacity than AOPs.
What do you think?
Thank you for your feedback.
O.
 
Hello everyone.
I read on an electronics website that it was not recommended to use an AOP to drive an audio transformer.
Transformer which will be used to balance the signal output from a microphone for example whose amplification will be managed by AOP.
The electronics engineer on this website says that it is necessary to insert a transistor-based assembly between the AOP and the transformer, because transistors have a higher current capacity than AOPs.
What do you think?
Thank you for your feedback.
O.
As with everything, it depends on the application. Some op amps are perfectly happy driving some transformers, some less so.
 
Hello everyone.
I read on an electronics website that it was not recommended to use an AOP to drive an audio transformer.
Transformer which will be used to balance the signal output from a microphone for example whose amplification will be managed by AOP.
The electronics engineer on this website says that it is necessary to insert a transistor-based assembly between the AOP and the transformer, because transistors have a higher current capacity than AOPs.
I disagree on the principle.
The current limitation is the same with a normal xfmr (separate pri and sec) as well as an autoformer.
If the primary inductance is too low, it draws too much current.
If the ratio is too high, it draws too much current.
It is perfectly possible to drive transformers, of any sort, with an opamp, as long as the reflected impedance at the primary is in accordance with the opamp's capabilities.
Yet, the main reason for avoiding an autoformer is that it does not offer galvanic isolation between primary and secondary. Connecting it to an unbalanced input would be disastrous. In addition the connection is not impedance-balanced, which is the most important aspect of a balanced connection..
 
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