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

[mudevilo]

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.

 

[ruffrecords]

What is an AOP???

Cheers

Ian

 

[mudevilo]

What is an AOP???

Cheers

Ian

OPA ...
operational amplifiers ...

 

[thomasdf]

AOP stands for ampli opérationnel, in french ... Since GDIY is an english speaking forum you'll have more luck with "opamp"
the NE5534 is a great candidate

 

[TwentyTrees]

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.

 

[mudevilo]

AOP stands for ampli opérationnel, in french ... Since GDIY is an english speaking forum you'll have more luck with "opamp"
the NE5534 is a great candidate

excuse my very poor English...
indeed I am French!
Thank you for your answers...

 

[abbey road d enfer]

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..

 

[mudevilo]

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..

Thank you for these clarifications

 

[Newmarket]

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..

Why the focus on autotransformers in the comment. Not seeing any suggestions to use them. Did someone suggest then delete ? Agree with the point wrt galvanic isolation of course.