Hello,
I need to make a circuit to do the following:
A modem on a dev board is spitting out a balanced speaker output, and receiving a balanced microphone input.
I'm plugging that into a USB Sound Card, this guy:
https://www.amazon.com/gp/product/B001MSS6CS/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1
It has a unbalanced stereo output for speaker, and an unbalanced mono input for microphone.
We get bad echo when trying to communicate. I opened up the USB sound card and the GNDs of the speaker and microphone jacks are tied to common GND, which I believe is unbalanced and the source of our problem. Our modem is expecting to be plugging into a balanced microphone and speaker.
FYI when a headset is plugged into the dev board and communicating these same lines it sounds great. What we are trying to do is instead convert it to a USB output to act as a sound card. This is a mandatory part of the process that due to the nature of the project cannot change.
So my understanding is somehow I can fix this using a transformer, but I'm not exactly sure how. Given this (and any more information I can provide if I missed something critical), does anyone know the step(s) I'm missing here to fix it?
Thanks!
I need to make a circuit to do the following:
A modem on a dev board is spitting out a balanced speaker output, and receiving a balanced microphone input.
I'm plugging that into a USB Sound Card, this guy:
https://www.amazon.com/gp/product/B001MSS6CS/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1
It has a unbalanced stereo output for speaker, and an unbalanced mono input for microphone.
We get bad echo when trying to communicate. I opened up the USB sound card and the GNDs of the speaker and microphone jacks are tied to common GND, which I believe is unbalanced and the source of our problem. Our modem is expecting to be plugging into a balanced microphone and speaker.
FYI when a headset is plugged into the dev board and communicating these same lines it sounds great. What we are trying to do is instead convert it to a USB output to act as a sound card. This is a mandatory part of the process that due to the nature of the project cannot change.
So my understanding is somehow I can fix this using a transformer, but I'm not exactly sure how. Given this (and any more information I can provide if I missed something critical), does anyone know the step(s) I'm missing here to fix it?
Thanks!