Hi John,
Need your help again. As I said,my aim is to process distracted voice to clear voice. For this I am using beaglebone with audiocape (not yet decided if I shall use usb dongle ). What I need to know is, do I have to use an amplifier to amplify the incoming signal in addition to the cape or usb dongle? Thankyou,
For the benefit of the BeagleBoard community, please address these questions to the community and not to me personally. I have redirected my response to the BeagleBoard mailing list.
For the Audio Cape, you don’t need an amplifier, but using one won’t hurt because you can reduce the gain with the codec. However, you do need to bias the microphone which needs a 2V bias with a 2k2 resistor. On the TI website, look for TLV320AIC3106EVM. You can download the User Guide which includes the board schematic. Look at how the microphone is connected. It uses the bias voltage via R7 (2k2). Unfortunately, this pin isn’t connected on the Audio Cape so all you need to do is use a 2V regulator and a 2K2 resistor to connect this to the Microphone bias pin.
http://www.ti.com/lit/ug/slau209a/slau209a.pdf
Regards,
John