This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TAS5751MEVM: PurePath Control Motherboard and the EVM are not playing sound

Part Number: TAS5751MEVM
Other Parts Discussed in Thread: PCM3168, PCM9211, TAS5751M, TLV320AIC3262

Hello, audio engineers!

I have TAS5751MEVM + PurePath Control Motherboard + PurePath Control 3. There is no sound on the speakers, just very quiet whistle. My Windows 10 Pro is not giving me any chance to install the drivers from USBfirmware_V0354_Home. It is installing some Microsoft driver. The TI USB audio device control panel is not displaing any USB audio device. Yet, Windows is enumerating some USB EVM Audio device. I presume the USB driver is no appropriate, and maybe that is why I don't hear a sound from the speakers. But there is no sound from line in and Coax SPDIF input, too.

So, I need help.

Svetoslav Valkov

  • Hello Svetoslav, 

    Did you perform the hardware checks on the PPC3 app with success?

    All the best, 


  • Dear Carolina,

    The hardware check is OK.

    Last night I studied the schematics, did some measurements and I found that the SDIN signal is not going from PCM9211 to TAS5751M. According to the schematics of PPC motherboard the signal path is out of PCM9211 to BUF1..4 then it is split to 2 chips - a mysterious PCM3168 and TLV320AIC3262IYZF. The TLV320AIC3262IYZF has some DOUT pins and there comes anothe "magical" MUX3..7 which transfer signals to EVM connector.
    Now it looks like I have to have control on TLV320AIC3262IYZF. But I don't have app or tool to do this.

    Any suggestions?

  • Hello Svetoslav, 

    The TLV320AIC3262 is controlled by the PPC3 application, when you select the COAX input it selects the I2C data from the SPDIF/COAX to flow through instead of the external PSIA I2S data, from that it is automatically chosen (by populated resistors) by the muxes to flow to the connector. 

    For experimental purposes can you switch your Audio IO in PPC3 GUI to be USB and see if you are able to have audio play? The experiment would be more helpful if you could do it through optical cable (as this follows the same path as COAX-in), but I understand you may not have that on hand. 

    All the best, 


  • Hello Carolina,

    I tried to switch to USB input but there is no sound either.  I suppose it is some driver problem. I uploaded a PDF file explaining my efforts. Hope you are seeing it. I have it in Word if it is more suitable. TAS5751EVM.pdf

  • Hello Svetoslav, 

    I am in contact with the FAE who has been assisting you, he has told me that he has ordered a new board for you. I believe this to be the correct next step, as the one that you have does not operate with USB input, which leads me to believe it is damaged somehow. Maybe an erased EEPROM? 

    There are two issues addressed in this e2e: 

    1. Coaxial input to the PPCMB: I have personally never had to support this type of input, very uncommon use case. I have checked with colleagues about this input choice and it is not supported on PPCMB. We have taken the next steps to remove the software option through the GUI and will remove the hardware option in our next revision of the PPCMB. 

    2. TI Audio USB Driver: If you suspect that you have the incorrect driver for TI Audio Device the next steps are: 

    a. Open Device manager

    b. Under "Sound, video and game controllers" find "USB-AudioEVM" 

    c. Right click this driver and "Uninstall Device"

    d. Unplug USB, re-plug in USB into computer, this will allow the correct driver to be recognized by the computer. 

    The driver error sometimes occurs when using several TI Audio EVMs (as you can imagine, often here in headquarters). 

    Hope this was helpful to you and sorry for any inconvenience/hardship this has cause for you in the using our products. 

    All the best, 


  • Hello Svetoslav, 

    PPCMB has been verified to work with an AP to the coaxial input as long as the output on the AP is set to “digital balanced.”

    Hopefully you will see this with the new board the FAE has sent you. 

    Sorry for the confusion. 

    All the best,