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PCM2705EVM-U: Noise issue

Jonathan Navor
Genius 9475 points

Part Number: PCM2705EVM-U
Other Parts Discussed in Thread: PCM2704

Hi Team,

Good day! I am posting this in behalf of the customer.

There is a noise whenever using the device PCM2705EVM-U.

I've reinstalled the board to give you a fresh diagonistin report. 
After plugging in the board (and wearing an antistatic arm band) to the usb port on my HP Compaq dc7000 minitower currently running windows 7 Pro, and 8 Gig of ram, and plugging in my headphone 3.5 mm stereo jack into the female jack on the board, I heard several soft pops on the head phones.
With no sound (except the system audio beebs at boot-up and starting the few operating programs) being output, several softer POP's were heard, that shouldn't have happened. Meaning, with other boards, no sound is heard at all at bootup except the windows welcome and the starting and so on of the programs.
With the computer on for a few seconds (about 20) several POP's were heard again while doing nothing with the computer.
I started a program, [NewsMax] so I could hear and experience what the board would do. Aproximatly after ten seconds, the audio would stop and the computer would post a message, "An audio device was connected or reconfigured verify that the audio is connected, and then try to play the item again." And so the device would periodically (about every thirty seconds or so) stop playing and redisplay this same message. ZAnd still, about every thirty seconds or more, that 'POP' would be heard.
But after approximatly ten minutes, it wouldn't work (no sound) at all.
So, I rebooted the computer to see if that would re-establish the unit, but it did not.
Also, all this was done with the three switches, SW1 turned on (the toggle switch was switched to the left, as the board was positioned with the board text properly alligned) and 2 & 3, were switched to the right.
The board got it's power from the USB. JP1 - closed, JP2 - open; JP -3 open; JP4 - open; JP -5 open; JP6 - open; JP -7 closed; JP8 - open; (I see no JP9) and JP10 is open. 'Closed' meaning the jumpers were shorting the two pins, and 'Open" being that the pins were not connected.
Best regards,
Jonathan
  • 0
    TI__Mastermind 29220 points

    Hi,

    I will look into issue today in audio lab, thank you for your patience

    Regards,

  • 0 in reply to Daveon Douglas
    TI__Mastermind 29220 points

    Hi Jonathan,

    Please check x107####@ti.com email for troubleshooting tips on noise issue. 

    Further update:  PCM27xx evm is not on hand here and we will conduct testing when evms are delivered to audio lab

  • 0 in reply to Daveon Douglas
    TI__Mastermind 29220 points

    Hi Jonathan,

    I setup PCM2704/5EVM and my procedure follows PCM270xEVM-U User's Guide for USB BUS powered application.

    My jumper settings are as shown below and there were no POPs heard and EVM operated normally. Follow H/W configurations below and see if the result is the same

    SW:1-3 are HID interface and are used to mute or volume up/down CN2 audio output. These are buttons and not toggle switches.

    In addition for design purposes, you can reference below thread for considerations to reduce POP when plugging 3.5mm jack into audio system:

    https://e2e.ti.com/support/audio-group/audio/f/audio-forum/1024852/pcm2706-pop-noise

  • 0 in reply to Daveon Douglas
    TI__Genius 9475 points

    Hi Daveon,

    Thank you for your support. Our customer were able to check your last feedback and here is their response below.

    I have the board now set up with:
    SW1 closed (toggled to the left if the board is orientated with the board printing properly aligned), SW 2 and 3, off (opposite to SW1).
    JP1 - closed; JP 2 - 6 are open. JP7 is closed, JP8 is open; JP9, 10 & 11 are set for 'BUS'.
    The USB from my computer is plugged into the female USB jack on this board, and my headphone jack plugged into the 'CN2' plug.
    And my computer isn't recognizing the board on the USB. And there fore, the board's not working.
    In the past, it was making load 'pop' noised every twenty seconds to a minute's time frame, or so. And as stated before, in past messages, and as now, the device will not be recognized by the computer.
    Best regards,
    Jonathan
  • 0 in reply to Jonathan Navor
    TI__Mastermind 29220 points

    Hi Jonathan,

    Ok this may be usb port driver issue. I suggest checking two things:

    • Check is usb3.0 root hub is updated in device manager or scan USB tab for hardware changes
    • Check if USB AUDIO DAC is the designated speaker after plugging in evm
      • Open sound settings, check PLAYBACK/RECORD tab for 3-USBAudioEVM

  • 0 in reply to Daveon Douglas
    TI__Genius 9475 points

    Hi Daveon,

    Thank you. Here is the update from the customer side. 

    When the device quits, I get a message from the computer; 'An audio device was disconnected or reconfigured. Verify that the audio device is connected, and then try to play the item again.'
    And maybe a couple minutes or 30 minutes go by, and it'll again play audio files again, but only for a very short span.
    After rebooting the computer a number of times, the board [PCM2704] has found (some) life and actually played (part) of a song that I have on this system, but a quarter of the way into the song (I'm Livin' On The Edge, Areosmith), it, once again quit playing anything but every so offten, a load pop is heard.
    And any sounds, computer beeps, dings, etc or audio from a recorded song, is not supported continously! But I do hear those POPs, which sound like a discharge of an electralytic capacitor across a speaker. A load, very short POP and sometimes a crackle at the end of the pop. And it will play part of a tune, but not the whole tune (maybe 5 to 20 or 25 seconds of the song. Then silence but those 'pop's again
    Best regards,
    Jonathan
  • 0 in reply to Jonathan Navor
    TI__Mastermind 29220 points

    Hi Jonathan, 

    Is customer using PCM2705EVM board (mentioned in original question) or experiencing this from custom board with 2704?

    If custom, can you share schematic?

  • 0 in reply to Daveon Douglas
    TI__Genius 9475 points

    Hi Daveon,

    Here is the customer's update. Apologies for the delay.

    No sir, as I stated in the text, I'm using the "PCM2704" board, and sw1-3 is described.  SW1 is on, and SW2 & 3 are off.

    The board's been working, for the most part, but yesterday, it did quit, forcing me to stop whatever I was doing, and reboot.
    That shouldn't happen. And the board has been working, at times, and the length the unit is working is getting longer between the faults, but as stated above, it's still faulting at times.
    Best regards,
    Jonathan
  • 0 in reply to Jonathan Navor
    TI__Mastermind 29220 points

    Hi Jonathan,

    I understand customers frustration and I'm using PCM2704/5 EVM in audio lab with no issue so for debugging purposes can customer share schematic of PCM2704 board they are testing.

    Thanks,

  • 0 in reply to Daveon Douglas
    TI__Genius 9475 points

    Hi Daveon,

    Here is the attached schematic that customer is talking about. 
    Best regards,
    Jonathan
  • 0 in reply to Jonathan Navor
    TI__Mastermind 29220 points
    Jonathan Navor said:
    JP1 - closed; JP 2 - 6 are open. JP7 is closed, JP8 is open; JP9, 10 & 11 are set for 'BUS'.

    I suggest closing JP 2-6 and have JP7 open following screenshot. I also suggest trying a different USB cord.