Wav Trigger - click/pop at the end of playback

Sensors Sound & Audio
1

Hi,

Using the Wav Trigger I’m an experiencing a quite loud pop as soon as soon as the last sample being played stop. So, not one pop at the end of each sample, just one pop when the playback of all samples stops. The volume of the pop is independent from the volume of the sample.

Things I have tried to get rid of the noise and the pop:

  • - Various way of powering the device: barrel with various independent power supply, 5V through FTDI with closed %V jumper
  • - Turning ON/OFF onboard amp
  • - Try with the Wav Trigger not connected to anything else beside power and headphones
  • - Various fadeout configuration

    • The result is always the same.

    Any idea what can be wrong?

    Audio recording showing the issue (the pop is at 7sec): https://www.dropbox.com/scl/fi/c9gztnvu … 41z5s&dl=0

    Thanks!

    2

    I’ve not heard of this issue before. Do you know if you’re running the latest firmware? Did you purchase the WAV Trigger from SparkFun and if so, when? Have you updated the firmware?

    The PCM5100 DAC has an intelligent mute function described in the datasheet:

    "The PCM510x has a zero-data detect function. When the device detects continuous zero data, it enters a full

    analog mute condition."

    Your description makes is sound like this might be involved in some way. One thing that might help diagnose the issue is to try wave files containing only 0’s or silence. You say it only pops when all audio stops. Is this true if the last audio playing contains only silence?

    3

    Thanks for the quick reply!

    I’ve purchased the WAV trigger from mouser on Dec.4 2023. I’ve confirmed that I’m running the latest firmware.

    Your hypothesis of the full analog mute condition makes sense. When playback is engaged I can always hear some light noise and it definitely stop (with a pop) when nothing else is playing anymore. I will do some test with 0 level audio samples and report back.

    Thanks!

    4

    Just tested with 0 level samples and the pop is not happening, but the pop will still happen if any other normal samples were playing, regardless if the 0 level samples playback happens at the end.

    Also, with normal sample, while listening more carefully I now realize that the pop is also happening at the beginning of the sample playback. The sound seems to also be slightly degraded, similar to FX which intentionally lower the number of bits.

    attaching a picture of my little project, super happy with it, if only I could fix this weird issue!)

    Thanks for your help!

    IMG_9200.jpeg
    IMG_9200.jpeg4032×3024 1.32 MB

    5

    That’s a pretty impressive looking keyboard.

    The WAV Trigger should definitely play sounds without clicks and pops - it’s been used in demanding situations like commercial keyboard instruments. I always suggest simplifying when troubleshooting, which usually means disconnecting everything except power and headphones, but it sounds like you’ve already done that. Can you possibly create a 2 or 3 second 440Hz sine wave file (making sure that the waveform starts and ends on 0, i.e. an even number of cycles) and record the output?

    Also, I don’t suppose you have more than one WAV Trigger - to rule out a hardware issue?

    6

    Thanks again for your help, really appreciated!

    Good idea with the 440hz wave.

    Unfortunately the result is the same, the pop is still audible.

    In the linked file you can first hear the 440hz with proper cross zero at the beginning and end followed by an ordinary Vibe sample.

    https://www.dropbox.com/scl/fi/109wnuy2 … 5eaxn&dl=0

    Let me know if you spot something I might be missing.

    I have no doubt the WAV trigger is not suppose to do that, it looks like a very professional device with a good framework and documentation. I must do something wrong or I have damaged the unit in some way during my whole build process. To discard this option I have ordered another one, will see.

    Cheers,

    7

    Found the issue!

    All my fault of course :roll:

    TLDR: I was connecting the stereo output to a mono TRS input!

    So in all my test scenarios, even the simplest, I was STILL going through my Mackie mixer… in a TRS mono input, feeding a stereo input! So all the weird noise and pop were most probably due to the balanced invert polarity thing doing his trick which was also forcing me to amplify the output a lot.

    Everything is working as expected now.

    Thanks again for your help troubleshooting this!

    Cheers,