Only buzzzz sound at Pi headphones output

Hi all,

Still trying to get Zynthian software and a cheap 3.5"TFT up and running (probably before I buy a set because this takes longer than I want).

Headphones output should be good enough for my purposes (well if the delay is <512) so I am trying that. But, I do not hear any sound when I select any synth, just a high-piched buzz when I hite a note. Sounds like a buffer-mismatch, and only a very very very quiet actual sound of a synthtone.

I invested about 2 days fiddling around and ended up with:

  • burn the image
  • not having ethernet hardware, changed ZYNTHIAN_WIFI_MODE to “hotspot” in /home/pi/config/ and visit
  • set these options in the web front:
    menu Hardware - Kit: Custom
    menu Hardware - Audio: Rbpi headphones
    menu Hardware - Display: PiScreen 3.5 (v1)
    menu Hardware - Wiring: Dummies
    menu Interface - Terminal
    sudo nano /etc/X11/xorg.conf.d/99-calibration.conf
    • changed Option “CalibrationMatrix” “-1 0 1 0 -1 1 0 0 1”
      to Option “CalibrationMatrix” “-1 0 1 0 1 0 0 0 1”
  • hook up my synth, select synth layer and sound (painfully difficult with a pen), hit a note and listen to the buzzz

Anybody any idea what’s wrong?

Instead of selecting Rbpi headphones in the Hardware -Audio, try selecting Hifiberry Dac+ Light and check the RBPi Headphones box at the bottom and click Save. This works for me on one of my zynthians that doesn’t have a soundcard.

1 Like

Bingo, that does the trick. Super thanks!

I faced a similar issue which was caused because the sample rate of the audio being played not being natively supported by the internal hardware (hw:Headphones).

I managed to solve the issue by using plughw which does automatic sample rate conversion on the fly. To do that, in the audio config page you can try to switch out hw:Headphones with plughw:Headphones which should solve the issue instead of using the workaround as mentioned above.

Sorry to say that your solution didn’t work out for my setup. ( I think my problem is that my Korg trinity taktile is not only a USB MIDI i/o but also an audio output. )