Not usable sound

Hey there,
I am a beginner trying to get his way into building own synthesizers.

I have a really hard time getting the sound to work properly on my Zynthian install.
That’s how the output sounds:

(this was the PADsynth)

Here my setup:

    • Raspberry PI 3b
    • Raspberry Touchdisplay (don’t know which version)
    • Using onboard sound
    • currently power supply through a power bank that gives 3,1A (no power issues as no lightning symbol is shown)
    • generic AKAI midi controller

Here a screenshot of the settings:

What am I doing wrong here?
Appreciate any hint.


Here’s what works for me when I’m not using the RPI headphone jack and no soundcard on my zynthian. Try this: Go back to the webconf and under Hardware select Audio. Then select Hifiberry Dac + Light and check the RBPi Headphones box. Click on Save and then click on REBOOT NOW! Finally click on Reboot.

Way better. Thanks.
Last issue:
Now I get this symbol, and always when it’s flashing, the sound crackles a little l.

That indicates the sound subsystem (jack) is not coping and triggering xruns which are failures to process data within assigned time. Each xrun manifests as a click in the audio. Common causes are:

  • Poor PSU - even though a power supply may be specified with sufficient power delivery it may fail for various reasons including poor quality cable / connector, poor design, etc. This has been the most common cause of this issue even when there is no low power indication.
  • Use of headphone output - this adds a significant load to the Raspberry Pi and its use is strongly discouraged. It is generally only used for initial testing / assesment before adding a proper soundcard.
  • Resource hungry engines - some of the sound generators and audio processors in Zynthian are resource hungy and the Raspberry Pi can struggle to run these. Start with something simple like a single Fluidsynth layer with no additional audio or MIDI effects and see if that helps.
  • Raspberry Pi 3 is underpowered for the current Zynthian. It will struggle with many configurations (see previous point). The RPi4 is substantially more powerful and better suited to Zynthian.

I use a RPi3 for development and suffer frequent xruns. I try to minimise these using all the above points but am yet to get it running smoothly. I can generally get it to run without showing the symbol but there are invariably a few xruns occurring during a session.

best option, especially with the low end pi3, is to use a cheap I2S external DAC like the ones based on pcm5102a (for <5$ on aliexpress or amazon) or for best sound quality (high end pcm5242 chip and a rich connectivity) for a really low price (<30$ in France)

Zynthian supports a bunch of audio devices, look in webconf->hardware->audio. You will for sure find something that fits your needs for a couple of bucks and it will highly improve your musical/sound experience.

USB sound devices works too but they consume more current and are not always Xruns free :frowning:

Thanks guys.
Your help is greatly appreciated.

I just ordered a cheap audio interface to start with. With the orig. Raspberry Power Supply many of my issues are gone.
I will keep building.

Great community <3