I found the problem but i don’t know how to fix it.
When i use one RPI with multisqueeze the Audiophonics USB DAC works well without delay.
When i plug a second raspberry with multisqueeze and others DAC (other brand, cheap dac for computer) I have a delay.
I don’t understand why another raspberry on the network cause this delay.
If i use only cheap DAC on the two RPI i don’t have delay.
So i send the Audiophonics USB back.