Hi, On 10/3/21 11:33 PM, J P wrote: > Hi, > thank you. > > It does not seems to work. I get all null samples when recording. > Which dsp device are you recording from? > Maybe it's a matter of gain? How do I control gain with virtual_oss? You can install virtual_oss_ctl to control the gain. I tested with SOX from ports and it works fine here: env AUDIODEV=/dev/dsp9 play somefile.wav & env AUDIODEV=/dev/dsp9 rec somerecording.wav --HPSReceived on Mon Oct 04 2021 - 07:21:02 UTC