Is Dietpi can support the hifiberry amp2? I’ve enabled hifiberry-amp in audio options of dietpi-config but no sound. 
Lat Dior
RPi does not natively support a hifiberry-amp2 overlay, just hifiberry-amp. Not sure if the latter supports all versions, needs investigation.
Perhaps we can enable support by installing the required overlay from external source.
EDIT: Ah reading: https://www.hifiberry.com/shop/boards/hifiberry-amp2/
If the software you’re using doesn’t provide the Amp2 as an output option, you should use the HiFiBerry DAC+ driver as the Amp2 is basically a DAC+ with an integrated power stage.
Please try to select hifiberry-dacplus
If it works we will add AMP2 to the menu entry text.
Yes it works perfectly with this DAC plus driver. Sound is very loud so I changed the value Digital in alsamixer and stored it. Thanks for your help.
Okay thanks for reply. I added the info to the dietpi-config menu:
https://github.com/Fourdee/DietPi/commit/2dc5ef753515482f3c31ee37f195979223d67f57
https://github.com/Fourdee/DietPi/commit/6bcac4481ffdec6b2a93553115fb42ef2768f1d7