Grounding TA2022

[K i n g p i n]

According the datasheet of the Tripath TA2022 pin3 VN10GND should be connected to PGND also earth because of the screen/shielding of the chip.

The board has a grounding system where the following parts are ground together:
- 0 of the symmetrical ac input
- the "-" of the unbalanced input
- the "-" of the speaker terminals output

What's best practice to ground these to mains earth?

 

[K i n g p i n]

Nobody?

According the spec sheet i see that they ground the "-" terminals to mains earth.
Is it "normal" to wire 2 cables straight to my mains earth star-point (chassis and screen of transformer)?

 

[K i n g p i n]