Buss grounding for a little amp

[Calamaro]

This is a very little amp project -my first one- with a TEA2025 chip. I know isn't a hifi chip but I'm really learning from it: good for next bigger project. I have a nice little enclosure, my circuit build on a stripboard, an external SMPS (9AC).

Power socket on amp enclosure is a dc one. Rectifiers, filter capacitor and regulator (7809) are part of the circuit, inside the amp enclosure. As the SMPS is double insulated I think it don't need safety earth connection to chassis.

Then my actual problem refers to grounding. I'm planning a buss grounding and I wonder what could be a correct way to do it:

Buss grounding from ac socket to first filter capacitor after rectifier. I read this keeps high current charging pulses in a loop but I'm not sure I really understood
Connection to chassis: from ac socket through 0,01 uF capacitor.

or

Buss grounding from ac socket to chassis (to other end of circuit).

or

Buss grounding from RCA sockets to pcb with connection from them to chassis.

I read a few post and other webpages but honestly I need help
It could be that all these options are wrong... ohmygod then I REALLY need your help... ;-)
Thank you in advance

[Ted205]

not much help but why have you choosen buss over star grounding ?

[Calamaro]

Isn't easiest? Star ground is ok for me, but my doubts remain...

[Ted205]

i would have thought star grounding is easier.

i found this article on nelson pass's site usefull: http://www.passdiy.com/pdf/articles/ground-loops.pdf

after reading it i sorted my amp and i now have no hum

[Calamaro]

Thank you I'm printing it.