grounding on pcb designs

[FunkyStu]

Hi All,

I read somewhere (I think but can't find the place where I think I read it ) that on an amp, the input ground and zobel network ground should be routed separately back to the ground star point. Is this correct or can both be linked on a pcb design ?

If anyone has got some useful info on this or wants to give me a lecture on grounding and pcb design please come forward.

Thanks,

- Stu -

[moamps]

Hi,
that is OK. First, position of input and output terminal must be maximal separated. Second, some current flow thru zobel in normal condition, and this current must not flow thru same wire with input circle.
I look in few books (Self, Slone, Elektor); zobel current circle is separated.

Some authors place zobel on output speaker terminal.

Regards

[Shaun]

I usually define two grounds: Signal ground and Power ground, then connect these with a zero ohm link. So power, decoupling caps and zobel connect to Power ground, and input signal ground and feedback ground connects to Signal ground. On the PCB, the zero ohm link connects the two close to where the 0V connection is. Also, this area would be a star point on the PCB.

This way, the signal ground is kept fairly clean, free from power supply surges.

My 2c

Regards
Shaun

[FunkyStu]

Ok guys, thanks for your help. That nicely answers my question.
Of course if anyone else has any info they think would be useful, please let me know.

Cheers.

Stu.

[Tube_Dude]

Hi Shaun!

My 2c

Valuable 2c...your post is a syntectic and correct.descripton of grunding arrangement well done!

I hope the begineers here take a good look at it!

Regards