ground loop layout

[mosfetmaster]

Hello,

I'm reviewing ground connections in my mosfet amp. Here is just a schematic of ground lines, from inputs (on the right side) to outputs (on the left side):

Is it correct, in your opinion?
Should I realize the red connection between the three power supplies?

thanks

[h_a]

You will need to tie the power supply grounds together at some point as otherwise the individual supplies are floating and that will lead to DC-problems between stages (or AC coupling is needed).

Also I'm not sure about exact ground routing between modules here, usually one connects signal grounds and separates them from corresponding power supplies (with e.g. resistors).

From what I see you connect power supply grounds and use this dirty ground as signal ground which is likely to ask for problems.

By the way, Douglas Self has a lot of great info on grounding.

Have fun, Hannes

[mosfetmaster]

Thanks for the reply Hannes.

You will need to tie the power supply grounds together at some point as otherwise the individual supplies are floating and that will lead to DC-problems between stages (or AC coupling is needed).

So, the red connection in schematic is needed...

Also I'm not sure about exact ground routing between modules here, usually one connects signal grounds and separates them from corresponding power supplies (with e.g. resistors).
From what I see you connect power supply grounds and use this dirty ground as signal ground which is likely to ask for problems.

Signal and power supply grounds born together on PCBs. I cannot separate them, I suppose...

[AndrewT]

Hi,
your grounding scheme does not follow the advice in here
Audio Component Grounding and Interconnection

[mosfetmaster]

I'll take a look. Thanks.