Signal 0v Ground VS PSU ground?

[Ted Krotkiewski]

Happy New Year friends!!!

I’m here with a noob question regarding Ground principles that has probably been answered a 100 times before.

My scenario is: I have a passive inductor based EQ circuit with its own "0v" audio signal ground.
I also have some active IC components. Most of the IC´s acts as Unity gain buffers within the Passive EQ network and then a IC gain amp at the very end.

From my external dual rail PSU that is powering the IC´s there is also a ground rail. "Shield ground"?
At the moment I have the PSU ground rail leading to the same ground as the Passive Audio signal "0v" ground
Something tells me that it is not as simple as that.
My PSU is an external factory made Eurorack PSU, Not DIY by the way.

Without diving too deep into ground principles, How would you approach ground in my scenario?
I have read @ruffrecords excellent papers on grounding, but I can’t wrap my head around how to apply the theory into my project.

I can ofc submit schematics and pictures if needed.

Thank you for your time.
//Ted

 

[JohnRoberts]

Ground management can get complicated.

Your 0V audio ground is a signal node. It ultimately gets connected to power ground but you need to take care that stray currents don't flow through the 0V node on the way to power ground and corrupts the 0V quality.

JR

 

[gyraf]

The simple solution here could be to consider your passive EQ balanced, i.e. a + and a - line, not using ground.. Or do I misunderstand the question?

 

[ruffrecords]

Happy New Year friends!!!

From my external dual rail PSU that is powering the IC´s there is also a ground rail. "Shield ground"

Thank you for your time.
//Ted

This is what is confusing you, The ground rail from the power supply is signal 0V also sometimes called analogue 0V. Shield ground is something else entirely,

Exactly which PSU are you using?

Cheers

Ian

 

[Ted Krotkiewski]

This is what is confusing you, The ground rail from the power supply is signal 0V also sometimes called analogue 0V. Shield ground is something else entirely,

Exactly which PSU are you using?

Cheers

Ian

Hi Ian.
Nice to hear from you.
Ok. Thats good news for the moment. So in other words, the "Analogue 0V" can share the Signal 0V ground?

PSU:
I use a standard PSU designed for "Eurorack modular synth" format. Powered by an external AC wallwart.
Like this: Eurorack Case
Or in simple form like this: DIY PSU

Thank you!