Different grounds

[Teddeeh]

So im wondering how to get different ground routes in diptrace. I see there is a common ground attached to the ground plane, but there is also another ground that is attached to the ground at some point but dosent clip to the ground pour. Can anyone help me out? Ive made a couple of pcbs so far but i think im getting alot of unwarranted noise because all my grounds are hitting that ground pour. Would it be easier to not attach the ground net to the copper pour and manually attach those points later? Or is there a way i can have common ground attached to pour and 2nd ground in its own route, attaching to the ground at a certain point?
I hope this makes sense. Apologies if its gibberish.

 

[bean]

It's not gibberish. IMO, there's no reason not to attach every ground point to a pour in both the top and bottom layers (for analog guitar circuits). The only time I don't do this is either I'm using a 4 layer design (meaning only one inner layer has a ground pour) or I'm dealing with a compact design that has some sort of clock, modulation component or other special component. In those cases I often create separate ground pours from the audio path that are connected by a single trace to unify them. In Eagle this is done by creating polygons around the PCB and simply renaming them to the ground net. Don't know about Diptrace though.

 

[Teddeeh]

Would @Robert know more about diptrace? I think i do remember chatting about diptrace a while ago with him.

 

[Robert]

Like @bean said, my grounds are all attached to the ground pour (top and bottom) unless there is a good reason not to. (LFOs, digital, PWM, etc)

I've never needed to isolate grounds in a gain pedal.

In DipTrace you can either manually draw multiple ground pour shapes (you can't let it automatically fit to the board outline) or you can use the shape/line tool on the Route Keepout layer to carve out parts of the copper pour.

See this post for an example:

Post in thread 'Bring out yer Diptrace'

Nov 13, 2024

If you're willing to share (and I understand if you aren't), are you also isolating the copper pour on the back of the board like you did on the front? How did you handle joining the ground and power planes?

Oh absolutely, there's no top secret proprietary information here.

The ground plane is split on the back similar to the front, except the split doesn't go all the way to the edge on one side so it creates a thin trace running up to the top of the PCB.



The Double Pendulum is isolated as well but instead of splitting the PCB in half I just fenced off the LFO...

• Robert

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