Not in fact. There’s only one layer (n°2) dedicated to ground where PSU ground (capacitors) and audio ground (signal In / pot. ground / OPA non inverting input) are connected together. Then I connect one pin (R99) to the filled cooper zone so to connect the board ground to the PSU ground… I hope it’s clear.
BTW is the filled cooper zone a real layer of cooper ? (very very thin I guess)
And , as I said at the beginning of my post, some pins refuse to connect to where I’d like to, that’s why I added resistors 0Ω value so to connect my wires
Filled copper zones you place at the same layers as tracks. Tracks and copper zones at the same layer have the same thickness as they come from the same source copper foil.
At typical 2 layer board copper layers have thickness of about 35um.
I’m not 100% of 4 layers, but suppose inner layers are 18um.
These made me thinking that you may be don’t have a schematic. KiCad should allow you to connect everything that according to schematic belongs to the same net. If KiCad has something against you doing connections than you probably try to connect together copper belonging to different nets.
It seems that Kicad refuses to connect a stand-alone pin (SolderWire-0.1sqmm_1x01_D0.4mm_OD1mm for ex.) to a pin already connected to something by a track : the soft proposes me to connect my pin to free pins only…
For example I wanted to connect a vias to OPA pin 5 but it refuses and I had to add a R (R98) to connect my wire (audio signal input)
no… that would be the reason ??? Damn, why can’t we just connect what we want in the PCB editor ? So and what about vias ? Aren’t they supposed to connect anywhere you decide to in PCB editor ?
If you bypass the protection by connecting points that are not connected in the schematic then you can introduce errors in the circuit. That’s not the way to create correct, reproducible circuit boards.
Vias are not specified in the schematic at all but like tracks they have to connect points that are connected in the schematic.
Thank you !!! I will try to generate connecting points in the schem. editor…
Could you please tell me the name and the “family” (connector ?) where to find a simple “hole” with cooper on top & bottom layers where I can solder a wire ?
You can hand edit pads in the footprints on the PCB one by one, and then select a net. It’s tedious, but that’s also good, as it’s generally a bad way to do things. The normal workflow is to first fix the schematic, then port the netlist to the PCB editor, and do your thing over there.
KiCad’s support for the reverse workflow is also slowly improving. You can:
Add some schematic symbols, assign footprints. (No wires nor labels yet).
Put the footprints on the PCB (This is still normal “forward” workflow)
Draw tracks from sum as of yet unassigned pads.
Give that net a name (you can enter and create a new net name from the search box).
PCB Editor / Tools / Update Schematic from PCB, and update the net names. This creates labels directly on pins in the schematic, or on the wires if there already are wires.
This workflow is useful for reverse engineering a PCB for which a schematic is not available yet.
Yes a generic 1 pin connector would work. But shouldn’t you consider the audio signal as a pair of wires, i.e. signal and ground, and use a 2 pin connector? Similarly for the balanced power supply that could be a 3 pin connection.
Yes I could but the way the board is arranged it would mean some “travelling tracks” across the board… I don’t mind soldering stand-alone wires.
In the last PCB schematic I connected all pins in “F.Cu + B.Cu + all connected wires” mode and set the pads connection to “thermal relief” with 0.5 spoke and 0.5 gap : is it correct knowing that I will solder all thru-hole components myself ?
About the pin J7 (which is the main GND) I set it to “all copper layers” so it’s the only one connected to the cooper filled zone.
Does this board’s arrangement look like a mess or is it acceptable ? Its dimensions are 75mmx54mm
Normally the big copper zone at the bottom is connected to GND. This helps a lot for reducing EMI. This is probably not such a big issue in audio, but it also reduces noise and hum pickup. (Very) maybe it make some sense to not use a GND plane at all for audio, to reduce capacitive coupling, but it also depends on other things, such as whether you put this PCB in a metal box.
But whichever way you go, Cutting a big “GND”? plane apart by routing long tracks through it is a very big beginners mistake.
I should place the filled cooper zone at bottom layer ? Is there a way to change layers’ order ? Exchange layer 2 (GND) with layer 4 (Vee) ? But in that case the “F.Cu, B.Cu and connected tracks” which I need to solder my components on bottom layer will connect all components to GND ???
Sould I delete the GND tracks and connect each concerned pad to the cooper filled zone ?
To be honest, I’d happily make this a 2-layer board with a GND plane as the back layer and route both signal and the two voltage rails on the front layer. Your power supplies do not need a whole layer each, current draw is small. I would just make power tracks wider.
0.5 wide for power tracks ? (as I did for ground tracks)
are the thermal relief for all pads set to 0.5 spoke and 0.5 gap ok ?
Audio and power tracks on the same layer means some arrangement because you can see some tracks crossing (which is very practical). The price does not change so much between 2 or 4 layers so if there’s no “technical” reasons to change I’d like to stay as it is…
I repeat my question : should I delete all ground tracks and connect the concerned pads directly to the cooper filled zone ?
You don’t need to. When you do the fill, it will overlay the ground tracks where they overlap as they are on the same net. So just route as normal and then do the fill.
Using vias and a few “jumper” tracks on the ground plane is ok. Or you could use an inner layer for the crossovers, leaving the back layer for GND.
So now, except the fact that you would make this board with 2 layers only, do you think it can be sent to a PCB maker ? The DRC test shows no error. And I set the power tracks to 0.5
Or someone could maybe have a look at the Kicad file ?
that would be the reason ??? Damn, why can’t we just connect what we want in the PCB editor ? So and what about vias ? Aren’t they supposed to connect anywhere you decide to in PCB editor ?
