dirtyhanfri
Well-known member
Hi
I'm finishing the design of a PCB for a project involving more than a pair of inputs and outputs, not a big mixer, but 6 Line input and 6 Output circuits and some relays, I'm working in a 2 layer design, and have some doubts about grounding.
I know this have been covered many times, and I applied many tips read here, but I'd like to check if I'm misunderstanding something...
There will be 2 psus, one for +/-24 and one for +/-18 both with their 0V connected together to the chassis. That will be the "main chassis point" also I'll connect there 0V from the main board, I'm doubting if run each xlr to it or connect them to the chassis in their mounting screw, maybe I should connect them trough their mounting screw and also daisy-chain every xlr in a wire going to "main chassis point"?
In the main board, where the audio circuits will be, I have separated ground for every audio circuit block, I've drawn traces for GND and then outlined a zone surrounding the circuit which is copper filled, every circuit block has it's ground isolated from other circuits, they connect to the chassis via xlr's. Is this OK or should I connect every ground plane via a single wide trace? Or just connect the input circuit to it's associated output circuit and so?
For the relays, (fed by the +24V PSU) I've drawn traces for each 0V, joining together to make a wider trace which ends in a little plane where I'll put a Faston connector or whatever to run a thick wire to that chassis point mentioned earlier. Right?
My main concern is about the opamp decoupling caps (all of them running from the +/-18V PSU) should I connect their 0V leg to the audio GND? I have it this way right now, but I could make a copper plane for them and join it to the 0V of the+/-18V PSU/Chassis. What will be better in noise terms?
Thanks in advance
I'm finishing the design of a PCB for a project involving more than a pair of inputs and outputs, not a big mixer, but 6 Line input and 6 Output circuits and some relays, I'm working in a 2 layer design, and have some doubts about grounding.
I know this have been covered many times, and I applied many tips read here, but I'd like to check if I'm misunderstanding something...
There will be 2 psus, one for +/-24 and one for +/-18 both with their 0V connected together to the chassis. That will be the "main chassis point" also I'll connect there 0V from the main board, I'm doubting if run each xlr to it or connect them to the chassis in their mounting screw, maybe I should connect them trough their mounting screw and also daisy-chain every xlr in a wire going to "main chassis point"?
In the main board, where the audio circuits will be, I have separated ground for every audio circuit block, I've drawn traces for GND and then outlined a zone surrounding the circuit which is copper filled, every circuit block has it's ground isolated from other circuits, they connect to the chassis via xlr's. Is this OK or should I connect every ground plane via a single wide trace? Or just connect the input circuit to it's associated output circuit and so?
For the relays, (fed by the +24V PSU) I've drawn traces for each 0V, joining together to make a wider trace which ends in a little plane where I'll put a Faston connector or whatever to run a thick wire to that chassis point mentioned earlier. Right?
My main concern is about the opamp decoupling caps (all of them running from the +/-18V PSU) should I connect their 0V leg to the audio GND? I have it this way right now, but I could make a copper plane for them and join it to the 0V of the+/-18V PSU/Chassis. What will be better in noise terms?
Thanks in advance