DAC TDA1541A : routing issue

[ZERS]

Hi,

going further with my DIY CDPLAYER, I've completed most of the schematics and the boards (DAC, PSUS).

The CDPLAYER will be based on the CDPRO2 drive and the dac is using 2 TDA14541A in //, the output buffer using 2 6C45PI tubes.

I decided to use a ground plan for this DAC, thus avoiding me to search for ages the best connection between both analog and digital grounds

Unfortunatly, I'm facing up an issue with this ground plane. A small part of it is "isolated", meaning that this part is not connected to the main one.


On the board, you could see this part : this is the one where C2_21, ...C2_19, C2_VDD2 are connected to.

You will see as well that I have added a short route on the top layer (in RED) between C1_10 and and C2_19 to link the isolated ground to the main one.
But I don't want to make a 2 layers board. I was previously thinking of replacing those TOP routes by Wires soldered point to point.

I guess It would'nt be a big issue for 2 of them (-15V & OUT_Left routes) but for the link between the 2 ground planes, I'm not sure that It won't cause any oscillation or other issue.

As I could not post the schematic and the board here (they are too bigs even when zipped ), you could find them here (in a french forum sorry ) : DAC SCHEMATIC AND BOARD

The DAC.ZIP file contains the schematic and a old version of the board, please look into the CARTEDAC.JPG file attached below to have the newest one.

What do you think about connecting with a wire ? Do I try to avoid it ?

Anway, feel free to comment the schematic and the rest of the board if you find something wrong

Thanks in advance

[jean-paul]

Hello Zers, I think the advantages* of using parallel DACs will weigh up against the layout problem. Optimising the layout for 1 chip will be difficult enough but easier than with 2 chips... As I checked the layout I got the idea the questions you pose will not arise as much when using 1 chip, which is a big plus.

* paralleling sounds worse in my ears, did you breadboard this paralleled DAC and did you listen to it ?

Your PCB-design will definitely benefit from designing it double sided ( especially the ground plane ). Why not go for the best while you're working at it and put all your time in it anyway ?[

[ZERS]

paralleling sounds worse in my ears, did you breadboard this paralleled DAC and did you listen to it ?

I did obvioulsy, but I didn't compare to a single DAC . The sound seems to me really good.

Your PCB-design will definitely benefit from designing it double sided ( especially the ground plane ). Why not go for the best while you're working at it and put all your time in it anyway ?[

Because it's gonna be hard to find a manufacturer that could build the double side board for a good price.

But I'm open minded

[TDA1540]

[QUOTE]Because it's gonna be hard to find a manufacturer that could build the double side board for a good price. [/QUOTE

with one side used as a groundplane ,it is essentially a singlesided pcb you want to make.