Pearl layout - how to organise things to avoid noise

[cviller]

I'm drawing a new layout for pearl because I have some slightly different parts and I enjoy the process of reading a schematic, make the layout and etch it my self.
But since I am redoing it completely, I am trying to figure out if I should change the layout slightly.

The input section is according to the article and threads very sensitive to noise. If the two boards are in the same case, the input of one of the channels will be very close to the output and voltage regulater of the other - is that a problem? Would it be a good idea mirror the channels so the two input sections can be together or far apart?

I'm making it for someone I know and I think he will prefer, if he doesn't have to split two many cables, so Right and Left should be placed close to each other for input and output if possible.

I have made some suggestions and attached primitive sketches. What do you guys think, should I try something new or try to get as close as possible to Waynes layout?

[cviller]

I forgot to explain my sketch. The gray circles indicate the input section, where noise should be minimal and the black circles are the capacitors for psu and where regulation will be placed. Right and left are indicated by red and black wires.

[steenoe]

Hi cviller. Alternative C on your drawing looks like a good bet.
With the boards placed in one side of the case you can run the supply leads in the opposite side, maximizing the distance between signals and supply leads. That said, my Pearl is in the same case as the trafo at the moment and its pretty silent.

Steen

[cviller]

Hi Steen,
Thank you for your comments. It is also the configuration I prefer.

I haven't started layout yet, but I think I'll start soon, because I have most of the components already.


Another thing I need to decide is whether I should go for single or double sided layout. I guess it should be possible to make it single sided - on the pics from the article it looks like there are only very few traces on topside. It looks like fat ground traces - is it?
Our friends at diyzone appear to be making a kit with groundplane on top:
http://www.diyzone.net/article.php?sid=639

Does that even make any difference? Does it shield the signal traces against radiation from the components? I thought groundplanes were more useful in RF circuits...

[steenoe]

Yes, the topside is a groundplane with a few traces that, as far as I can recall, are groundtraces allright . Its easy enough to use a groundplane, only trouble (if making the boards yourself), is to remove the copper where the components are placed. The circuit might be simple enough for a singlesided layout, and should be doable without the groundplane also.
If you look at the online version (not the pdf) on Passdiy, there is some nice high resolution pic's.
http://www.passdiy.com/projects/pearlono4.htm
Try to click on fig. 7 Looking forward to see your results.

Steen

[cviller]

Hi

I don't know if this is a good idea, but I'm posting a very early draft of my layout.
I still need to clean up, make it a bit shorter and make some of the traces wider. I have decided to fill as much as possible with ground.

Comments are most welcome, but please remember that this is just a draft I made last night.

I'll post my schem too.

[cviller]

... and here it is:

[steenoe]

Cool idea to replace the SK389 with SK170's. Those SK389 are pretty hard to find. Nice work on that board

Steen

[cviller]

Originally posted by steenoe
Cool idea to replace the SK389 with SK170's. Those SK389 are pretty hard to find.

That is exactly why I did it, but I'm not completely sure how much I need to match them.

I have cleaned up the board so it should fit on a 180x80 mm board.

Any comments to my layout?

[cviller]

I have a version with better resolution here:

http://viller.org/audio/pearlpcb.pdf