LM4780 Single side PCB

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This is my first try to make a single side pcb for LM4780.
I'm using the following schematic, (from National website).


I've got no much experience about pcb making, so please make your comments, post your advise, about my pcb.
 
I don't know from personal experience how critical it is but you will notice that National separated the power & output ground plane from the low level signal input ground plane via a 2.7 Ohm resistor. This may help keep noise out of the input.

Also... lead length & width for the high current traces is important. I'd try and add some width to them from the pins to the two big caps. Also... you may want to add some more capacitance. I see your running it in parallel and 2000uF isn't much. National also suggest 10uF OR bigger for the smaller electrolytic bypass. I've only used 10uF with my board (and it works very well) but I plan to experiment with larger values.

I'm not sure how you plan on mounting this to the heatsink but having the one edge of the PCB flush for easy surface mounting makes life a little easier.

Just for space constraints I left the 1.0uF input cap off the board. The good quality MKP caps are large in relation to the board size and I've always just used leaded caps on the input RCAs if DC blocking was needed.
 
PCB - rev 2

And a newer pcb, according to the schematic changes.
Maybe i need more space for the bigger capacitors, but i'll fix that later. Small board is not my first priority, so i'll leave the 1u capacitor onboard. I also changed the width of some power and ground traces.
Kevin, if it's easy to you, why don't you post your pcb?
 

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The 2.7 ohm in series with the output needs to be 2-3W but the other 2.7 ohm resistors can be 1/4W. My board is double sided and I use both sides so it won't do you much good.

Using a MKP 100n cap is probably a good suggestion. It doesn't cost much more than a ceramic but does take up more real estate on the board.

Upupa is correct.... you need to have shunt & feedback grounds separate from power ground also. The grounds from your power supply & the speaker output grounds (along with the zobel ground reference) are all I have on the power ground. All other ground references I have to a singal ground point (star ground) and then I connect the two grounds via the 2.7 ohm resistor (1/4W). My amp is dead quite without any noise on even very efficient speakers when the inputs are shorted.

Spend some time studying the National board. That is what I used as a reference. That and I looked over some of the arguements from the members of this forum to optimize my PCB & ground layout.

Thanks guys!

An externally hosted image should be here but it was not working when we last tested it.
 
This is the newer version of my pcb.
So: R3, C7, C8 (shunt and feedback) and pins 12 & 19 (according to National reference board) to signal ground (star ground)
Grounds from power supply & the speaker output grounds (and zobel ground) are all on the power ground.
The two ground planes are separated with the 2.7Omh (1/4W) resistor.
Tolerance of the two feedback resistors is 0.1%.
As for the two 0.1Ohm/3W resistors i have in mind the VISHAY SFERNICE RPL3.
I'm not very proud about the four jumpers, especially those to the Vee and Vcc lines.
 

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