Want to build a TDA2040 amp.

[delus]

Looking forward to seeing your progress.  Are you making your own PCBs?

I haven't made any yet, but I will be making my own from now on. I'm currently designing the layouts to be trasfered. As soon as I get the hang of it, I will procced with this project. It may take some time though because spare time is limitied due to work and stuff. But, as I said on previous post, I will report with my progress ASAP.

Cheers!

[delus]

I think it's time to report my progress so far; I have made a layout for the power supply based on the schematic i have previously posted.
Below are two versions, the differences between the two are the ground and the pilot light. The first version has a common ground and a low voltage pilot light. The second version has seperate grounds for the power amp's and the preamp's power supply (which will eventually meet at some point I guess) and a no pilot light on the board. I think I'll go with the 2nd version and use a 230V pilot light but there is still though some studying to be done on grounding before the actual realization.

So here it is...

Note (Sept 12 2011) that after following J M Fahey's suggestions below, I edited the post leaving only one version which I think is best.

[J M Fahey]

So far so good, but I'd love to add something:
it's publicly known I'm not a great fan of Eagle (to put it mildly).
One of the many things I don't like, and which I find downright dangerous is the impossibly small pad size they use as default.
Fact is, PCB software compete with each other by stating something like "I can poass 3 tracks between a resistor's pads" , to which other one counteracts with "I can pass 5" , and so on.
Silly !!!!!!
It's a plain and simple geometry problem, the only way to do so is to specify silly small pads and hairline tracks.
Fine for a low power high density video board or whatever, but a disaster in the Guitar Universe.
Use at least 85 mil pads, even better 100 mil ones, and at least 40 mil tracks, no less than 30 mil and that only in cramped spaces, for a couple inches.
In principle turn auto fill or ground flooding off, it only adds an illusion of a beefy PCB while actual tracks are skimpy.
It's much better to thicken traces after the design is finished, and adding "by hand" generous ground copper areas.
I'll post one of my actual, commercially sold PCB designs as an example of real world surviving ones.
Not surprisingly, quite similat to what, say, Laney uses.
Peaveys are usually excellent: modern Fenders not much so, Marshalls (Valvestate and such) are quite unreliable.
They often crack at the pad to track union, with a hairline separation which drives you crazy.
They are often (incorrectly) referred to as "cold solder" because usually resoldering that pad bridges the gap and you restore the connection.

[delus]

I had already fattened the large capacitors' pads to 124 mil and used 40 mil tracks at the power amp's supply! But I will follow your advice for the rest of the components as well. It is kind of annoying that you have to manually modify each components pad dimension, but once I make a full modified library, it wont be necessary again.

Thank you very much for the advice.
Offtopic question: Do you think it's necessarry to use these sizes for pedals also? I'm currently using 24 mil tracks, 50 mil pads, and 22 mil clearence.

[J M Fahey]

Minimum practical  pad size *for us* is 65 mil , remember the hole will be no less than 25 mil and probably more; we must also allow for slight off-center error.
I find 30 mil tracks very easy to iron or silkscreen; any thinner *can* work but on expensive photopositive bords.
Excellent but too expensive for my regular work.
I only use them in, say, guitar preamps (they may pay in pedals too) because they are stamp size , at most visit card size.
But in a long preamp or a power amp .... no no baby.
Now, in a very tight place you may go down to, say, 20 mils (even 15 in an emergency) but only for, say, one inch or less, whatever's necessary to pass between a couple close  pads.