I looked into this, but it seems a little advanced for me, I'm still not sure how many watts I need for a stereo and how many for a horn so I'll have to do some experimentation. Once I know what I need I might be able to find something that would work, but I don't think I'd be able to figure out if it is efficient or be able to improve it if it wasn't.
In the mean time, I've got a 3W amplifier circuit I found on ebay and I'm working on a 15W version based on an app note
I find it curious the way they've separated out how the left and right are connected to power and ground, does this indicate that they should be physically separated somehow? or just showing what those capacitors are there for?
I captured it in a similar way on my schematic, but I realize during layout that it's not going to make a difference. I'm thinking that there is something to this that I'm just supposed to know, but don't.