28-01-2016, 10:35 AM
(28-01-2016, 07:45 AM)ppppenguin Wrote: Most of the design "magic" was in the physical layout and PCB layer structure.
Ain't that the truth
In audio power amplifiers, PCB layout can change the distortion by several orders of magnitude. Like, 0.003% vs 3%. And crosstalk is primarily a function of layout. Too many start out assuming that PCB tracks are zero ohms. And when they realise that's not true, they try to make them zero ohms! Doesn't matter how much you "beef up" the tracks; if the layout is wrong, the circuit won't perform correctly. Even ground planes aren't enough in most cases. Eventually people figure out how to "see" where the current flows and use correct noding, but a lot of commercial designs still get it wrong today. The difficulty with audio is the dynamic range - 0.003% is 90dB
This is one of favourite free resources: http://www.ti.com/sc/docs/apps/msp/journ...aug_09.pdf
We still have some of those Quartz routers at work. When we eventually decide to bin them, I'll think of the museum - but as you've already said, control is the issue. Perhaps now is the time to learn about PICs or Arduinos
