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Re: Newbie question: PS caps close to output transistors

Posted by Jacques on February 13, 2005 at 07:52:22:
>This might be totally wrong,
It is not
> but since putting small caps right next to opamps (often on the pins) seems
> to be very good,
It does not seem, it is. With modern opamps such as OPA134 and the like, you should use SMD mounted less than 3 or 4 mm away from the chip.
>how about putting small caps close to the output transistors in a power amp?
You shall also. But the ground connection from this decoupling caps shall be routed by its OWN WIRE, with nothing else connected to it, down to the central ground star. Using it for other ground routing is an excellent way to make your PA a power oscillator until it smokes dead. Not doing it is anolther excellent way to get a power oscillator, which will oscillate only on some loads of for some output power, or for some temperature...
So, I don't say "you should" but "you shall". Just do it the right way.