[sdiy] PCB op-amp layout - 2x2 or 1x4

[David G Dixon]

>> I don't get the issue with the power being on the "wrong side" as these
chips are symmetrical, one could just turn it around and have the power pins
facing the "right direction."  What I do worry about is interaction between
opamps in the same package.  Depending on what you're doing it may indeed be
better to use a few duals rather than quads.  In the real world, isolation
between Opamps in the same package can be less ideal than the specs say.

The quad power pin thing is an annoyance, but a bloody needless one.  Why
did they do it that way?  It just means all the quads need to be installed
upside-down.

The isolation thing is true.  "Crosstalk attenuation" for TL07X is rated at
120dB.  It ain't!  At least not at 2000 Hz.  120dB should be dead silence.
However, high-pitched squeals will happily slip from one opamp to another in
a TL074.