[sdiy] SPICE and Processors

[David G. Dixon]

> Paraphrasing Bob Pease: "It would take you 15 minutes to build that
> circuit. Why bother with simulation?"
> (that was on a seminar I attended in 2005)

I would concur with this outlook.  I basically gave up trying to simulate
audio with SPICE a few months ago.  Usually, just looking at the simulated
waveforms is enough.  I often want to hear how a circuit will sound when a
pot is rotated, and this takes forever in SPICE.

Most analog circuits are easy enough to breadboard.  Since I etch and drill
my own boards, and since most analog circuits are actually easier to lay out
on pcb's than on solderless breadboards, I often just build circuits and do
final testing on the prototype.  I find that it is usually the presence or
value of small capacitors (<1 nF) which must be altered in the final design.
SPICE doesn't always simulate the effects of small capacitors very well, and
their effects are often different on breadboards and pcb's.  It is easy
enough to put extra pads and connections on the board for them.