Archive of the former Yahoo!Groups mailing list: MOTM

I was studying the minutiae of the MOTM-101 schematic (yes, I'm an
insomniac) and I noticed that there are two "C25"s on page 2. I imagine that
the one marked "10M" hanging off U8A is the correct one, so what is that
0.1M C25 bridging ground and the +15 rail up at the top of the page...? I
can't seem to identify it by comparing the board to the schematic.

(I'm guessing that the numbering is a quirk of the 100/101 revision.)


Whil I'm at it, there are a few questions that have been nagging me for a
while... now's as good a time as any to raise my hand and show my
ignorance...

What ∗are∗ those little 'floating' schematic pieces? In the case of those
floaters in the '101 schematic, are those caps between the rails and ground
"decoupling capacitors"? Put there to absorb fluctuations in current? Why
aren't they shown where they actually connect in the schematic?

Also, unused portions of op-amps tend to be shown "floating" around, too,
and connected in weird ways, such as the output connected back to the input.
Is there a reason for that?

Had to ask!! :)