WillStG wrote:

I would like to record the voltages passing between say, one of the Calrec's
faders and a ground point for a month and see it we get any spikes, and record
the time, duration and voltage of any events. I would like to record and
quantify this mystery.

Chart recorders are the old traditional way of doing this, but you will find
a lot of the power loggers will let you measure DC voltages as well over the
long term. The Fluke power loggers are probably rentable from some place
like Tucker that rents test equipment. Astro-Med makes some loggers that
pretend to be chart recorders with LCD displays.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."