[sdiy] Hey all: first post

[Jesse Yoder]

Hey all.  This is my first post on this thread.  I subscribed the
other day and have been enjoying just lurking and reading the
messages.  I have been doing electronics as a hobby for at leat nearly
10yrs now, and while I'm not an EE, I have done my share of building
projects.  I am currently putting together plans for a modular
analogue synth using other peoples schematics and I have what may be
considered a stupid question.

In many schematics I have looked at, the inputs and outputs of each
module are shown as simply one wire in/out.  I had been unsure, but
had decided that it must be implied that the other node of the jack
would go to the common gorund.

However, I have been doing some digging and have noticed people using
banana plugs rather than phone jacks to connect some modules; also, I
have noticed designs which seem (at least to me, with my limited
electronics expertise) to not make sense to complete the circuit with
a jack connected to common ground.  So my "stupid" question is this:
in the following schematics (and in modular analogue synths in
general) are phone plugs using only one wire, or am I supposed to
connect the jacks to common ground?

Some schematics I've been looking at:
http://www.musicfromouterspace.com/analogsynth/keybrdcontroller.html
(no jacks, and no explanation of whether the jacks should be
"grounded")
http://musicfromouterspace.com/analogsynth/norgate_adsr_001.html
(another schematic from the same site, with jacks inserted and
grounded)
http://www.abacom.com/~ivanohe/synth/ivanohe1e.html (A guy using
banana plugs [those have only one wire, am I correct?])
http://www.sowa.synth.net/modular/vco4m.gif (a schematic with jacks -
implied that they should be "grounded")
http://hem.bredband.net/bersyn/VCO/VCO%20Buchla%20core.gif (no jacks at all ...)

You get the idea.

Hope someone can help.
thanks in advance
~~Ponyboy