> Looking around, it seems a lot of systems contain the "multiple"
> module in at least pairs or more. What do these do for me I'm a
> little unclear.

Some examples:

LFO modulation to two or more VCOs for vibrato.
A190 Clock and Reset signals to both A155 sequencer and Clock Divider
Audio signal to two parallel filters
Filter output to two VCAs for stereo panning.
A141 ADSR output (there's only one, unlike the A140) to two or more
destinations.

BAD example:

Pitch CV to two or more VCOs. Use the system bus for this instead, or
you'll get a voltage drop resulting in the synth being out of tune.

> Also, given that I have an A190 MIDI/CV in my mini, how can I use
> this to also drive the modules I'll be adding to the G6 rack
> Do I need one of those buss breakout modules or two

The easiest way would be to move the modules around so that the A190,
the VCOs, and the ADSRs are all in the same frame. If it's the 6U
frame, buy one of those bus connectors (A-100 BC) to internally
connect the upper and lower bus bars.

If you want to connect the bus in the 3U frame to the bus in the 6U
frame, then you need TWO of the A185 bus access modules, one in the
sending (A190) and one in the receiving frame.

In my four-row system, I have a single A185 in the 6U frame that
contains the VCOs and the ADSRs. I patch CV/Gate in to this from
either the A190 (bus connection cut), the A155/A156, or from an
external source. This solved all my tuning problems.

> I am planning my G6 rack to be mostly pairs of filters, oscillators
> and VCA's plus the 4x mixer and perhaps an LFO or two.
> What else should I look for

I would put the ADSRs in the 6U frame also, so that they're on the
same system bus as the VCOs.

Joe