> I was looking at the pdf about connecting an A-143-9 to an A-126
> http://www.doepfer.de/a100_man/A126_A143_9_connection.pdf
>
> I see a 10uF cap on each connection on the diagram but the text
> doesn't mention adding one. Should one be added to each connection

Yes, as the diagram says.

> Also is the signal out from the jumper pins on the A-143-9 any different

than the hot signal

> out of the jacks on the module front What I'm looking to do is put a DIY

expansion panel

> next to the A-126 with normalizing jacks and optionally connect some

quadrature CV sources I have.

I do not recommend that because the internal signals are not buffered or
protected. If you connect the signals to external connectors and make a
short (that happens e.g. when a plug is inserted into the socket) the
circuit may be damaged ! You should at least add a serial 1k protection
resistor into each internal signal path that is connected to an external
jack socket.

Best wishes
Dieter Doepfer