> Thanks Dieter.
>
> I have yet to locate any in small quantities for sale in the US.
>
> I wonder whether one can make a temporary substitute with a standard
> jack socket or does one need all 4 contacts.
>
> TD

That depends upon the module and the in/output in question. In ~90% of all
cases only two terminals are actually used (GND and tip). But if the socket
has a switching contact the terminal of the switched tip has to be wired
too.

Best wishes
Dieter Doepfer