Doepfer

Hi Timothy thanks for the information.

I have the A190's midi thru jack wired internally to the 
A191's midi in jack with two short lengths of wire. That's been 
working fine for a couple of years.

So now I'm thinking that if I connect a cable from a rear-panel DIN 
socket to the terminals on the A190's midi in jack, whatever opti-iso 
stuff is going on should be preserved. Do you think?

Joe

--- In Doepfer_a100@yahoogroups.com, "Tim Stinchcombe" <timothy@t...> 
wrote:
> Hi Joe,
> 
> > Speaking of connectors in the back, if I were to install a DIN 
> socket 
> > in back of an A100 frame and wire the midi signal internally to 
the 
> > A190 and A191, would simple wire work OK? Shielded two-conductor? 
> Thin 
> > coax?
> 
> The simple introductory book I have on MIDI says that screened twin 
> core cable of audio quality is fine. BUT, MIDI is not 
> straightforward. It works off a 'current loop', with opto-isolators 
> used to ensure that interconnected bits of kit are electrically 
> isolated from one another. The book strongly advises against trying 
> to drive two inputs from a single output (you wouldn't be able to 
> guarantee that either input would work properly) - this means that 
> you would still have to run your A-191 from the 'thru' of the A-190 
> (although conceivably you could connect them internally). Also the 
> point of using screened cable is to prevent interference 
> from 'escaping' from the lead, and not from noise penetrating it - 
> the screen on a lead is attached to both pin 2's at either end, but 
> the pin 2 on any socket is *not* connected to the chassis, in order 
> to maintain the isolation of all bits of kit.
> 
> I'm not sure how helpful the above is - you were obviously expecting 
 
> to connect things internally, only it might be less simple than you 
> had imagined (?).
> 
> Tim