[sdiy] MIDI on Cat6

[Ove Ridé]

It should work. The very reason the pair are twisted is to reduce
interference. Since the two wires switch side every x mm, the net
magnetic field is zero. Also note that each of the 4 pairs have
different twist rates, ie the length of each rotation is different
between the pairs. This again is to reduce interference between the
pairs in a single cable. Using the various pairs in a cable for
different MIDI should be not only possible but the recommended
solution in my opinion. Or otherwise, I would probably hook up +5V and
the MIDI signal (pins 4 and 5) to one pair for maximum data integrity
when used as MIDI, and then use each of the other pairs (ie both wires
in the pair) for each of the remaining signals.

What you should keep in mind is that any signal going on pin 4 will
induce a small negative copy of itself on pin 5 due to the twisting of
the wires and vice versa. This is intentional in ethernet's
differential pair signaling and causes constructive interference of
the signal. This is not a problem for MIDI. This is also not at all a
problem for DIN sync since it's using mostly pins 1, 2 and 3 and
usually at most only of pins 4 and 5. But just something I thought I'd
point as a disclaimer for my proposed solution.


On 19 September 2016 at 20:23, Dave Magnuson <abide at dmdrafting.com> wrote:
> Hi All,
>
>
>
> I’m wiring up some wall jacks in my studio so I can MIDI and audio from one
> side of the room to the other without a bunch of cables lying on the floor
>
>
>
> My question is:   Do you think it’s safe to use Cat6 cable for MIDI?  Cat6
> itself isn’t shielded, but it will be routed entirely in metallic tubing and
> metal boxes, all of which will be grounded.    Do you think there would be a
> high likelihood of cross-talk between twisted pairs within the Cat6 cable
> itself?
>
>
>
> The runs are about 20 feet (3 meters) with 2 sets of MIDI cables per
> conduit.  I will likely wire up all 5 conductors on each end so I can use it
> for din sync, too.  I’m not so concerned about MIDI bleeding into the audio
> because they run in separate metal conduits, and likewise with nearby power
> wiring.
>
>
>
> Anyone ever tried something similar?   If I had star quad I’d just use that,
> but would prefer not to buy a spool if I don’t need to.
>
>
>
> Thanks!
>
>
>
> Dave Magnuson
>
>
>
>
>
>
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-- 
/Ove

Blog: <http://blog.gg8.se/>

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