MIDI cable pinout

[C3]

Hello,

I want to build an extended length MIDI cable that goes from the 5 pin DIN
connector to the 15 pin D-Sub 15 connector on my sound card. I know that
this is not a straight pin-pin cable and I'll have to build a circuit.

Does anybody know where I can find the schematic, or how hard it is to
build? Would I be better off by modifying my current (but short) MIDI cable
and extending the wires? How strict are the MIDI timing requirements?


cheers,

C3

 

[Grog]

"C3" <user@host.com> wrote in message
news:3fc33c7e$0$20395$afc38c87@news.optusnet.com.au...

Hello,

I want to build an extended length MIDI cable that goes from the 5 pin DIN
connector to the 15 pin D-Sub 15 connector on my sound card. I know that
this is not a straight pin-pin cable and I'll have to build a circuit.

Does anybody know where I can find the schematic, or how hard it is to
build? Would I be better off by modifying my current (but short) MIDI
cable
and extending the wires? How strict are the MIDI timing requirements?

Have a look here: http://www.harmony-central.com/MIDI/interface.html
It would also seem that the MIDI spec calls for 15M (50ft) max length.

HTHs
Greg the Grog

 

[Clifford Heath]

C3 wrote:

I want to build an extended length MIDI cable that goes from the 5 pin DIN
connector to the 15 pin D-Sub 15 connector on my sound card.

I've done it the hard way, and would have been best to get one of the
"MIDI breakout box" kits (available from Jaycar or DSE). Your 15-pin
connector carried a 5V TTL-level version of the MIDI signals, which
need to be opto-isolated current loop. You can't use the cheapest
available opto isolators either, as they aren't fast enough - 6N35 is
a common type for MIDI. You should be able to run a long cable however,
as current loop is pretty good against interference.

 

[C3]

I've found some schematics online, and most of them use the 6N138. What is
the difference between these, and how much should I expect to pay for one?

cheers,

C3

6N35 is
a common type for MIDI. You should be able to run a long cable however,
as current loop is pretty good against interference.

 

[Clifford Heath]

C3 wrote:

I've found some schematics online, and most of them use the 6N138.

That'll be it, sorry the memory was rusty. About $6 IIRC, silly price.
Haven't done MIDI for a few years - I built a MIDI percussion controller,
64 channels, for a vibraphone, using a 68HC11.

 

[C3]

About $6 IIRC, silly price.

Hey, it beats the fifty odd dollars Allen's Music want for a 1m MIDI cable.
I need a five metre cable, imagine how much they charge for that.

Haven't done MIDI for a few years - I built a MIDI percussion controller,
64 channels, for a vibraphone, using a 68HC11.

I learnt how to program the HC11 at Uni (only last year, actually). I hope
your program worked ok.


cya,

C3