extending MIDI cables???

[Andi Rauscher]

Hi all!

for a live recording I would like to not only record the audio of the Keyboards, but also the MIDI. (to have a MIDI Track in Pro Tools, for later editing etc...).
Now, my question:

Can MIDI be extended?

for example, can I make myself an adaptor from MIDI to XLR and back, and send it like the audio over the multicore??? Or do I need some kind of DI Box for MIDI??? does such a thing exist?
I don´t think I am the first with this idea, so I thought I´ll see what other people think about this.
also, is MIDI a digital or analog signal???

Thanks, Andi

[djinnocyde]

yeah, what youre looking for is a ID-10-T cable or you can opt for a a 2 channel converter to get a stereo signal. I think hosa makes one for about 40 bucks.
it only transmits @ 16 bit though , but when youre going from midi to xlr, theres no other way to do it.

hope this helps.
db

[SparkyCanada]

Hey there.

Yup - you sure can run midi along an xlr cable - I use this concept everytime I do a gig where I haul my midi rig out.

I had a local tech here make me some midi adaptors that I can plug into any xlr cable.

I think he found the pin configuration on the net somewhere.


SparkyCanada

[max cooper]

I used some solid-core CAT-5 cable to make a 100' midi cable and it works fine; I would think it depends on the sending and the receiving device, though.

I know very little about midi, but since I was making a five-pin to five-pin, I connected one to one, two to two, etc.

Here's the pinout:

http://www.bnoack.com/index.html?htt...di-pinout.html

Seems I didn't need pins one and three to be connected.

So according to this, it looks like it would help to have four and five connected to a twisted pair (thanx to opentune for the idea) and pin two to the shield in order to run the stuff the farthest.

The solid core CAT 5 is really easy to terminate to the DIN connector; if you're trying to stuff a multi-core in there, you'll probably melt a few of the plastic insulators that hold the pins before you get one good clean one. But the solid-core just pops right in.

[max cooper]

Originally Posted by SparkyCanada

I had a local tech here make me some midi adaptors that I can plug into any xlr cable.

I'd say you need two adapters for each midi run. One to go MIDI to XLR and one to go XLR to MIDI. (But if you're gonna go to all that trouble, why not just make a super long set of MIDI cables, unless you're gonna run it thru the snake?)

At the front end, you need a 5-pin DIN (180) and a male XLR and at the other end a female XLR to a 5-pin DIN.

I'd connect DIN pin 2 to XLR pin 1,
DIN pin 4 to XLR pin 2
and DIN pin 5 to XLR pin 3

Anyone think of a better arrangement?

[Albert]

http://www.cablesnmor.com/keyboard-extension-cable.html

I forget what the maximum recommended cable lenght is for midi, 50 feet comes to mind. Although longer runs could depend on your equipment. It's probably a trial and error thing when you get runs that long.

Also, I have heard of midi cable extenders, powered boxes that allow super long cable runs.

[SparkyCanada]

I'd say you need two adapters for each midi run. One to go MIDI to XLR and one to go XLR to MIDI. (But if you're gonna go to all that trouble, why not just make a super long set of MIDI cables, unless you're gonna run it thru the snake?)

Max Cooper - you are correct - 1 adaptor for each end - you end up with midi to male xlr & midi to female xlr.

The reason I chose to make adaptors for xlr cables was so I didn't have to make a dedicated long midi cable. If a cable starts giving me grief - I unplug the adaptors from the cable - and re-attach them to another mic cable - and away I go...

SparkyCanada

[triez]

The MIDI specification is max. 50 feet. It is a 5V current loop driving an optocoupler at the receiving end, ie: it is simply flashing an LED in front of a phototransistor.

It is a 2 wire circuit, usually the ground at pin 2 is connected in MIDI cables (Pin 2 is the centre pin, they count the pins in an odd fashion on a DIN connector), and this ground is not necessary.

Here is a tip.... the unnecessary ground can cause earth hums with keyboards, so if you are in the studio and you have a mysterious hum when you patch the keyboards up, try snapping off the center pin of your MIDI cables at one end, thus breaking the eath loop.

You can run MIDI through ant reasonable quality cable and connector combination.

[max cooper]

So if it's attached to the shield but not connected at one end, it's a telescoping shield, right?

[triez]

Originally Posted by max cooper

So if it's attached to the shield but not connected at one end, it's a telescoping shield, right?

Yes, same as when you only earth one end of a balanced audio connection in the studio.
MIDI is very robust, so on short runs or around the studio it is much less prone to noise pickup than audio, so the earth is irrelevent. In a long run in a stage environment it would be best to shield it though.