Creating MIDI to XLR adapters

[hobbsies]

Hi guys,

I frequent the lighting forum, but not so much this one. I was wondering how simple it would be to cut a short XLR cable in half and solder on MIDI connectors to essentially make MIDI adapters to run 100' of MIDI through XLR? Based on what I've found on google, it sounds similar to running DMX through XLR and making 3->5 pin and vice versa dmx adapters, but I can't find any diagrams about which pins to connect? Can anyone help me out? I basically don't want to pay $80 on these: Amazon.com: Mogami 2552 MIDI to XLR Adapter Pair, EHS-Built: Electronics

Thanks so much!

 

[rm2011]

This should help you out. It doesn't really matter which line in the Mic cable you solder to, as long as it's the same on both ends. Just remember midi usually doesn't do well with long runs, so you definitely want to use high quality mic cable. Even then you may still run into some trouble. Good luck. http://www.av-tools.co.uk/pinouts/midi-5-pin#.UbynbqDD8m8

Sent from my Galaxy Nexus using Tapatalk 4 Beta

 

[cpf]

Just google MIDI Pinout and pick the first diagram that you understand?

 

[hobbsies]

Thank you! I've definitely learned about long runs of XLR midi not being the greatest. Caused 6 weeks of headache and 3 different lighting consoles responding differently to the same problem.

 

[hobbsies]

Just google MIDI Pinout and pick the first diagram that you understand?

Ah, I didn't know the terminology to look for, thanks!

 

[themuzicman]

While you can make MIDI to XLR adapters fairly easily, you're not going to be able to reliably transmit MIDI 100' without something like a MIDI Line Driver. Passive XLR to MIDI should only be used for short jumps.

JLCooper MLA-XLR Something like this is what you'd want.

 

[hobbsies]

Hmm, we're using MIDI to fire a few light cues from Qlab to get them properly sync'd. Last year (this show is a remount), we had a solid 100' MIDI cable, but this year I could not find that cable. The year previous, we used MIDI to XLR adapters and ran the MIDI through XLR, but that did cause us a lot of problems that I thought were mostly due to the type of light board we were using. The websites that I found on google talk about making MIDI to XLR adapters so that you can run MIDI through a snake rather than having to re-run a MIDI cable, but don't mention anything about signal loss. While it's not necessarily my goal to send the MIDI through a snake, I just want a cheap and effective way to send MIDI to the light board from Qlab which will be about 75' from the Qlab PC during tech, but only a few feet during the run of the show. What would be your suggestion?

 

[derekleffew]

[Since the topic of this thread is more about interconnection of various disciplines and less about pure audio, moved from Sound to Show Control forum.]

Just a thought...

From http://www.controlbooth.com/forums/...ontrol/26986-midi-vs-rs-232-show-control.html :

But the Express doesn't understand RS-232, or does it?
To overcome cable length limitations with MIDI, use a pair of MIDI line amplifiers.

Back 1000 years ago when Derek and I worked together, I used to recommend them but now I would say just run the MIDI line straight through.

Adding 422 converters (which is what that JL Cooper product [MLA-10] is) adds many additional failure points, additional power supplies, etc. My #2 design principle (after safety) is to keep things simple.

Charlie Richmond has run MIDI, IIRC, about 1000 feet on Cat 5. He has more info here.

John

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... It doesn't really matter which line in the Mic cable you solder to, as long as it's the same on both ends. ...

Now wouldn't one want to have the shield/ground on DIN#2 to XLR#1, and the DIN pins 4&5 to XLR pins 2&3?
The each of the pair doesn't matter provided it's the same on both ends, but, for ease of construction as well as future use, why not be consistent?
-----

... I basically don't want to pay $80 on these: Amazon.com: Mogami 2552 MIDI to XLR Adapter Pair, EHS-Built: Electronics

While $80 does seem excessive, I feel $31.80 (the actual price) is fair, considering the four connectors may cost $15-20 and factoring in labor. Plus I hate soldering DIN connectors, so I'd buy a short MIDI cable, chop that in half, and add the A3M & A3F ends. Good information here Event Horizon & Services:Long Length MIDI Cables found via the Amazon link.

 

[hobbsies]

While $80 does seem excessive, I feel $31.80 (the actual price) is fair, considering the four connectors may cost $15-20 and factoring in labor. Plus I hate soldering DIN connectors, so I'd buy a short MIDI cable, chop that in half, and add the A3M & A3F ends. Good information here Event Horizon & Services:Long Length MIDI Cables found via the Amazon link.

Thanks for keeping this forum organized! That was a very useful link to read. I'm not sure why in the past the Express 48/96 hated the MIDI adapters but worked fine with a 100' midi cable (where the expression didn't seem to mind either cable), it is good to know there doesn't seem to be a big risk for MIDI not working over longer runs than 50'.

I actually just went out to see if I could buy a short midi cable and some XLR connectors, and found that they were going to cost me about $30 for the connectors and probably $10 for the cable. So I do agree, that the $32 pricetag on the adapters is reasonable. I'll see if I can't convince my PM to buy them again.

Thanks for all of the advice everyone!

 

[Amiers]

I would try to move to console before making up a way to move the MIDI. A 75' DMX cable would be easier to come by then trying to adapter rig the snake or an XLR cable to MIDI. Just my opinion.

 

[museav]

I believe that the MIDI standard calls for a maximum cable length of 15m or 50'. You certainly may be able to use longer runs in many cases but it might be greatly trial and error to see if it works.

The reason one device may work reliably and another not is pretty simple, not all devices are the same. One may be able to assume they meet all the related standards in terms of signal levels and signal quality but how well do they meet or exceed them? Do you have a source and desination that are both within prescribed limits in terms of the transmitted signals but in a manner that allows either greatly exceeding or barely making the 50' cable lenngth standard? There is often no way to know until you use the two devices together and try it.

Converting to XLR may let you run over an audio line such as in a snake but the connectors and inline connections themselves likely represent some signal degradation. The shielding, capacitance, etc. of the specific twisted pair audio cable used probably also affects just how long a run is possible. Again, you might have to try it and see, realizing that a situation working with one audio cable of any certain length may not mean it will work with all audio cables of that length.

 

[hobbsies]

I know this is an old post, but to follow up, I made 2 xlr -> MIDI adapters, popped them on a 100' XLR cable and it's working great. I cut a short Midi cable in half, I had to ignore 2 wires, and the 5th wire was the insulation, which was kind of annoying to solder, but it's all working just fine. Of course I forgot to slide on the bottom half of an XLR connector onto the midi cable before soldering the connector half on, but that was fixed with E-tape.