Running midi long distances

[Manuel1975]

Hi There,

 

I'm looking for options to run midi signal long distances. About 100-200 meters. Have found some UTP and XLR options. Been working with both. Have had good results with utp and mixed results with midi over XLR using a midi line driver but cant say for shure that it was the line driver giving the problems. Really want to hear what your experiences are! Reliability and lag / delay is the main focus of attention.

 

It would be perfect to be able to work wireless but as I work live I don't truss wireless systems enough. Any experiences with this I would also love to hear about.

 

Hope you can share your experiences!

 

Manuel

[paulears]

That's too far - using XLR mic cables as extensions, I've got reliable operation up to 25m, but above that it's not good. Roland seems a bit more finicky than the Yamaha MIDI interfaces.I liked the Philip Rees line drivers for long lengths, but they've gone. I've heard good comments on the JL Cooper kit.

[sclg]

MIDI is a current loop interface so if you aren't using any sort of extender then basically the bigger the cable the better as it will have lower resistance. Core size will be more important than screening unless it's a very electrically noisy environment. I've never tried more than about 20m which was fine but I suspect your pushing your luck at 200!

If you are using extenders then one can only go on what the manufacturer recommends.

Steve

[mervaka]

Although the specification states 50ft (15m) max length, you should be able to go beyond this with a carefully considered transmission line, accounting for driver, cable and receiver. I'd take a look at something like http://www.midiextender.com for a cat5 based solution. I wouldn't trust XLR cable unless you were using a complete DMX based solution.

 

Over IP networks, you could take a look at RTP MIDI solutions.

[Manuel1975]

I own a jl cooper kit and am happy with the result but am looking for an second solution over an other type of cable to use backup. I had a show this weekend the location had trouble arranging a XLR line.. It took a lot of time to arrange and this made it impossible to test the connection and this was not good for the quality of the show. How ever, they had a spare utp cable. So now I want a backup solution just to make shure the next time it does not happen again... So I'm very interested in finding the best midi over utp solution:

 

Have you heard of:

 

http://www.kissbox.nl/products_new.html#midi

 

A little expensive...

 

And what about this option:

 

http://www.kentonuk.com/products/items/utilities/lndr.shtml

[paulears]

It's not a transmission line, is it? Just a current loop? Hence the need for decent sized conductors, unlike those found in most pre-made MIDI cables.

[Manuel1975]

Sorry,

 

I dont know what a "transmission line" is? Or a "current loop"?

 

Please explain...

[sclg]

Sorry,

 

I dont know what a "transmission line" is? Or a "current loop"?

 

Please explain...

Modern network cables and suchlike depend on the receiver sensing a voltage change at the end of the cable. As such they are often referred to (reasonably accurately) as a transmission line because they are very subject to all sorts of interference and can operate at high frequencies which involve all sorts of annoying effects.

Midi is a very old technology. It uses a 'current loop' which means the far end senses the current flowing through the cable rather than the voltage across it. It is also a relatively low frequency so transmission line effects - which things like twisted pair cable try to reduce - are far less relevant.

 

Obviously, (Ohms law) current and voltage are related anyway but other posters are right that for midi, because CURRENT is what matters, you need a low RESISTANCE cable. Mic cable is not ideal! (At least, not for significant lengths.)

 

As I mentioned earlier, if you are using midi extenders, they may not actually be using midi-type signals at all between the extender transmitter and receiver so you need to see what the manufacturer says.

 

Steve

[Manuel1975]

The solutions I've used so far all involved a converter box on both side of the cable which convert midi to an other type of signal so it can be sent over XLR or utp over greater distances.

 

Has any body worked with wireless midi? This sounds to good to be true:

 

http://www.kentonuk.com/products/items/wireless/midistream.shtml

[dbuckley]

Have you heard of:

 

http://www.kissbox.nl/products_new.html#midi Kissbox

 

Kissbox well regarded; it isn't really a MIDI "extender", it is a MIDI to TCP/IP converter, and so what you have between your kissboxen is an Ethernet network.

 

Generally, one uses a kissbox at the "far", device end of the link, and have a software interface on the computer at the near end of the link, assuming there is a computer involved.

[Manuel1975]

Have posted the same question on gearsluts and someone came up with this little baby:

 

http://www.ctpsystems.co.uk/midi.html

 

It looks super SEXI. No external adapter and only on of the two units needs power... Very tour-able...

 

Does anybody have experiences with this?

[mervaka]

It's not a transmission line, is it? Just a current loop? Hence the need for decent sized conductors, unlike those found in most pre-made MIDI cables.

Anything carrying a signal across a long distance should be treated as a transmission line. You need to consider the capacitive and inductive effects that are acted upon the signal.

[Brian]

Anything carrying a signal across a long distance should be treated as a transmission line.

Although you need to know what 'long' means. A quick BOFP calculation would seem to indicate that MIDI cables become 'long' at around 800m.

[BlueShift]

Have posted the same question on gearsluts and someone came up with this little baby:

 

http://www.ctpsystems.co.uk/midi.html

 

It looks super SEXI. No external adapter and only on of the two units needs power... Very tour-able...

 

Does anybody have experiences with this?

 

That was me ;)

 

They are great. In fact pretty much everything Chris Thorpe makes is excellent. His main market is broadcast, and I have yet to come across an OB without something of his racked up somewhere...

[Manuel1975]

Have posted the same question on gearsluts and someone came up with this little baby:

 

http://www.ctpsystems.co.uk/midi.html

 

It looks super SEXI. No external adapter and only on of the two units needs power... Very tour-able...

 

Does anybody have experiences with this?

 

That was me ;)

 

They are great. In fact pretty much everything Chris Thorpe makes is excellent. His main market is broadcast, and I have yet to come across an OB without something of his racked up somewhere...

 

Now where is this like button when you need it?

 

:D