The short answer is yes. We have tested MIDI to 250ft and suspect in a normal RF noise environment it would run much further if quality cables are used with quality gear. Read on for more information
A while ago, we decided to question the 50 foot MIDI cable length maximum. It was spurred on by two things: first the need to make longer runs with MIDI; the second was a comment about why would you ever need to run it longer than 50 feet. (We say, why not?) We sell a great many 50ft cables and have never heard of a problem with them. So if we can safely do 50ft cables, why not go farther and see what happens?
We did testing on a couple of pieces of gear, figuring you could test all day and get similar but different results. We tested what we thought was a fair and reasonable length of 250ft using our top-grade MIDI cable, Mogami 2948, and a long length 100ft of Mogami 2-pair snake wire (W2930). With both attempts, the MIDI continued to work flawlessly.
Doing a signal analysis of the MIDI signal, it was clear that the longer you ran the signal, the more degraded the signal was, but with our gear, it was not bad enough to cause a problem. There were definite differences in the degradation between different pieces of equipment, most likely due to different input and output construction.
Where Theory Meets Reality
MIDI is a digital signal passing 1's and 0's from gear to gear in a data stream. The natural signal is a perfect square wave. Even through with one foot of cable you can see some degradation in the data. With digital, it all comes down to tolerance, so if you run a cable 100 feet will the input tolerate the resulting amount of degradation. Logic dictates gear is designed to handle some degradation; otherwise, the MIDI maximum length would be 0 feet. Tolerance is going to be equipment-specific; you might have one combination (equipment-out to equipment-in) that only tolerates 75 feet, whereas you might have another combination that tolerates 400 feet. The only way to know is to try it.
While we have had good luck with making these extreme runs, these were all performed in one environment at our offices. We have never had any major noise problems on any gear we have tested caused by our power or RF in the environment. The equipment tested with is relatively modern, and it seems to meet modern electrical standards.
Terms of Sale
We have decided to offer longer-than-specified MIDI cables. Though we believe you will most likely have no problems with them, we cannot guarantee them with all gear and in all environments. If you have very old gear or a high EMI/RFI noise environments, these lengths might not work or work well. These cables should not be depended on with unknown equipment or in new environments.
We offer these cables with our Limited Return policy listed on our "Shipping and Returns page," however we will make exceptions to cable lengths over 50 feet that did not work with your gear or environment. Restocking fees will depend on options purchased and condition of the cable upon return, to be handled on a case-by-case basis. For used cables past initial trials, we can cut the cables down to make standard length cables; fees will apply for labor and parts.
By purchasing these cables you agree to the terms listed here.
To see all our MIDI cables click here