The Newly Standardised Future of 3.5mm MIDI Connections

You may have noticed the recent trend of manufacturers using 3.5mm connectors on devices in place of the classic 5-pin DIN MIDI socket. This is of course because these devices are physically too small to feature the sizable 13.2 mm diameter ring of a standard MIDI plug. Brands have actually been implementing this practice for a while now — the earliest example being the Line 6 MIDI Mobilizer back in 2010. This is all well and good, but predictably, when manufacturers break standards, complications arise.

First is the dreaded inclusion of dongles. The 3.5mm to 5-pin DIN adaptor supplied with these types of devices is another little thing to potentially lose. Secondly, not all adaptors are designed the same way. As this “How to Make Your Own 3.5mm mini stereo TRS-to-MIDI 5 pin DIN cables” article explains, the adaptor wiring used on the aforementioned Line 6 MIDI Mobilizer and various Korg products (e.g. Electribe 2 and SQ-1) can be referred to as ‘TRS MIDI A’, whereas Arturia (e.g. Beatstep Pro and Keystep) and Novation (e.g. Circuit and Launchpad Pro) use the alternate ‘TRS MIDI B’ wiring.

This inconveniently whimsical polarity preference (editors note: this is possibly the best sentence I’ve ever read) means adapters are not necessarily interchangeable between brands. If you lose your Korg Electribe 2 MIDI adapters for example, you cannot simply use the ones from your Arturia Beatstep Pro. To further complicate things, the Beatstep Pro ships with a similar looking 3.5mm to 5-pin DIN adaptor that’s wired differently again, this time for clock syncing purposes.

To make matters even worse, the newly announced Novation Launchkey Mini MK3 has a ‘TRS MIDI B’ wiring 3.5mm MIDI socket, but does not include any 5-pin DIN adaptors at all!

Where this all feels a little nonsensical when you consider controlling a Korg Electribe 2 using with a Novation Launchkey Mini MK3. You will need to adapt the Electribe 3.5mm MIDI in port to a 5-pin DIN plug using their Type A adaptor, connect a MIDI cable, then adapt it back to 3.5mm MIDI out port at the Launchkey end using their Type B adaptor, which you’ll need to source yourself. This is somewhat ironic as the MIDI standard was first devised as a method for allowing instruments from a variety of brands to speak to each other easily via a single cable.

Fortunately, team MIDI (The MIDI Manufacturers Association) have stepped up to the plate and published an official standard for 3.5mm TRS MIDI adaptors which you can read here. 

What this means for the end user is (after brand adoption) not only that adaptors will be compatible between brands, but that they may no longer be required at all. With this standard in place one could simply connect two compatible devices together using regular 3.5mm TRS cables, no 5-Pin DIN plugs required.

This has been theoretically possible the whole time, provided both devices share the same 3.5mm TRS wiring. For other cases, the internet has come up with an ingenious MIDI life hack:

The first device we’ve seen to officially conform to the standard is the recently announced Korg NuTekt NTS-1 DIY synth which puts Korg’s versatile Multi-Engine oscillator and effects from the prologue into tiny, affordable package.

Although I may eventually miss the pleasing sensation of successfully socketed 5-Pin DIN connector, I do love the idea of exclusively using these ubiquitous and readily available 3.5mm cables between devices, even if the smartphone and laptop industry are steadily abandoning them completely.