MIDI over USB for real

[garcho]

I love MIDI. I'm not partial to the particularities of it, I just love the idea that there is a protocol that manufacturers actually stick to and is also really easy for DIY. That's awesome. The problem is...
...manufacturers stopped sticking to it when they switched over to mini-TRS. I just wasted too many minutes on figuring out what device expects what. Is it type A, B, rando, the only consistency is that it's super annoying.
How about USB-C? why not? It doesn't have to be USB protocol, just use the connectors and then we don't have to worry about anything. They're shielded, they have plenty of wires, they'll soon be truly ubiquitous. They'll also soon be one of the only cables left. Bluetooth has eaten most of the consumer connector business, including the "aux cable" industry. So a good time to switch is now, yeah?

[aron]

I haven't used the mini TRS. Are there multiple types of TRS implementations?

[FiveseveN]

Are there multiple types of TRS implementations?

Only two possible combinations so of course people used them both:

It doesn't have to be USB protocol

That sounds dangerous.
What's wrong with MIDI via Bluetooth/BLE, since you mentioned it?

In any case,

[ElectricDruid]

Is it worth asking what the MIDI standards body says about it? Do they provide any guidance on TRS wiring, or is it just a totally non-standard plug to use? In which case, yeah, all bets are off and different manufacturers will do different things.

MIDI-over-USB *has* been standardised, but it's a different thing since it uses actual USB protocol, not just borrowing some cables.

I realise that the original 5-pin DIN MIDI sockets are fairly large and a stereo 3.5 jack is ´much smaller, but (aside from the current vogue for "nano" pedals) most pedals could still find space for one.

[Ben N]

I realise that the original 5-pin DIN MIDI sockets are fairly large and a stereo 3.5 jack is ´much smaller, but (aside from the current vogue for "nano" pedals) most pedals could still find space for one.

Until fairly recently, most pedals that used MIDI have been fairly large footprint gizmos, with lots of parameters to futz about with or alter on the fly. That may be changing.

[ElectricDruid]

As FiveseveN pointed out, there's only really two ways to wire this up, so there's a chance that one way will become more common and win out over the other. It's not really in anyone's interest to have kit that's incompatible. That's the whole lesson of MIDI - make stuff that can easily work together, and everyone does better out of it: manufacturers, customers, everyone.

Even if just a few of the bigger players in the pedal world released a statement suggesting that they were all going to adopt one way over the other and inviting others to do the same, that would probably be enough. Once it has momentum, it's a done deal.

So...JHS, Catalinbread, etc etc..Over to you! We need you all to have a quick chat and pick one way over the other before this TRS thing turns into a train wreck!

[niektb]

Well, TRS Type A has been adapted by the MIDI 2.0 Standard so let's trash Type B once and for all 

[ElectricDruid]

Well, TRS Type A has been adapted by the MIDI 2.0 Standard so let's trash Type B once and for all 

Absolutely. That sounds pretty definitive to me. From now on, the other way is just wrong!

[garcho]

It's a bit of a Arturia vs Korg thing, A vs B, for the TRS. But if it was USB-C connectors and cables it wouldn't matter which one it is.
We should start using USB-C cables for all audio, not just digital data, but analog. Imagine a truly universal cable/connector/jack for analog, digital, power, etc. Wouldn't it be nice? (cue Beach Boys)

[ElectricDruid]

I don't agree. Isn't USB-C a 24-pin connector or something? That means there's at least a million ways for everyone to do it differently and get it wrong. Plus I don't think the cables are *actually* totally symmetrical - that trick is done with software at the ends. So if you tried feeding analog audio down it, you'd have to make sure you got it the right way around, which would be tricky with a cable which is visually identical at both ends. The plugs can even be put in upside-down, so the top row of contacts at one end is the bottom row at the other. Nightmare.

Honestly, TRS is a lot simpler!!

[Ben N]

Honestly, TRS is a lot simpler!!

I don't know much about MIDI, but the logic of using a 3-part connector for a 3 wire system seems pretty straightforward to me.

[Sweetalk]

MIDI TRS has been standardized, here's an image from the MIDI.org MIDI-to-TRS doc:


https://drive.google.com/file/d/1AEWRmHy-m_Qg4F9Y5MX0O0hyUkTQZmU1/view?usp=sharing

I don't agree. Isn't USB-C a 24-pin connector or something? That means there's at least a million ways for everyone to do it differently and get it wrong. Plus I don't think the cables are *actually* totally symmetrical - that trick is done with software at the ends. So if you tried feeding analog audio down it, you'd have to make sure you got it the right way around, which would be tricky with a cable which is visually identical at both ends. The plugs can even be put in upside-down, so the top row of contacts at one end is the bottom row at the other. Nightmare.

Honestly, TRS is a lot simpler!!

The USB-C connector is a 24 pin, but actually is a 12 pin connector with double pins, so when you plug the connector backwards the same connections are made. Obviously is standardized and has no pins assigned to audio or MIDI and this can be misleading to public if is used for something else. I can see people trying to connect a pedal to the computer via USB-C for MIDI and getting upset because it doesn't work  .

Honestly, the MIDI TRS is a really nice solution because it saves A LOT of space on a pedal enclosure, I had several commercial products developed that without the MIDI TRS would be impossible to add MIDI to them. Always followed that document's guidlines to be on the same road as the "standard" and inform on the user's manual that configuration.

[PRR]

24 pin, but actually is a 12 pin

Yeah.    https://i.postimg.cc/kM6BWdCR/usb-type-c-hdmi-f1.jpg

I remember when the small DIN was a "small" connector.

[mark2]

So if you tried feeding analog audio down it, you'd have to make sure you got it the right way around, which would be tricky with a cable which is visually identical at both ends.

Hah, what an absolute nightmare that'd be. Just when I thought guitar equipment was wonky enough....

That said, 6 conductors still is a lot to work with.

Taking it to the next generation, though... I wonder if any of the newfangled bluetooth research or tech will ever get to a point where it's feasible to have low enough latencies to start prototyping a seamless, wireless, mesh network of pedals. I'm partly sci-fi dreaming, partly joking, but also mostly serious. I'd love to just drop my pedals onto some mag connectors for power and use any arbitrary device to configure the board (your phone, one of the pedal's screens, etc)

As hilarious as the xkcd comic is, I've seen countless protocol RFCs in the software world stand the test of time for the most part. If they're well-designed, allow for sufficient wiggle room and expansion where possible, and introduced early enough before it becomes the wild west... people follow them.

I think we in the DIY world could easily pre-empt large scale commercial rollout of 20 competing wireless pedal systems.

[FiveseveN]

Already on it 

[Digital Larry]

I learned about TRS MIDI the hard way... bought a Headrush MX-5 demo from Sweetwater.  MIDI didn't work, but I hadn't tried it before the shortened warranty on demo kits expired.  So I replaced the main board and it still didn't work.  Then I took some MIDI F-F cable extenders and a couple pieces of solid wire to swap the 2 active lines and boom it worked.  Then I realized SW had tossed some random "1010 Music" DIN-TRS adapters into the box and they were the WRONG KIND! Ouch. 

[aron]

BeatBuddy used the PS/2 connector!

[ElectricDruid]

As hilarious as the xkcd comic is, I've seen countless protocol RFCs in the software world stand the test of time for the most part. If they're well-designed, allow for sufficient wiggle room and expansion where possible, and introduced early enough before it becomes the wild west... people follow them.

...and MIDI is a classic example. It's a format that's 40 years old and here we are still discussing it. There's other stuff which is even older - RS232 is still about (1960), and 4-20mA current loops (50s or 60s) have their place too. Even basic internet stuff like HTTP (1996) is getting pretty long in the tooth these days.

Hat tip to the late Dave Smith and Ikutaro Kakehashi for their efforts in getting everyone on board with it, and coming up with something that was good enough to last this long. The way the messages are designed to minimise processor overhead is really a piece of art.