Meris Midi Cable build request (if doable!!)

[Kev]

So for those familiar with Meris pedals, they're one of those pesky builders who think it's a great idea to not put midi din sockets on their pedals.  Meris use a single TRS Midi application to send and receive Midi.  They also sell a ridiculously expensive I/O box that you plug your TRS into and get yourself a Midi Din in and out.

 

I don't want to spend £100 to let me use my Quad Cortex as a midi controller, so what I am looking for is a cable to do the job.

 

Is it possible to take a TRS plug and split it into two DIN plugs, one dealing with sending Midi from TRS (tip maybe, not sure!) and one receiving (ring??).  Ie basically doing exactly what the Midi I/O box is doing, without having to find space for a big metal box under my board?

 

If it is, who can build it for me?? 😁

[bloke_zero]

Sounds weird. All the midi trs I have require a connector for both in and out as there needs to be a connection for the optocoupler (yeah - I only vaguely know what I'm talking about!). Out of interest I googled
 

"Transmit MIDI on the ring and receive MIDI on the tip of the TRS cable" and got:

 

https://www.midi.org/midi/forum/8439-receiving-midi-on-trs-ring

 

Which I *think* answers your question - you need the box otherwise it might well not work as the external MIDI device needs the additional connection - which in this case is provided by the box.

[BigRedX]

@bloke_zero has beaten me to it.

 

Some additional information. Traditional MIDI uses three conductors in the cables with 5-pin DIN sockets on them. Two for the data and one for the screen/earth. On the MIDI In socket, all of these connections should be isolated from the receiving device. The screen is simply terminates at the socket and should not be connected to the earth of the receiving device. Similarly the two conductors transmitting the data are onto-isolated from the rest of the circuitry. MIDI was design this way from the ground up to stop it from forming earth loops with the audio side of your gear. Therefore if you are getting earth hum it shouldn't be caused by your MIDI connections.

 

The very original MIDI spec suggested XLR connectors but this was over-ruled by the Japanese manufacturers who want to keep costs down by using 5-pin DIN instead. These days the situation is even worse with all sorts of plugs and sockets masquerading as MIDI connections. Some are actual MIDI connections and some like the socket on your Meris Pedal need additional devices to make them function in the same way. Also the original MIDI spec said that if your device sports MIDI connectors other than the traditional 5-pin DIN it should be supplied with a suitable adaptor. My Tenori-On which has a multi-way mini DIN socket came with a lead that terminated in MIDI In and Out in-line sockets.

 

Unfortunately you are almost definitely going to need the expensive adaptor box if your want MIDI control of your Meris pedal. If it was possible to use a single TRS jack to supply both MIDI In and Out, there would be no isolation of either the screen or the data connection which would almost certainly lead to earth loops and hum.

Edited July 17, 2023 by BigRedX

[Brucegill]

You can 100% get a midi Din to 1/4” trs cable made up for Meris specs (pretty sure Meris use TRS type-A). You could probably get away with a Din to 1/8” TRS with a stereo headphone 1/8” to 1/4” converter on the end. Obviously this will only do Midi one way - but do you really need Midi In and Out to the Meris? 
 

https://www.disasterareadesigns.com/shop/p/5p-trs-pro-midi-cable

 

sure Designacables could make one up for you 

 

edit:

https://www.designacable.com/midi-over-1-4-jack-cable-angled-trs-to-din-lead-typea-typeb.html

Edited July 17, 2023 by Brucegill

[BigRedX]

Having looked at the manual for the Meris MIDI I/O it looks as though you can do what you want with a 5-pin DIN to TRS jack.

 

However this is only possible because Meris have chosen to ignore the MIDI conventions designed to protect your MIDI equipment and prevent ground loops and hum on the audio side. Using a single three conductor cable for both MIDI in and MIDI out means that you dispense with both screening isolation, and opt-isloation of the data signal. IMO you use at your own risk.

[bloke_zero]

48 minutes ago, BigRedX said:

Using a single three conductor cable for both MIDI in and MIDI out means that you dispense with both screening isolation, and opt-isloation of the data signal.

To be fair - they don't suggest doing this - they suggest buying their box that has the isolation stuff in it.  Which seems weird to me. 2 x 3.5mm trs (for in and out - this is a MIDI 'standard') or mini USB with MIDI seems like a more user friendly solution.

[Kev]

2 hours ago, Brucegill said:

 Obviously this will only do Midi one way - but do you really need Midi In and Out to the Meris? 

Obviously sending midi to it is by far the most important thing, but the Meris is made a LOT easier to program by using a desktop editor, and the editor needs to receive midi from the Meris to load and save the presets.

 

I contacted designacable who seemed to think it isn't possible to split a TRS into a midi in/out, so its looking like it isn't going to be possible.  Sending Midi from QC to TRS shouldn't be a problem and those cables are readily available (although I'm struggling to find cables that specify what midi type they're for as it differs?).

 

I just don't want to buy that box, but from looking online the other ones available that are cheaper just don't work both ways.

 

EDIT: This is the editor I'd want to use: https://studiocode.dev/ottobit-editor/

Edited July 17, 2023 by Kev

[Kev]

1 hour ago, BigRedX said:

Having looked at the manual for the Meris MIDI I/O it looks as though you can do what you want with a 5-pin DIN to TRS jack.

 

However this is only possible because Meris have chosen to ignore the MIDI conventions designed to protect your MIDI equipment and prevent ground loops and hum on the audio side. Using a single three conductor cable for both MIDI in and MIDI out means that you dispense with both screening isolation, and opt-isloation of the data signal. IMO you use at your own risk.

I'm incredibly green when it comes to Midi so I really don't know much about that at all.  I assume their splitter box provides the isolation needed?  I just don't understand why companies like Meris and Source Audio don't just allow space for the DIN sockets.  The cynical side of me does, but its just daft, especially when this pedal needs midi so much to be useable.  There is no way to access any of the 15 other presets without midi use, or the use of their (proprietary, shockingly) external footswitch.

[BigRedX]

All the connections appear to be there for both MIDI In and Out, however because they share a common ground, in making up a TRS Jack to 2 x 5-pin DIN connectors you'll be potentially creating an earth loop between the MIDI In and Out at the other end of the cable.

 

In a way I can see why Meris have done this. It allows them to use one of the existing sockets on their pedals as a MIDI connection using a reasonably gig-proof connector (1/4" jack). From an electrical PoV separate 3.5mm mini-jacks for MIDI in and out would be better, but they're not as robust unless the pedal and everything it connects to for MIDI live permanently on a pedal board.

 

MIDI over USB isn't really MIDI, it's just a communication protocol that allows MIDI-type data to for end between devices. However unlike traditional MIDI which is a peer-to-peer protocol, MIDI over USB requires one of the devices (usually the computer) to be the "host" which controls the transmission of data to everything else. Also IMO USB connectors (especially the smaller ones like USB C) have no business being on equipment that is intended for serious gigging use. They and the cables they come with simply aren't robust enough. (Even though I use a USB C connection for the foot pedal used to control our backing - I carry a spare - and the pedal itself is not mission-critical, just convenient).

[Kev]

It sounds messy, so I've just gone with a Din to TRS and will just send midi to the pedal.  I realised that you can still use one of the editors if you make presets using it and save those presets into a library on the PC, and recreate any new presets you make on the pedal and save in library etc and load them on as needed.  Fiddly but workable.

 

Never used the QC to send midi, so lets hope that's simple and it works...

[Kev]

...it didn't.

 

Setting the Meris up to received Midi over TRS on a specific channel and connecting the cable to the Quad Cortex, setting the QC to send PC messages across the same channel, there is no sign the Meris is receiving anything.  The QC can send and receive messages over USB midi with my PC with no issue but nothing I try gets it to communicate with the Meris.  I'm assuming the cable is wrong, as otherwise it means there is something wrong with the Meris I guess?  I've emailed Designacable to ask them how they've wired it, but you'd assume if they say they're familiar with Meris and realise its a different wiring they wouldn't get it wrong.

 

Sigh.

[Brucegill]

sometimes you can pull the trs cable half out of the socket and it’ll make the tip of the cable hit the sleeve of the pedal input - so essentially swapping the type of cable. 
 

also need to check you’ve done all the hidden settings on the Meris to receive midi etc. 

[Kev]

1 hour ago, Brucegill said:

sometimes you can pull the trs cable half out of the socket and it’ll make the tip of the cable hit the sleeve of the pedal input - so essentially swapping the type of cable. 
 

also need to check you’ve done all the hidden settings on the Meris to receive midi etc. 

Yeah all global config settings are set right.

 

I'm waiting for designacable to come back as they've literally sold the cable to me as a Meris Midi Cable, so I'll see what they say.  But I've fiddled with the jack when sending midi to no effect.

[Brucegill]

Just had a thought…

 

Have you got one of these lying around?

https://www.gear4music.com/Books-DVD-and-Sheet-Music/Hosa-YPP-117-Stereo-Breakout-Cable-1-4-TRS-to-Dual-1-4-TSF/L1N?gclid=CjwKCAjwtuOlBhBREiwA7agf1pGaMfM9_My_ymbRJMpM6rM79glrhSgzjrZFOuuA76YASvn3Xc6t6hoCPSsQAvD_BwE&utm_source=tradedoubler&utm_medium=affiliate&utm_content=0&tduid=039b5eef7c27b2f1d41788f64b903641&network=tradedoubler&affiliate_id=3291325&publisher=Adstrong+CSS+UK
 

Put the DIN>TRS into the splitter left channel > Meris. Then try the mono into the right channel > Meris. 
 

you’d essentially end up sending the midi out to the tip or the ring so both type A and type B. 
 

does that make sense? I’ve used this before to trouble shoot 

Edited July 20, 2023 by Brucegill

[Brucegill]

I’ve got one here I can post out to try if you want. 
 

another thing to try is send a program change from the laptop if you have a USB > midi converter (also have one here you can try). Then you could eliminate the QC out of the equation. 
 

and I have a chase bliss midi box that I think has jumpers internally to convert the outputs to Meris. But I’d need to open it up and check. 
 

god, I hate midi lol. Always makes life too complicated. 
 

drop me a PM 😀

Edited July 20, 2023 by Brucegill

[tauzero]

Just trying to work out how Meris would be doing this. I assume that there's a common ground, one of tip/ring in, and the other out. Would optoisolation work both ways, or would the receiving device be assumed to be handling its own optoisolation? The black box would contain an optoisolator which would be powered from the IN DIN socket (connected to the OUT DIN socket of the Quad Cortex). That would take the input signal and isolate it, then pass it on to the Meris which presumably doesn't have optoisolation. There might be another optoisolator to go the other way. I may be wrong, of course, but it does seem like not a lot to pay £100 for - one stereo jack socket, two DIN sockets, and an optoisolator or two.

[BigRedX]

6 hours ago, tauzero said:

Just trying to work out how Meris would be doing this. I assume that there's a common ground, one of tip/ring in, and the other out. Would optoisolation work both ways, or would the receiving device be assumed to be handling its own optoisolation? The black box would contain an optoisolator which would be powered from the IN DIN socket (connected to the OUT DIN socket of the Quad Cortex). That would take the input signal and isolate it, then pass it on to the Meris which presumably doesn't have optoisolation. There might be another optoisolator to go the other way. I may be wrong, of course, but it does seem like not a lot to pay £100 for - one stereo jack socket, two DIN sockets, and an optoisolator or two.

 

It's probably possible to have two opto-isolators running in opposite directions, but you still need to completely decouple the screen from the earth, and ultimately it would almost definitely be cheaper just to fit standard MIDI sockets and a single opto-isolator like most other manufacturers do.

 

I suppose Meris assume that a lot of their users will never need to MIDI facilities, so there is little need to fit conventional sockets and circuitry, and those that do will be willing to pay for the additional interface box.

 

To the OP can you check that the correct (or even any) MIDI data is being transmitted from the QC MIDI out? I have found that some devices are very poor at re-transmitting MIDI over USB to the actual DIN MIDI sockets with either no MIDI or very garbled messages being output.

[Brucegill]

 

this is the guts of an older Chase Bliss midi box if it helps work out what’s going on in these things. (It has jumpers to use with Empress or CB.)

 

 

[Kev]

9 hours ago, Brucegill said:

I’ve got one here I can post out to try if you want. 
 

another thing to try is send a program change from the laptop if you have a USB > midi converter (also have one here you can try). Then you could eliminate the QC out of the equation. 
 

and I have a chase bliss midi box that I think has jumpers internally to convert the outputs to Meris. But I’d need to open it up and check. 
 

god, I hate midi lol. Always makes life too complicated. 
 

drop me a PM 😀

 

Thanks for the suggestions!  Rob has asked that I send the cable back so he can have a look and do some digging.

 

I don't have another midi usb adapater to use, but given the QC is responding to midi commands the issue I assume is going to lie with the QC not outputting midi through its midi out, or (more likely) there is an issue with the cable.

 

 

3 minutes ago, BigRedX said:

 

It's probably possible to have two opto-isolators running in opposite directions, but you still need to completely decouple the screen from the earth, and ultimately it would almost definitely be cheaper just to fit standard MIDI sockets and a single opto-isolator like most other manufacturers do.

 

I suppose Meris assume that a lot of their users will never need to MIDI facilities, so there is little need to fit conventional sockets and circuitry, and those that do will be willing to pay for the additional interface box.

 

To the OP can you check that the correct (or even any) MIDI data is being transmitted from the QC MIDI out? I have found that some devices are very poor at re-transmitting MIDI over USB to the actual DIN MIDI sockets with either no MIDI or very garbled messages being output.

 

To be honest, the pedal is almost unusable without Midi in some ways.  The sequencer is very fiddly to set up just using the knobs on the pedal, and there is literally no way to use any of the preset functionality without midi.  Its just so frustrating they didn't design it with the standard Din sockets.

 

I don't have anything that can check that unfortunately.  I know the QC is sending Midi messages internally (the QC is set to channel 1, and sending Midi messages to channel 1 causes to the QC to receive and act upon messages) but I don't have any other midi devices at the moment.

[BigRedX]

I suspect that one of the things making the interface box expensive, is that not only is it an interface box, but it also has to act as a MIDI Thru and MIDI Merge. When you start looking at the prices for these devices £100 doesn't seem quite so bad.

[Kev]

1 hour ago, Brucegill said:

 

this is the guts of an older Chase Bliss midi box if it helps work out what’s going on in these things. (It has jumpers to use with Empress or CB.)

 

 

One of those would appear to do the trick and are somewhat cheaper than the midi i/o, if less available...

[Brucegill]

4 minutes ago, Kev said:

One of those would appear to do the trick and are somewhat cheaper than the midi i/o, if less available...

 

its only midi in and midi thru FYI

[Kev]

24 minutes ago, Brucegill said:

 

its only midi in and midi thru FYI

At this stage I'd happily forget about receiving midi from the Meris and just let it receive midi from the Quad Cortex...

[Kev]

The headache continues.

 

So, I decided to just buy the Midi I/O, which I have done.  QC can now send messages to the Ottobit, great stuff.  However, when connecting the QC over USB and trying to use the desktop editor (changing the QC midi setting to thru), the Meris is not receiving nor sending any Midi.

 

On 21/07/2023 at 09:53, BigRedX said:

 

 i have found that some devices are very poor at re-transmitting MIDI over USB to the actual DIN MIDI sockets with either no MIDI or very garbled messages being output.

 

Id hope that a £1600 processor doesn't fall into this category, but could this be a factor?  I have emailed Neural DSP for help.

 

At the point of considering moving this pedal on as this is a whole lot of fuss for something that seems like it should be simple!  I'm NOT prepared to invest any further, but if I did I guess the next thing would be to buy a USB midi interface to cut the QC out the chain.

 

EDIT: Neural have confirmed it's the QC, it can't send messages from midi usb through DIN.

 

Sigh.  I'm not buying a USB Midi cable, have to draw a line somewhere!  So, fiddly interface it is! 

 

Nothing is easy, eh?

Edited July 26, 2023 by Kev

[BigRedX]

14 hours ago, Kev said:

Sigh.  I'm not buying a USB Midi cable, have to draw a line somewhere!  So, fiddly interface it is! 

 

Don't buy a USB to MIDI cable. Nearly all of them are terrible for the sorts of things that you want to do (I post from experience). You will need a proper MIDI interface and one that does not automatically filter out the more esoteric MIDI messages such as MTC and SysEx.