Trying to solve Organelle > Midihub bus power zipper and ticking noise issue

Midihub Support
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Hiya folks!

I’m trying to troubleshoot something, so I figured to see if you all have any ideas (@thetechnobear it seems like you are an expert with both Organelle and Midihub, so maybe you and @Giedrius and others may have some pointers).

I’m experiencing weird noise issues when bus-powering Midihub from my C&G Organelle. I notice audible ticking sounds when playing keyboard controllers through Midihub (both note on and note off messages make a little noise) … the controllers usually being 2X QuNexuses (mostly) controlling a C&G Organelle and Pocket Piano, Chase Bliss Mood, sometimes IOS synths, other doodads, etc.

More distractingly audible – when I trigger continuous streams of midi messages (turning an encoder, ramping an expression pedal hooked up to a Morningstar MC8 on the floor, or coming from iOS midi controller apps, etc) I get a kind of zipper sound, like a bunch of those little tick sounds happening every time a midi message goes through Midihub, which naturally gets exaggerated when ramping up and down a CC value spectrum.

This doesn’t happen when when Midihub is powered via another usb power source (battery power bank, usb charger, usb power I’ve rigged up with a tiny buck converter gizmo on the board, etc). So, as far as I can tell (from ruling out a bunch of other things too), the noise is only really audible when the Organelle is hooked up to (and powering) Midihub via USB.

The organelle gets roughly 1000 mA center positive, coming from two 500 mA Strymon Zuma outputs combined with a current doubling (not voltage doubling) and polarity inverting cord. I’ve also tried plugging the Organelle in with it’s own dedicated wall wart of the appropriate specs, and same usb connection between the Organelle and Midihub, to rule out the Zuma power as the issue (see if Organelle just needed more current to manage the bus-powering of Midihub). But that set up still results in the same amount of noise.

Anyhow, sorry for the long post … I just figured the more information the better for troubleshooting. The only relatively simple – albeit not cheap – solution I can think of is to get a CME Uhost to power the Midihub, and stick a Widi Bud thing in the Organelle to pass back and forth bluetooth midi between Organelle <> Midihub (I don’t have enough DIN ports left on Midihub to do a wired connection to the Organelle).

But do you all have any other troubleshooting ideas? I can also reach out to the Critter & Guitari folks, but figured this forum might have deeper-level knowledge of the power needs and intricacies of Midihub.

Thanks for making it through the ramble, if you did!
-Joe

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What sound sources are affected? Is it Organelle itself generating the audio?

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Hi @Giedrius … thanks for responding!

Good question … I here the noise even when everything is muted, no instruments are generating sounds or are connected, and pedals are physically bypassed (via the Switchblade 8F matrix switcher, true bypasses, etc). I’ve plugged and unplugged as many different things as I can manage to see if I can isolate something actually generating the noise. it seems more dependent on power connections than audio connections, even though everything gets pretty well isolated power from the Strymon supplies. But I’m sure some of it has to do with the sheer number of things powered and connected, and maybe some grounding issue somewhere in there

I tested with the volume jacked up to see which kind of midi messages are triggering the noise, and it seems all of them are, to varying degrees. Taking things in and out of the mix (especially power to pedals) seems to make the noise louder or softer, but it’s always there unless I power the Midihub with a spare battery power bank thing, or from another USB port I have rigged for the QuNexuses. I’ll experiment with some more things to see if anything makes a big difference!

Thanks again for the help … I’ll let you know if I can suss anymore out.

-Joe

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Hi @Giedrius,

I tried a bunch more things, and found a couple things that impact the noise distinctly!

One being that the issue with the noise happens if Midihub is bus powered from my Organelle and also when it’s bus powered from my computer (but the noise doesn’t happen if Midihub is powered by a power bank or other usb source).

And a big thing I figured out is that the noise only seems to happen when I have the Chase Bliss Mood MKII connected to Midihub … when I disconnect Mood from Midihub the noise stops happening. It uses a 5 pin midi to special (ring active I think) TRS cable to connect with Mood (or any other Chase Bliss pedal). I tried another cable (the same type) and the noise still happened. I also tried connecting the cable from Midihub to another Chase Bliss pedal instead (Blooper), to see if the Mood pedal was the issue. But connecting to the other Chase Bliss blooper pedal also resulted in the same sounds happening.

Interestingly, the noise happened whether or not Mood is connected to power, or inserted or removed from the signal chain. Though if Mood is in the signal chain and I disconnect Mood’s 1/4 inch audio output, the noises don’t happen (and of course audio isn’t passed through).

So it seems something to do with the connection between Midihub and Chase Bliss pedals (or the type of cable used). The 5 pin to ring active TRS cable I usually use is this one from Disaster Area Designs:

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

Disaster Area’s page mentions that pin 2 of the midi controller’s output needs to be earthed / grounded for the CBA adapter cable to work properly. Could this have anything to do with it?

Granted, it is still only an issue when bus powered via the Organelle or my computer, so in the end maybe I’ll just have to try one of CME’s UHosts to power Midihub while still getting midi to and from the organelle. I could send some other things in and out of Midihub’s USB port too, in that case, which would be handy.

But if you have any other ideas of troubleshooting this without going with the bluetooth connectors, let me know!

Thanks again,
-Joe

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Midihub’s outputs have the pin 2 grounded.

I suspect it might be something special in Chase Bliss MIDI input implementation - according to the MIDI standard, there must be an optocoupler used, meant to avoid any possible noise and ground loop issues, like what you’re witnessing.

The MIDI input jack on Chase Bliss Mood has some extra functionality, as mentioned in its manual:

The MIDI jack can also be used to engage MOOD’s Wet Channel with an external footswitch. Useful for tabletop setups. Plug any normally-open momentary footswitch in and you’re all set, it takes control automatically.

This might indicate that it’s using some custom implementation. The manual and the MIDI manual seem to strongly suggest using Chase Bliss MIDIbox for converting from DIN-5 to a suitable MIDI connection for their pedals.

Maybe using the MIDIbox would solve the noise issue, but I’m just guessing. :slight_smile:

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Yeah that’s a reasonable idea! Though with all my other chase bliss pedals, I convert midi to their specifications using either a disaster area designs Midibox or simply the same kind of midi plug to trs ring positive plug I’m using with Midihub, and they’ve never caused the same issue. That could well have to do with those other converter devices not being powered through bus power from computers / microcomputers (Organelle).

I can holler at the Chase Bliss folks and see what they think would work best. Though after considering using CME’s UHost widi bluetooth midi gizmo, that might be simpler anyways, and it would give me a good way to get midi to and from an iPhone/ipad too.

I suppose a separate question on the would be: Have you all experimented with using a CME UHost with Midihub? (powering it and sending bluetooth midi back and forth from other things). Being able to use the one port for both the Organelle and an iPhone or iPad would be useful, as long as I’m careful with programming the things to filter channels and avoid midi loops. Though I’m not sure exactly how well the UHost’s merging and thru functions work. I’m sure I could pair just the midihub and organelle, but getting an extra connection with bluetooth devices would solve a lot of other stuff too

1 Like
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I haven’t tried the CME devices, but there was a thread here some time ago on WIDI master, maybe there’s some useful info: MidiHub and WiDi Master

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in case it’s of interest, @Joe_Novelli, @deebee posted a comprehensive solution about setting up a more complex WIDI setup with Midihub (starting about here for context)

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Thanks @resonotter and @Giedrius ! I’ll look more into the widi stuff, especially for simplifying the ipad/iphone connection.

And @Giedrius i talked with Daniel at Chase Bliss and you’re right about the likely reason for the noise … they always recommend the midibox in between because both the chase bliss and disaster area midiboxes’ outputs are opto-isolated, mitigating challenges with the chase bliss midi trs jack implementation

So I’m trying to figure out if there’s a way to stick an in-line opto-isolater between Midihub and the Mood. I could get another of their midiboxes to put in between, but I’ve run out of room and power under the board, so another solution would be ideal … either via widi or some type of opto-isolating adapter that could run off midihub’s midi output power. I saw this little gizmo I could solder together and try if it seems it might work:

ubld.it™ - MIDI Breakout Board MV (Multi Voltage) https://a.co/d/3FefyPv

1 Like
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Usually the opto-isolation is on the input side of the receiving device, powered by the receiving device itself. I think it’d be best to consult with Chase Bliss for the minimal electronic solution you could employ to avoid the noise issues, they might be able to share some insight on how their MIDIbox solves it for their devices. :slight_smile: