Roger Linn Design

rlauriston · Post by **rlauriston** » Tue Dec 04, 2018 11:19 pm

I've got the iPad Pro and the LinnStrument both connected to a powered hub. The LinnStrument does not show up as a MIDI device in Animoog or GeoShred.

Roger_Linn · Post by **Roger_Linn** » Tue Dec 04, 2018 11:28 pm

As with all MIDI problems, you’ll need to trace down the cause. Start by removing the powered hub and see if it works with only LinnStrument through the Apple USB adaptor. Or try connecting a different MIDI USB keyboard to your hub and see if the same problem exists. Or connect directly through Apple’s adaptor and see if that works. Or read the LinnStrument FAQ page, Problems tab, specifically the FAQ “My LinnStrument is not sending MIDI. What’s wrong?”.

rlauriston · Post by **rlauriston** » Tue Dec 04, 2018 11:37 pm

The LinnStrument was sending MIDI fine a week or so ago when I was trying to get it to work with my old iPad.

The USB-C to Type B cable and adapters I ordered haven't shown up yet.

The iPad Pro doesn't see my keyboard or drum pad either, so I suspect there's some basic issue.

Roger_Linn · Post by **Roger_Linn** » Tue Dec 04, 2018 11:59 pm

I think you're saying that the LinnStrument worked fine with your old iPad but doesn't doesn't yet work with your new iPad and your new MIDI hub (whatever that is). That tells me that you haven't configured your MIDI hub correctly.

rlauriston · Post by **rlauriston** » Wed Dec 05, 2018 12:23 am

It's just a powered USB hub. Nothing to configure. The LinnStrument works fine with my Mac over the same hub.

Apple support told me to reach out the manufacturers, but with class-compliant MIDI devices, I don't think anyone's going to have a clue until they get their hands on a new iPad Pro.

Roger_Linn · Post by **Roger_Linn** » Wed Dec 05, 2018 12:26 am

Once again: if LinnStrument works over USB with any other devices, then LinnStrument is working correctly. How could it be otherwise? If you connect a guitar into one amplifier and it works but doesn't work with another amplifier, would you think the guitar is the problem? No, you'd know that the second amplifier is the problem.

I have a new iPad Pro and it works perfectly with Apple's USB-C to USB-B adaptor.

Did you read my suggested FAQ on the FAQ page?

rlauriston · Post by **rlauriston** » Wed Dec 05, 2018 12:40 am

Problem solved. I connected a third-party USB-C port expander to the iPad Pro and connected the LinnStrument to one of its USB Type A ports and it works perfectly. I can hook a USB AC adapter to the port expander.

I wonder what the difference is between that and a USB hub?

Tj Shredder · Post by **Tj Shredder** » Wed Dec 05, 2018 1:50 pm

Direction? USB-c cables have the same plug on both ends. It does not translate anything. The adapters translate...

rlauriston · Post by **rlauriston** » Wed Dec 05, 2018 8:37 pm

The iPad Pro can see the Linnstrument and other MIDI class-compliant devices when they're connected via the port expander but not when connected via the powered USB hub (which works fine to connect my array of MIDI devices to my MacBook). I can work with that but I'd like to know what the issue is.

I'm using the same USB-C to Type A cable to connect the iPad Pro to the powered USB hub and the port expander, so there's no problem with the cable.

This is the port expander.

https://www.amazon.com/gp/product/B073VXZCTN

rlauriston · Post by **rlauriston** » Wed Dec 05, 2018 8:56 pm

Oh, wait, I'm not using the same cable. The port expander has its own USB-C cable. So the cable could be the problem.

Maybe I'll take the USB hub, iPad, and MPD18 down to the Apple Store and see if they have a cable that will work.

At least the LinnStrument and iPad are getting along fine.

rlauriston · Post by **rlauriston** » Wed Dec 05, 2018 9:15 pm

Geert Bevin came up with the answer: I need to connect the iPad to the USB hub's host port. D'oh!

rlauriston · Post by **rlauriston** » Fri Dec 07, 2018 8:58 pm

Direct connection with a third-party USB-C to USB Type B cable also works.

https://www.amazon.com/gp/product/B07DCNPQL4

SteveElbows · Post by **SteveElbows** » Sun Dec 09, 2018 5:07 pm

I'm really quite impressed with how much power is available from the new iPad pros usb c port. The old iOS usb 'this device needs too much power' messages are a thing of the past without having to use any of the old power workarounds.

I've just done a test where I use a cheap Lenovo non-powered usb c->4x usb 3 mini hub. I was able to power four bus powered devices simultaneously from the iPad Pro using it. The devices were the full sized linnstrument (not in low powered mode), a seaboard block, the expressive e touche, and a zoom u-24 audio interface.

rlauriston · Post by **rlauriston** » Sun Dec 09, 2018 5:32 pm

How long can it power that rig on one charge?

I tried one powered hub (Monoprice USB Super Speed Hub 7) and it turned out not to supply power to the host port and not to work at all with the iPad, though it works fine with my MacBook.

I've ordered an AmazonBasics.

rlauriston · Post by **rlauriston** » Mon Dec 10, 2018 12:05 am

Can't get simpler than this.

https://www.amazon.com/Tablet-Stand-Adj ... B01DBV1OKY

Roger Linn Design

KVR Audio

LinnStrument 128 with USB-C iPad Pro