Loss of MIDI communication when I connect RK-008

adacey

I'm sure I'm missing something blindingly obvious, but I'm stumped.

I've connected my RK-006 to a USB hub using the OTG cable. I have a mix of gear connected to the USB hub via the TRS ports. Everything works fantastic with the RK-006 acting as the USB host. If I play notes on my MIDI keyboard (connected and powered via USB) I see the ports on the RK-006 light up and can reliably switch MIDI channels to communicate with each synth.

But as soon as I plug in my RK-008 to the same hub everything seems to fall down. The RK-006 starts blinking, presumably picking up the RK-008 as a clock source. But now if I start playing notes on my keyboard then no device (either via USB or TRS) seems to receive the notes. I do see the route light blink on the RK-008 as I play the notes. If I turn on the Route mode then the RK-006 ports blink again but I don't get the notes on the other USB device.

It almost feels like as soon as I connect the RK-008 the RK-006 starts sending all of the MIDI events only to the RK-008. I could be misunderstanding something, but if I'm playing on a given MIDI channel shouldn't the device that's listening on that channel still receive the notes as well as the RK-008?

adacey

I may have found the answer to my problem. https://bla.retrokits.com/flarum/public/d/182-rk-006-maximum-number-of-usb-devices-in-standalone-mode talks about the RK-006 only handling 4 USB devices. I'm using a 10 port USB hub so if that's divided into multiple hubs then that could easily explain things. I'm wondering if the RK-006 is switching to whichever hub the RK-008 is on as soon as I connect it because it starts to see a clock signal from the RK-008?

I'll have to do some more experimentation to figure out which ports are on the same hub to see which combinations will work. Worst case, there are only a small number of devices that I really want/need on the USB bus so I could shift everything else over to the TRS ports and probably be fine.