USB power output from Blue/Blackbox

[gradient]

Hey, wondering if it’s advisable to power devices other than MIDI devices via the USB out port on the Bluebox (or Blackbox)? For instance I have a reverb pedal powered via a USB ripcord from the Bluebox, and it seems to work, but I don’t really know if it’s a good idea to run it like that constantly.

and also...

Can the Blackbox play USB host to the Bluebox and supply MIDI+power to the unit? Or is that too much draw on the box? Again, I don’t want to stress these little guys out if it’s not advisable for long term use.

[jayneural]

You will most probably end up with ground noise issues.

I would say you may power something as long as it doesn’t produce any sound.

So controllers or sequencers will probably be the only suitable for this port.

[Solipsvs]

you should get a usb power consumption meter, theyre cheap and will inform you

[Aaron]

The USB device port is meant for lightweight peripherals in the 500mA and below category. If your reverb pedal fits this description, go ahead and power it that way. We don't recommend chaining a blackbox to a bluebox or vice versa using USB.

[sydilaxe]

I would also add that USB grounding is not the best and it often leads to hums and ground loops. I found that powering my Blackbox separately (or on a separate battery bank) from the rest of my USB powered gear (ie. NTS-1) will minimize or eliminate the noise or the need for USB isolators. When my Bluebox arrives, I will test running both the Blackbox and Bluebox off the same power bank, but I am anticipating noise/hum issues doing this.

[jayneural]

I have abandonned the idea personally. Tried NTS-1 on the Blackbox USB host port or even through the same battery pack and I get noise.

i don’t know how Roland manages USB host audio and MIdI on their MX1, but there probably must be some ground loop compensation or avoidance in the design.

I don’t know how the grounding can technically be overcome other than maybe creating a balancing mechanism to cancel the noise but it sounds like pretty sophisticated workaround.

I’ve always been dreaming of a merge of the MX1 and Bluebox, in other words a smaller MX1 with great UI and USB host ports accepting class compliant midi/audio.

How cool would it be to have an ecosystem where most of the synth connect and get power through a single wire...

[DanDay]

Just to report on the topic. I have connected the Keystep Pro on the USB Device port and use it both for MIDI (sync) and power supply. Seems to work. No noise issues so far.

[jayneural]

There should not be any problem as long as the device connected on the host port don’t generate sound. That’s why it’s made, for MIDI controllers/sequencers.

[DanDay]

Just an update, unfortunately the Keystep Pro seems to take to much power from the USB Port. The bluebox had a freeze after some more time.