The trick does work on the Roland A49. Any USB power source will turn it on. I have my A49 sitting right next to me and as always just now I was able to turn it on from a USB battery pack. One of the reasons I bought the A49 was because I "thought" from looking at the midi din out I could use it without a computer except that how do you power it with a PC??? That was when I found the trick on the net. It is not even mentioned in the manual. Just recently I purchased a USB MIDI host along with some other midi gadgets including a midi breath controller. The USB MIDI host, of course, will power the A49 no problem. Then I tried Samsung USB chargers and two different USB battery packs to turn on the A49 and send midi out. I don't like when manufacturers have features in their products that either they themselves don't know about or fail to mention in the manual.



When I got a Roland A-49 a few years back, I, too, thought it was stupid the A-49 could not power up as a standalone. I found a trick on the internet.

How do I power up my Roland A49 MIDI controller with a USB power supply (without a computer)?
Article #1725357 Added on Jun 8, 2015 at 2:16 PM
Hold the Function, Assign, and Pitch buttons while plugging the unit in to the power supply to enable the controller to receive power in standalone. Once you’ve done this, each subsequent boot should work normally with the power adapter without having to press that combination of buttons. [/quote]

That works? Funny... A normal USB power adapter apparantly doesn't work.
It's bizarre as I read the A-49 needs some kind of driver to work, either from PC or at least via iPad, but then that's obviously wrong...[/quote]