Device powered by computer usb port but not USB phone charger (U-phoria UM2)

[jh_bach]

Hello, just joined to the forum because I was looking for a solution for same problem mterry highlighted. I have U-phoria UM2 and I want to use it without laptop, just need to connect to a powerbank because I'm just interested to mix 2 signals. What is the solution on mterry issue? I cannot found solution in the forum...

This post is moved from this old thread:
https://www.electronicspoint.com/fo...er-usb-port-but-not-usb-phone-charger.288982/

 

[Harald Kapp]

According to the manual the UM2 should work with a powerbank. Did you use the original Nitecore cable supplied? Does the UM2 work on a laptop but not on a powerbank?

 

[Jarod997]

I just posted on the original thread, but I'll recap here:

I bought a UM2 for a non-computer application not realizing that the device was *only* USB powered. It powers on when plugged into a computer, but not a wall charger.

I have a ticket in with Behringer, but so far no luck.

There may be a voltage divider hack on the D+ and D- pins on the USB line which will make the device power on, but I don't want to hack it yet if I don't have to. The other possibility is that the device will only power on after it receives a data packet from a USB controller (eg a computer).

*lightbulb* I just discovered my VoIP phone has a USB port which must have a controller in it, and it works to power on the UM2. This is significant evidence to support the USB Controller theory of how this thing is powered.
​

Back to @Harald's point, the Powerbank may have a USB Controller in it, whereas a "power block" (eg just a simple plug in the wall USB charger), even a 2A rated unit, doesn't - and won't power on the device.

 

[Jarod997]

So, for clarity, here's a brief list of what does and doesn't work.

Does:

• Computer (Windows & Mac, desktop & laptop)
  
• Yealink T46S VoIP Phone

Does Not:

• UPC Surge Protect power bar
• TPA-46050200UU - 2000 mAh USB wall charging "block"

 

[Jarod997]

According to the manual the UM2 should work with a powerbank. Did you use the original Nitecore cable supplied? Does the UM2 work on a laptop but not on a powerbank?

The only thing I see in the manual is the following:
https://drive.google.com/file/d/19sghp0MiunENpMYdKqy8YqvOoyF9FZtC/view?usp=sharing
Which doesn't say anything, really.

 

[Jarod997]

So here's my last post about it. From what I've been able to figure out myself, this device is not a stand-alone pre-amp, it's a "sound card". It requires an OS to use it as an input and output sound device. (The two are separate, which is why there's a toggle on the front for "direct monitoring".)

In the end, it turns out I don't need to use a pre-amp - but I thought I'd publish my findings for others.

I hope it helps.

 

[Harald Kapp]

Thanks for the update.