Device powered by computer usb port but not USB phone charger

[mterry]

I have a Berringer U-Phoria UM2 audio interface, I use it to amplify a microphone input and split it between a headphone amp and a transmitter. I works fine when the USB cable is plugged into a computer, but fails to work at all when I try to power it from a USB outlet of a phone charger or power strip?
Any thoughts on how I can make it take power from the non computer USB source?

 

[davenn]

I have a Berringer U-Phoria UM2 audio interface

hi welcome to EP

I have no idea what that is
can you please show link(s) photos


Dave

 

[Harald Kapp]

I works fine when the USB cable is plugged into a computer, but fails to work at all when I try to power it from a USB outlet of a phone charger or power strip?

This interface is meant to be used as interface from the instrument to a computer. It is likely that the electronics requires connection to a computer to be set-up by the driver.

can you please show link(s) photos

See e.g. here: https://www.sweetwater.com/store/detail/UM2usb--behringer-u-phoria-um2

 

[mterry]

Thats the device. for my use I don't need the computer connection. It perfectly solves my problem when it is connected to the computed as a power source, without opening any driver or audio program. I guess I need to find a way to fool it into powering on without the input from the PC. adapter plug? or soldering iron attack?

 

[BrightLight]

Check out the usb cable. Does it match to the usb standart? Probably you'd find some trick in it.

 

[mterry]

I looks like a standard A type on the computer end, and B type on the device end
i'll have a look at it with my tester and see if the pin arrangement is normal

 

[Alec_t]

Check the cable to see if any resistors are connected from either data pin to either supply coltage pin.

 

[Harald Kapp]

without opening any driver or audio program

The driver is used without your having to install or activate anything.

i'll have a look at it with my tester and see if the pin arrangement is normal

It has to be, otherwise the device wouldn't work on a computer.

 

[Jarod997]

I know this is an old post, but I just did the same thing. 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 pretty strong evidence to support the USB Controller theory of how this thing is powered.

 

[Cosmin Postolache]

Hello, did anyone manage to make this thing work without the computer? Could you please share the appropriate hack?

 

[Jarod997]

This device shows up as an audio in device and an audio out device in Windows. That being the case, the only thing you might be able to do with this is try the hack I mentioned before with the D+ and D- lines and then you can use the headphone output in "direct" mode only (the push button, which IIRC says something like "low latency/lag" or "instant"). This is because it bypasses sending the audio out to the computer and then back to the headphone out jack.

I just ended up using it as a windows device - it works very nicely in its intended role.

 

[ramussons]

Hello, did anyone manage to make this thing work without the computer? Could you please share the appropriate hack?

Maybe the computer does the amplification part, the device maybe only a peripheral.

 

[Jarod997]

Maybe the computer does the amplification part, the device maybe only a peripheral.

No, there is an amplifier in the box, it's just that the manufacturers decided to make it a USB "device" in order to be able to get the audio into (and out of) the computer.

 

[ramussons]

No, there is an amplifier in the box, it's just that the manufacturers decided to make it a USB "device" in order to be able to get the audio into (and out of) the computer.

There is a "chip" in the box. How did you confirm that it is an Stand Alone amplifier?

 

[Jarod997]

There is a "chip" in the box. How did you confirm that it is an Stand Alone amplifier?

It is *not* a stand alone amplifier. It requires a computer or other device with a USB Host Controller to function. *If* you want to use it as a stand alone amplifier, you need to somehow trick it into activating and outputting a signal.

 

[Cosmin Postolache]

Thanks for your answers. Can you elaborate, please, on the voltage divider trick for the D+ and D- lines? I'm willing to try using it just for monitoring line level signals, which you can do by pushing the little "direct monitor" button.

 

[Jarod997]

Thanks for your answers. Can you elaborate, please, on the voltage divider trick for the D+ and D- lines? I'm willing to try using it just for monitoring line level signals, which you can do by pushing the little "direct monitor" button.

I don't recall the details exactly, and I can't find it online atm, but provide power and ground, then if you raise the voltage on the d+ line, you may trick the device into thinking that there's something connected. Just make sure you don't drive the D+ and D- lines past 5v. As it is a serial bus, the controllers send packets to negotiate connections and data. Holding the line up may make the amp think there's something connected and power on, or not - I don't know. Let me know what happens if you try it out.

 

[Harald Kapp]

I seriously doubt that manipulating the data lines will help here.
Most likely there are programmable components within the audio interface that need initialization code. The driver of the attached computer would perform this initialization upon plug-in of the device.

 

[Jarod997]

I seriously doubt that manipulating the data lines will help here.
Most likely there are programmable components within the audio interface that need initialization code. The driver of the attached computer would perform this initialization upon plug-in of the device.

I agree. It's unfortunate that you can't even power this device on without a USB controller.