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Another audio question

WoodrowA asked
I posted a question similar to this last week and thought I had the problem solved, but apparently not.

I have an external audio device I connect to my Windows 8.1 Inspiron 3847 desktop.  This is a Technics keyboard (actually taken over by Panasonic).  I connect it to my machine because I am a music notation copyist and use music software.

I have discovered that the USB device is only recognized by my system under certain conditions.  First of all, the device was made prior to USB 3.0 so I plug it into a USB 2.0 port.  But to my surprise, which USB 2.0 port I plug into make a difference.  That is, if I plug directly into a port located on the front or back of my machine, it will not work.  However, I have what I guess you call an extender four port USB hub. I plug it into one of the USB 2.0 ports of the computer and it gives me three additional USB 2.0 ports.  

For reasons unexplained, when I plug my audio device into it, it gets recognized. If I plug it into any of the other on-board USB 2.0 ports on the computer, it does not.  Go Figure?  The only thing I can think of that is different is that the extender,  has its own power supply.  The error message when plugging into ports (other than on the extender) says "The last USB device malfunctioned and windows does not recognize it.  

Anyone know what might be going on?
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Most Valuable Expert 2014
I have had problems with USB devices that get their power from the USB port.  Not all ports and especially front panel ports on older computers will provide enough power for the device to operate.
I will second that one.
It sounds like it dosen't like the limited amps the onboard can supply, where as the powered hub can feed it more.
Top Expert 2013
the usb power is limited to 5 V at 0.5 A Max = 2.5 W
However, not all boards provide the max, so it is possible that the external hub just delivers a bit mor e power

Does it also NOT work when plugged into an USB 3.0 port?  it should work there - if only power is the problem, since these ports supply more power


Thank you all for responding.  

I only have two USB 3.0 ports and I have not tried the device on them.   It is not clear to me how well things that were made for USB 2.0 actually work in a USB 2.0 port.  But I have discovered two things.  One, the external device with its own power does seem to make a difference, and two, I had a very long USB 2.0 cable I was using.  It worked using the extended port, but not in the front USB 2.0 port.  However, I found another cable (shorter) and it seems to work well in both.

This brings up another point in that it seems that all cables (that look like USB cables) are not created equal.  It's a complex subject.  I wish I had a better understanding of it all.  Is there one type of USB cable you can and or should buy these days, that you can be relatively sure will work in a variety of circumstances?

Would there be some value in purchasing a USB 3.0 Hub with it's own power supply,  Is there a point in time where you can just have too many hubs?

Thank you again
.. ...a very long USB 2.0 cable

That makes sense. So it's not that your onboard ports didn't make enough milli-amps to run your device, you were losing just enough milli-amps to resistance in the longer cord.

>> ...one type of USB cable you can and or should buy these days,

not really, but I try to stay away from the really thin ones, when possible.
And cables with the whatdoyoucallits (about the size of a C battery) on them are arguably the best.

>> ...be some value in purchasing a USB 3.0 Hub...

eventually. But I would wait until you actually need one. There has been some minor issues running USB 1 and 2 devices on a 3 hub.
In theory, it's suppose to be backward compatible, but sometimes manufacturers "tweak" their device specs, so things don't always play nice, like they are suppose to.

>> ...where you can just have too many hubs?

uhhhh... yes and no.  
The USB spec allows for 127 devices.  So no
You will probably never need that many devices hooked up, and Windows will probably gag on them, way before that. So yes.   ; D
Top Expert 2013
>>  It is not clear to me how well things that were made for USB 2.0 actually work in a USB 2.0 port.    << what do you mean with this??

>>   It worked using the extended port, but not in the front USB 2.0 port.  <<  that's because the front ports are connected via a tiny cable already - limiting a bit the current (they are in fact not intended for usb power devices, like disk drives; more for an usb stick and such)

as for the type of cable to buy, look for big cables, not the very tiny, and very flexible ones; they usually carry less current

an exerpt from the usb Wikipedia page :
The USB 1.1 standard specifies that a standard cable can have a maximum length of 5 meters with devices operating at Full Speed (12 Mbit/s), and a maximum length of 3 meters with devices operating at Low Speed (1.5 Mbit/s).[78][79]

USB 2.0 provides for a maximum cable length of 5 meters for devices running at Hi Speed (480 Mbit/s). The primary reason for this limit is the maximum allowed round-trip delay of about 1.5 μs. If USB host commands are unanswered by the USB device within the allowed time, the host considers the command lost. When adding USB device response time, delays from the maximum number of hubs added to the delays from connecting cables, the maximum acceptable delay per cable amounts to 26 ns.[80] The USB 2.0 specification requires that cable delay be less than 5.2 ns per meter (192 000 km/s, which is close to the maximum achievable transmission speed for standard copper wire).

The USB 3.0 standard does not directly specify a maximum cable length, requiring only that all cables meet an electrical specification: for copper cabling with AWG 26 wires the maximum practical length is 3 meters (9.8 ft).[81]

if you want a longer length; use a booster, or repeater


Thank you

Thank you much.    : )