Mark Knecht wrote:
On Sun, May 1, 2011 at 8:33 AM, Arnold Krille <arnold@xxxxxxxxxxxxx> wrote:
On Saturday 30 April 2011 23:33:24 Mark Knecht wrote:
One other consideration is device power. This will be hooked to a
laptop and I'm not sure my laptop supplies SUB bus power.
Additionally, I don't know how to test that myself. It seems from
looking at the Roland site that there isn't a power connector on the
UA25 so it's possible it wouldn't work, or maybe would require some
sort of a USB hub that can supply power.
If your laptop has standard-conforming usb-ports, they will provide the power
needed (and spec'ed in the standard).
I'm not saying they don't supply power. I'm only saying I don't know if they do.
If it turned out they didn't, for whatever reason, then the purchase
of a bus-power only audio device would be a disappointment.
Actually most laptops tend to supply more then the max of the spec. The reason
behind this is that many external hdds need more then standard power and thus
use two connectors. But on laptops both of these would be on the same power-
supply anyway and physical ports are notoriously short. So they provide more
power and make most hdds happy when connected with just one connector.
Have fun,
Arnold
In both Gentoo and Win 7 I have hooked up all 4 external USB hard
drives that I own to the ports and none of them worked. Using your
info about power that implies that none of these drives can be powered
from the bus.
I have 1 external USB hard drive, it works fine hooked up to a single
USB2 port on my Toshibas. It contains a 2.5" notebook hard drive.
I've been told that external hard drives that use desktop-sized 3.5" or
larger hard drive technology require more power than the USB port alone
can provide. Most such drives I've seen came with external power
supplies, or special USB cables that used 2 ports to provide power.
--
David
gnome@xxxxxxxxxxxxx
authenticity, honesty, community
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