17 Sep
2010
17 Sep
'10
10:32 a.m.
Philipp Überbacher wrote:
Excerpts from david's message of 2010-09-15
19:32:44 +0200:
jack2 on my non-RT kernel laptop has no jitter at all working with
UCA-202 connected to a USB2 port on the laptop.
Lower signal levels and noise when connected via my self-powered 9-port
USB2 hub. Cheap hub, probably very bad ground or poor shielding.
--
David
gnome(a)hawaii.rr.com
authenticity, honesty, community
Monty Montgomery wrote:
That usb hub stuff seems to be really strange. I do have an external
hub, but I only use it for HDs.
The USB interface is connected directly to one of the laptops ports.
The laptop seems to have an internal hub, or two?
Anyway, it works just fine, as far as I can tell. Some jack2 test I ran
showed quite immense jitter, but I guess that's normal with USB devices.
$ lsusb
Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 006 Device 002: ID 0582:0074 Roland Corp. EDIROL UA-25
Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Oh, I should say I've also just recently seen
similar problems (for no
apparent reason) when an XHCI (3.0) controller hands off a full-speed
(1.1) isochronous device. Is the port this is being plugged into a
USB 3.0 port ('SuperSpeed')?
Someone said something earlier about hubs. I
have a USB2 hub plugged
into a USB2 port on my laptop. When I tried using a Behringer UCA-202
(USB1.1) device through the hub, it could barely play, and not record at
all. Connected directly to a USB2 port, it plays and records fine.
So original poster just might be dealing with an internal hub.