Jim Dixon and I have had disapointing results with USB hubs during the testing of USB fobs with them. We don't know why they don't work properly and we don't have the time to figure it out right now. There may be hubs which work just fine, but we just don't know as the root cause of the problem has not been uncovered. If Steve Henke W9SH knows something I don't them maybe he should speak up on the list. Steve WA6ZFT
The problem is probably complex. USB 2.0 hubs come in two flavors single- transaction translators (single-TT) and multi-transaction translators (multi-TT). Most USB audio devices are "full speed" devices (12 mbits/sec), not "high speed" devices (480 mbits/sec) so the USB hub must translate the data rate between the host and the device. The single-TT devices only have a single translator which is shared between all ports. A multi-TT hub has a translator per port. So in theory a milti-TT hub is what you should want for optimal bus usage. An additional complication is that the Linux kernel must be multi-TT hub aware to properly schedule things. I'm not current with Linux development, but I've read discussions in the past about improving the kernel's USB scheduler in this area. Here are a couple of links to info which may be useful: http://www.commsdesign.com/design_corner/showArticle.jhtml?articleID=1650536... http://www.linux-usb.org/usb2.html 73's Skip WB6YMH