We have found some problems with USB 1.1 devices attached to non-root USB hubs on Windows 7. The cause appears to be a problem in the way Windows handles non-root USB hubs.
Some of the symptoms of this problem are listed below:
- Interface fails to stream audio at low buffer sizes (below 3ms).
- Device fails to connect when other USB 1.1 devices are in use and connected to the same non-root hub.
- It's not possible to use other USB 1.1 devices when the 6 USB is connected.
- Device shows in device manager (under 'Sound, Video and Game Controllers') but doesn't appear in Windows' sound preferences.
- Streaming of Windows sounds is possible but the Focusrite USB ASIO driver gives an error message when selected.
- Audio is glitchy or does not pass. Playhead on programs may not move.
Whether a device is connected directly to a USB root hub or Generic USB hub can be found in the Device Manager, found in the Control Panel. You should then choose the option 'Devices by connection' in the 'View' menu.
If it is correctly connected to a USB root hub it will appear like this:
If it is incorrectly connected to a generic USB hub it will appear like this:
This is particularly prevalent on the new Intel i-series chipsets (Core i3, i5 and i7), both in desktop and notebook format, as these chipsets do not provide a way to connect directly to the root hub.
We suspect this is the new way the Motherboard connects all USB 1.1 and USB 2 devices to the same chip, where on previous computers these had two chips.
There are a few possible workarounds that may assist you.
Try connecting to a USB 3.0 port on your computer, as these will not have any Generic Hub. This may or may not work depending on the port and it's backwards compatibility.
Desktop users can add a PCI or PCIe USB card, which will work as long as the card does not have an internal, non-root hub. A USB 2.0 or 3.0 card may work, depending on specs.
Notebook/laptop users cannot add a USB 2 ExpressCard, as these cards attach a new hub to the existing USB controller and you still cannot connect directly to the root hub. In this case, a USB 3 ExpressCard can be added provided that you are using the latest drivers from our downloads page.
***A new work around we just discovered is that in some cases connecting a USB Powered Hub to the same USB 2.0 port that has the Generic Hub may cause proper pass through. This worked on on a few computers we have seen. While the unit was still connected to the Generic Hub this solved the issues of audio glitching/crackling/droping out. This may be due to how the onboard Generic Hub is downconverting from USB 2.0 to USB 1.1. Using an external powered hub would move this conversion from the onboard hub into the external hub.
If you have any further issues please Contact Tech Support.