From: bart@xxxxxxxxxxxxx [mailto:bart@xxxxxxxxxxxxx] >> I don't find the DDK say we can't use PortCls to implement USB Audio >> Driver. >You can do it, I also did :) What happens when you surprise remove your device AND a stream is running? The device object remains; it is not destroyed. This causes lots of problems if you try to connect and use the device again without rebooting :( If you found a solution to this, I'd be glad to hear about it. Mat ****************** WDMAUDIODEV addresses: Post message: mailto:wdmaudiodev@xxxxxxxxxxxxx Subscribe: mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=subscribe Unsubscribe: mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=unsubscribe Moderator: mailto:wdmaudiodev-moderators@xxxxxxxxxxxxx URL to WDMAUDIODEV page: http://www.wdmaudiodev.de/