Hi, first of all, thanks for your detailed help. > You have two kernel drivers for USB MIDI devices. > * 'snd-usb-audio' is the ALSA module containing the drivers > for Audio and MIDI USB devices. > * 'usb-midi' is the OSS/Free module for USB MIDI devices > only. * 'audio' is the OSS/Free module for USB Audio > devices. You can have both modules compiled and installed, > but you should only use one of them at a time. ALSA does > not need the OSS/Free modules. It can do OSS emulation > using it's own resources. OK, very weird. Since I have installed Gentoo, ALSA never die restore the last settings of alsamixer. After every reboot, all channels have been down and muted. > Both drivers want to be loaded and claim the device if you > have hotplug installed. To "blacklist" one of them, insert > a line with the module name in the file > /etc/hotplug/blacklist. [...] Thanks a lot again. I blacklisted usb-midi, and now, after a reboot, alsa does not start anymore. I just telephoned with a friend, and we found out that the device was listed in /lib/modules/2.6.7-gentoo-r6/modules.usbmap so the module was always loaded after pluggin in the UM-1S. I removed the module file manually from the modules directory, and after a reboot, everything seems to be fine - even my alsamixer settings are restored! The presence of usb-midi and snd-usb-audio seems to have caused a really messed up setup. I'm just building a new kernel with all OSS stuff disabled (I really do not expect to need any of the OSS drivers), and I hope this will bring me a great success. Thanks for all of your hints, if I do any important and successful step, I'll keep you informed. Thanks a lot & kind regards ce