Trouble with Plantronics 478 USB headset

[Corinna Vinschen]

Hi,


I purchased a Plantronics Audio .478 USB headset for using under Fedora
18.  The headset is recognized at once, but I have trouble with the
remote control in the cable.  There are three buttons, "+" and "-" to
control the headphone volume, and one to mute the mic(*).

The problem is that the buttons only work exactly once after plugging in
the headset.  If I press "+", even only for a short time, the volume
level goes up and up until it hits the maximum level after a couple of
seconds.  Pressing "-" afterwards has no effect at all.
If I press "-" after plugging in, the volume goes down to 0 and sticks
there, no pressing of "+" can change that.
The "mic mute" button works only once, too, and afterwards there's no
way to unmute the mic, except for plugging off the headset and plugging
it in again.

The audio control appears to broken as well.  After pressing "+ or "-",
if I try to change the volume in pavucontrol, it changes to the one I
chose, but then fades either up to max, if I had pressed the "+" button
before, or it fades down to 0 if I had pressed the "-" button before.

Does anybody know if there's a solution to this problem?  Using the
volumes and mute buttons is kind of essential when in a conf call.
Or do I have to return the thingy since it's known not to work right
under Linux?


Thanks,
Corinna


(*) There's a forth button, but it only works with sepcial software
    under Windows or Mac, afaik.