In summary the issue is that the Fireface 400 does not output an audio signal after my system wakes up from Stand By. I've had this problem since I bought the unit.

OK, firstly let's have a look at my system details:

- Intel Core 2 Duo E6600 @ 2.4 GHz
- 2 GByte DRAM
- Asus P5W DH Deluxe motherboard (which I don't recommend, by the way)
- Windows XP SP2

- Fireface 400 + latest driver (v2.82) and latest firmware (v1.65)
- The Windows XP default playback device is NOT the Fireface 400

First let's prove that the Fireface 400 actually works:

1. Run Winamp and no other application that may attempt to use the Fireface 400.
2. In Winamp, Right-click > Options > Preferences... > Output.
3. Double-click DirectSound output v2.2.10 to show the DirectSound output settings dialogue.
4. From the list of available outputs, select Fireface 400 Analog (1+2).
5. Close all dialogues and hit the Play button to start playing some music.
6. You should hear it or at least you should see the input signal on the TotalMix level meters.
7. If you can't hear anything, tweak TotalMix until you hear the music.

OK, the above steps simply show that the Fireface 400 is indeed working. Now comes the fun:

1. Stop playing music and close Winamp. Open Winamp again, hit Play again and make sure you hear the music. Everything is fine, close Winamp yet again.
2. Put the computer to sleep (Start Menu > Turn Off Computer > Stand-by)
3. Wake up the computer.
4. Run Winamp again and hit the Play button.

This time you won't hear the music ALTHOUGH the level meter for playback channels Out 1+2 in TotalMix is actually showing that there is an audio signal on those channels. In addition, neither the level faders for playback channels Out 1+2 are not set to -infinity (in fact the state of TotalMix is identical to the state in which it was left before going into Stand By).

Now here is how I work round this problem. I discovered this by trial and error. Assuming that I have routed Outs 1+2 to physical outputs Analog 1+2:

- In order to get any sound out of Analog 1 I have to move, using the mouse, either the Pan control or the Level fader for Out 1 a little bit to kind of 'wake up' that playback channel. As soon as I fiddle with that channel's controls it wakes up and sound starts coming through the way TotalMix says it should.

- For sound to come out of Analog 2, I need to fiddle with the Pan control or the Level fader of Out 2.

In summary, the unit has to be awaken by performing this little workaround. Initially I was going mad because I couldn't figure out why I was getting no sound yet TotalMix indicated that sound was being output.

It is important to note that if Winamp had been set up to output on playback channels Out 3+4 instead, then the work-around would only work if you moved the pan or level controls for playback channels Out 3+4 (not 1+2).

Clearly this is NOT the way the Fireface 400 is supposed to work and will have a few scratching their heads.

Thanks in advance to all members who will participate in this thread and RME for their support.