I didn't really find anything, about this in this forum, so I decided to write about it, and later on, I'll upload a video about setting up an online radio station.
You can also use, the U-Mix Control Pro's internal sound interface, but I just want to give an idea.
Things you need.
A a DJ software ASIO compatlible (ASIO only on Windows)
Winamp (free, or pro, doesn't matter)
The latest Shoucast Plugin for winamp
A radio server with the following things: ip, port number, username, password
A good internet connetcion (minimum 10 Mbps is stable)
Optional: Mixer
I know only how to do it on Windows (same on XP and Win7), but hopefully the same on Mac-s.
Step 1.
Install all the software mantioned, and also the Shoutcast tool for Winamp.
Step 2. Once you're done, connect the U-Mix 44 soundcard. Run a few tests.
First: Open the DJ program you use. Play some music an all the decks, and make shure everithing is OK on the output, and the card is ACTUALLY USING the ASIO driver!
Second: Close the DJ software, and open winamp, and test that you can play through it as a standard souncard that Windows uses as Default!
Step 3. Set up your broadcast system. I suggest to minimun use a 2 channel DJ mixer for the process. With this, your DJ software should be set, to run you mixer channels for example: (Mixer Line 1 to soundcard output 1 & 2, Mixer line 2 to soundcard output 3 & 4).
Then, plug in a Microphone into the mixer.
Finally connect one of the main outputs to Input 1 & 2 of the U-Mix 44. it is IMPORTANT to be able to ADJUST the mixer out level with the mixer, because U-Mix 44 is sensitive on inputs.
Then you plug your headphone, and/or a monitor speaker system, and you are done!
Working the station:Setting up Winamp:
Step 1.:
First open Winamp as an administrator. Go to Options / Preferences. Scroll down to the Plug-in sectgion, and choose "output" on the left, and then choose "Nullsoft wave output" of the right. Set the output soundcard to the built in soundcard of your PC, and click OK, then close the preferences window.
Step 2: Whene you open winamp, with the SHOUTcast plugin installed, a small window should appear with it, that says: Nullsoft SHOUTcast Source.
Click on the Output tab, and choose Output 1 from the list. You'll see 3 other Tabs: "Connection", "Yellowpages", "Encoder"
First get to the "Encoder" tab, and choose the Encoder type, and bitrate.
Then get back to the "Connection" tab. Type in the broadcast server IP, Port (Stram Id should remain on 1), and underneath that, the username and password. If the server is turned on, and every data is ok, press "Connect" button, to test the link. If everithing is all right, youll see a counting number in the Status bar, above the "Connect" button.
IMPORTANT: The Firewall must be set, to let Winamp through.
Step 3: Open the "Input" tab. You'll see a level meeter on the right. Set the Input Device to "Soundcard Input", This will set U-Mix 44 Input 1 & 2 as an imput source. Anything you connet to that, shall affect the level meter.
Note: You may need to restart Winamp after you have set everithing.
Streaming:
Step 1.: Close every programe on your PC. Fist open Winamp, and then open the DJ software. Every setting is stored. Put on some music and start playing.
While the music is playing, check the Winamps Shoutcast tool, and go to it's "Input" tab, to see the Level meter. You'll see,the level high and changing, when playing. If the level contantly on 0 dB, lover the DJ sowtware output, or the mixer output level, until, the highest level is -2 dB and the level meter soud dinamicly change as the music goes.
Step 2.: Get the playlist file of your online radio. You can get it, from your servers admin page, by logging in on the server host website.
Open the playlist file in winamp. But don't start playing it yet.
You are ready to start broadcasting. By clicking on the connect button, the stream begins, to se stream server.
Checking stream sound quality and level: Play the steam playlist file on Winamp, and listen to it with on the built in soundcard of your PC (set before). You'll hear, if anything is wrong.
This is how should everithing look like, connected to the sever, music playing, and streaming back:
Continue Broadcasting, till you get sick of it
To and the stream, simply press diconnect on the Shoutcast tool.
DONE!
For Questions, feel free to ask.
c00l People MV Society 
