I have an M50 as well, and I can use the VST editor fine. I guess it of course depends what it is you want to do.
To make sure we understand each other, the connection between the PC and the M50 is MIDI only, and as such does not carry any sound. If you want sound, you need to connect to the inputs of your audio interface. As long as that is clear, we're on to something :)
Then I have installed the latest version of the M50 editor (1.1.0), and I have also installed the latest version of the Korg drivers (I think V1.13, but I'm not sure). I also "installed" the driver for the M50. I have to admit, getting the Korg stuff to work correctly, confuses me too.
With "installed", I mean, once you have installed the driver, there will be a program called "Korg Midi Driver Setup Utility". Start this, and select your M50, then click install. What this does is actually configure the driver for windows. Without it, it is not really connected.
For the M50 editor, install the VST version in a folder so Sonar can find them (the default folder should do fine)
I have noticed that the best way to make everything work before you configure it in Sonar, is to also install the standalone version. Start that one, and let it sync with the M50. If all is installed correctly, it should work perfectly. To make subsequent starts a bit faster, I go to Utility-save and save it as DefaultNew.M50all. When that is done, I go to the global page, and choose utility - select auto load file, then the file I saved. It increases the speed of the connection a lot.
Then, to get it to work in Sonar...
I must tell you first, that I don't use the keyboard of the M50. I haven't gotten that to work correctly yet in combination with the Editor. I have a small UMX-250 and a MM8 that I use the keyboard from. If you want that, it will not (always) work.
Once Sonar is started (I use the x64 version), go to preferences, and make sure that the M50 midi devices are NOT selected. (so, they cannot be used directly without the editor)
Then, insert the M50 editor via the synth rack.
On the insert synth options, I choose only First Synth Output on the left side, and choose to open the window "synth property page". I leave the rest as it is, and press ok. (I tried setting the Midi output, but that doesn't seem to work 100% - YMMV)
It should make a connection to the M50 at that time, and sync all. Again there, I go to the global page, and select the auto load file that I created earlier.
Now, to get it to respond to Sonar, you need to put it in the SEQ mode. You can then, on the play page, set the different instruments you want for each channel. You could play with other modes as well, but remember you can only use one M50 Editor at the same time... So, you cannot use a second instance. Which is why the modes COMBI or SEQ are the most useful, and I found the SEQ the easiest to use.
Then, to actually have the instrument respond...
Create a midi track, set the input to whatever keyboard you use (or you can of course use the PVR or Step sequencer). Set the Output to your M50 plug in (it should be there in your list). Then, set the channel box to the channel of the instrument you want.
You can do the same again for other instruments, just change the channel on the midi track, and voila! You can use the Korg as you want.
Hopefully this helps someone... I don't know much more though... I am a beginner, reading the Sonar manual, and trying to get my head around the M50 editor...
I've also played without the M50 Editor. But, I haven't figured out fully on how to switch instruments using the MIDI instrument definition files. I have found an .ins file, but I can't get it to work 100% yet. If I have some more time, I'll try and figure out that one as well.
post edited by c5_convertible - 2011/08/17 14:59:34