Have you made sure the "settings in preferences" are set correctly?
1. No "sound check" and "sound enhancer".
2. Make sure "error correction" is checked.
3. No EQ. Turn it off, not just to "flat".
4. Use a good glass toslink cable.
5. Make sure the midi settings are correct. I think this is automatic with Snow Leopard, but you might want to check just in case.
6. Make sure all other apps are closed, especially browsers and other audio apps.
Hope this helps. A Mac can make an excellent digital music source.
1. No "sound check" and "sound enhancer".
2. Make sure "error correction" is checked.
3. No EQ. Turn it off, not just to "flat".
4. Use a good glass toslink cable.
5. Make sure the midi settings are correct. I think this is automatic with Snow Leopard, but you might want to check just in case.
6. Make sure all other apps are closed, especially browsers and other audio apps.
Hope this helps. A Mac can make an excellent digital music source.