Hey, Dank, just so you have complete information, you should know that it is possible to get break-up (distortion) at the mic before the signal even reaches the preamp. If you use a condenser mic with a pad (a switch that says something like 0, -5, -10) you may need to experiment with that. Obviously, 0 gives you the strongest signal but with some singers you need to attentuate (pad) the mic. For example, with my Rode NT-2A (a common good but not expensive condenser), I use -5 when I sing but -10 with a female vocalist I record often. Even if you don't get serious distortion, the sound can be hard or brassy if the mic is pushed too hard.
You also need to match the impedance of the mic and the preamp, if you have that option. For example, I have a Eureka rack-mount channel strip/pre I use sometimes and it has an impedance selector switch. I looked up my mics online (since I couldn't find the manuals!) and noted the impedance of each so I could get the best match.
Finally, you need to make sure the phantom power on your pre is ON for mics that require +48 and off for those that do not. (Some pres only offer +24 which is odd.)
My apologies for taking your time if you know all this already, but I had to learn a few things the hard way and hope to spare others when I can.
Final note: I find it very frustrating that there is no input level control in Sonar. In older "traditional" studios with tape machines and analog mixing desks, I was used to riding the fader somewhat during recording. I miss having that option, although I don't want to sacrifice the obvious advantages of DAWs.