Altruist - Ok, now the picture is clear! You've got a very good soundcard and very good software, but the front end and back end suck. You said you've got a little money to spend......if you shop wisely you can fix this without it hurting too much.
Apex makes a dynamic mic, the kind you might hold in your hand while singing on stage, and some condensor mics that are much thicker, and you sing ito the side of it (side address) rather than into the end. If you have one of the condensors then you need to make sure you're singing into the correct side of it. It's not very obvious which side is the correct side, so this is an easy mistake, and will give you a thin sound. If you hve the dynamic mic then you might want to consider upgrading to a decent condensor mic. You'll find the difference to be huge, and suddenly every little sound, like just rubbing your fingers and thumb together, will sound amazingly clear and present. If you have, or if you get a condensor mic, get a pop filter to put in front of it. Without it you either have to reduce the preamp gain too low, or move too far away from the mic, giving you a thin sound, or every plosive (p's, b's) will jump out of the mix annoyingly. This will especially be true if you want to use the proximity effect of the mic to get a fat sound on your vocal. Proximity effect is a charachteristic of cardiod mic capsules where, as you get closer to the mic, the bass frequencies become more prominent.
Now let's skip to the back end, then we'll come back to the front end. Trying to monitor on a home stereo, even a good one, is a bad idea. You really should get yourself either a power amp and monitors, or get some active monitors. Active monitors have built in power amps, and might be the more cost effective solution.
Home stereo's all sound different, and are nowhere near flat. If you mix to one, your mix will sound like crap on the next one. You really need to hear the truth about what you're doing, and for that you need proper monitors.
Now, about compressors. Yes, you will almost certainly be happier with you vocals if you use some compression on them. But not neccessarily by buying a compressor and putting it after the preamp. Most engineers prefer to keep the original dynamics intact until mixdown, and then use software compressors to do the job. That way your not stuck with the compression you used while tracking. However, if you find that you can't get a good fat signal into the converters without going over Odb here and there and ruining the take, then a hardware compressor before the soundcard will fix things.
Ok, back to the preamp. I'm discussing this in what I think is the order of importance. If, or once you have a decent large diaphram condensor mic and pop filter in place, and proper monitors, then it's time to consider the preamp upgrade. Till then, the behringer will do the job ok. Yes, the Mackie pre's are much better, or there are several choices for standalone pre's that will give you a noticeable improvement over the behringer. Much has been discussed on the subject, and those opinions, plus your wallet, will guide you.
BTW, some DX or VST plugins will give you some nice compressors and reverbs to work with which will put the final touches on your vox.
Ok, there's my take on your situation, for what it's worth. Hope it helps with your quest.
Peace, RD
It can be subtle.
