Part of the answer
CohassetMatt,
I can help you with part of the answer but since I have no experience with gear costing thousands I'll have to leave that part to someone else.
The important thing is that you like your rig on your vocals. Since you are not getting any noise hum or other obvious problems you are on the right path. To compare your preamps to other preamps you have to do an a/b test.
For instance the M-Audio DMP3 is a well regarded inexpensive preamp. $160 for two channels. I use the very similar DMP2 preamps. When I a/b compare my preamps in my Fostex VF160 against the DMP2 preamps on some sources, like vocals, they sound very similar. On other sources, like acoustic guitar, the DMP2 preamps are definitely superior with more detail and nuance appearing in the high end.
a/b comparisons are also useful in comparing two mics. Here's how you do it.
Record with the equipment you want to compare. Say mic A and mic B. Set them up so everything else is the same. Same quality cables, preamps, etc. Use the best quality of everything else that you can. Record the same performance to two tracks, one with mic A and one with mic B.
Be sure you are listening through good monitors too. Also listen through headphones but comparing only through headphones can confuse you.
To set up your volume levels pan one track hard left and one hard right. Adjust the volume so they are exactly the same in your stereo output. When comparing the tracks they need to be at exactly the same volume on your output meters.
Now set both tracks back to mono. With my Fostex I can punch tracks in and out with a switch that lights green when the track is playing and is unlit when it's not. Play one with the other off. Then punch them both at the same time. This will transparently switch tracks.
If you can't hear any difference your a/b comparison says they are exactly the same.
If you can hear a difference but you can't reliably pick which setup is playing without looking at the mixer the a/b comparison says they are very similar.
If you can reliably pick which track is playing without looking at the mixer the a/b comparison says they are different.
If they are different then it is up to you to decide which is better. If you have a clear opinion on this you have learned something about your equipment.
To compare preamps you have to use two identical mics. That means you have to a/b compare the mics first to know they sound identical on your rig in your studio. Just because they are the same make and model does not mean they sound the same.
Now for the answer to your bigger question. Read the Harvey Gerst sticky thread called Some Thoughts about "Better", "Best", and Mic Recommendations.
Many professional sounding recordings are made with inexpensive equipment. Many are also made with expensive equipment. Sometimes expensive mics, preamps, etc. are chosen because they sound better but often they are chosen because they reliably work with a large variety of sources and so they save time in the studio.
Thanks,
Hairy Larry
