From top to bottom: Preamps from Universal Audio, Manley, and Avalon.
A good mic preamp takes the audio signal from your mic and adds the punch, warmth, clarity, and presence needed for the source sound to really stand out in a mix. In fact, one of the first things I noticed when I integrated a high-quality mic preamp/compressor into my vocal chain was that I had to do much less fiddling with EQ and compression in the actual mix. This was a very pleasant surprise, not only because of the time I saved, but also because the raw vocal actually sounded better than I was able to get with even my best efforts using plug-ins.
TO EQ OR NOT TO EQ
While it’s fairly common practice to compress a vocal on the way in to your DAW, EQing the vocal at the mic preamp is a somewhat riskier proposition. The main reason for this has to do with the function of compression and EQ. At its simplest, compression brings up the soft sections of a vocal and tames the hot spots. Compression is something that, when used with discretion (I typically don’t use more than 3dB of gain reduction when tracking a vocal), is almost inaudible upon playback.
EQ on the other hand, colors the sound in ways that should be audible. That’s the point. The potential risk of EQing while you’re tracking is that you most likely won’t have the final mix together yet, and the EQ that sounds good while tracking might not be the EQ you need to sit the vocal in the mix. There are also whole schools of thought that recommend getting exactly the sound you want during tracking, so that mixing is essentially just bringing up the faders. While there is a certain freedom in doing things this way, you should really get to know your studio and your equipment before you EQ something during tracking.
AFTER THE FACT
Another valuable use for a high-end mic preamp/compressor/EQ is the ability to “re-amp” already recorded tracks by sending them out of your DAW into your preamp, and back into the DAW on another track. Now is the perfect time to try subtle—or even radical—EQ and compression because you’ve always got the original track to go back to if need be. More importantly, you can go back to any vocal track you’ve ever recorded, and add the sound of a great mic preamp.
READ THE MANUAL
This may sound obvious, but getting to know your preamp inside and out is the key to truly getting the most out of it. More often than not, the manuals offer not only the basics of the preamp, but also suggest ways to use it creatively. The manual for the Manley VoxBox—my mic pre/compressor/ EQ of choice—made a suggestion I’ll always be grateful for, and it’s one I’d have never come up with on my own. The VoxBox includes a de-esser (a frequency-specific compressor), which I assumed was only for taking the sibilance out of vocals. Instead, Manley recommended setting the de-esser to 3kHz to tame some of the piercing brightness that some female singers exhibit in that part of their vocal range. The result was that vocals I recorded using that application ended up sounding fuller and more listenable, and could even be brought up to higher levels in the mix—all while maintaining their warmth and clarity. So be sure to learn all about your gear, and don’t hesitate to experiment with atypical EQ and compression settings. You never know what you might get.