somehow my earlier post got lost. Basically, it is mic then pre. A solid pre will help any mic, but if the mic ain't working for you to start with it won't help. I'd look at a new mic first. Guitar cab is a 57 for rock hard stuff or a ribbon for a mellower sound (can still sound nasty, but more of a vintage thing). I've been using the mxl 141 or whatever lately here at home. Sub $100 and it sounds really nice tone wise, but I imagine metal would be captured better by a 57. And vocals are always a personal thing. Each mic is a little different and each voice more so and ear, too. I can't really offer a suggestion other than an large diameter condenser is usual on voice except for the smb7, which gets used a lot. there are too many mics and the choice is too personal. IF you could spring for $1000 and a bock fet you would have a great all purpose mic.
pres help a lot, expecially w/ the smb7 which needs a lot of gain. the warm audio or new tone beast are great preamps, price or not. The isa one or gap are both good transformer preamps which will give plenty of gain. The warm isa and gap are all about $400 while the tone beast has different transformers as well as op-amps available inline and is very flexible as well as solid at $600. Prices go up from there and you get a little more umph, but any of those should work and you'll keep even if you can afford a vintage neve. Transformers are the key, imho, adding a certain roundness to digital recording if you grew up listening to older, analog recordings. And a good transformer (just one) costs like $75, and most of the high-end preamps have at least 2 (in and out).
But mic first - a good preamp will enhance that sound and give you more mic'ing possibilities and overs, etc. better.
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