a preamp is the device that pre-amplify the mic signal to line signal so it can be handled by devices like audio-interfaces, mixers... However, mixers and audio-interface have in-board preamps (the things with an input gain knob). But a audio-interface preamp like m-audio ones are decent but the quality can't be compared to external preamps which cost the same price or more, cause an audio-interface has 1 or 2 preamps, A/D converters...
It's hard to give advices for a mic, cause it really depends on each singer. And generally, we don't choose a mic on its own but a combination of mic+preamp, cause certain mics work better with certain preamps, and vice-versa.
Personnaly, I prefer a good dynamic mics (there are more accurate mics than SM58) over cheap static mics like t-bones (I have a tube t-bone). Static mics are harder to handle (good positionning, headphone, needs good preamp to sound the best)...

hey seventhson (of a seventh son) up the irons ;)
thanks for your helpfull reply :)
my audio interface has got one knob for mic input, one for guitar input
and one for output! so does it make sense to get a pre amp?
your command about mics was really enlightening haha why didn't I think
of that one!!! so I guess the m audio mic would be a good choice, right?
When it comes down to me as a singer, well...... I am a good singer who is
constantly getting better and better! I am currently teaching my vocal folds
get into head voice! I have been trained by oiselle, still am in training
and actually I wanna be able to sing anything and I am processing quickly
so a multi-talent microphone would be great!
Do you know such a microphone?

greets! thank's for ya help :)
René

I have a M-Audio firewire audio-interface, with the in-board preamp and a dynamic mic a little more accurate than SM58 (Shure Beta58, AKG D5,D7, Blue, Sennheiser, Audix...) you can get decent recordings.
If you want a little more clarity, maybe you can try some live static mics (Akg C5, C7, Blue, Shure Beta87...) they are less expansive than studio statics mics and are easier to use (room, monitoring...).
It really depends on your budget, but for a real upgrade, you have to pay at least 300-400€ for the static mic and more than 500€ for a preamp.
As I said, you really have to try different preamp-mics combinaison depending on your voice and what you're looking for. Some mics are flat, other has extra clarity... some preamps are modern and straight, others are "vintage" and add warmth...

Hey Seventhson!
My budget is not really high so I think the beta 58 would be a great choice.....but I already have a sm 58....is the difference in sound quality really so dramatic that an upgrade to the beta 58 is absolutely necessary???
My m audio fast track mk2 interface has got an inboard pre amp just like yours! So would it make any sense to buy another pre amp....well, would it make any difference to the sound quality?
If so, how can I connect that pre amp to my audio interface??

It's hard to tell on the internet how much it will improve your sound to use this mic or that preamp!
Depending on what you are looking for, a more expansive preamp can give you more warmth, better clarity and definition... and the same for the mic.
Of course a twice the price equipment will not improve twice the sound.
As far as I am concerned, I think it would not be a good thing to buy a good preamp and to use it with live-mics like SM58 or Beta58.
For a home studio substantial improvement, you'll have to consider around 300€ for a mic and 500€ for a preamp.
With an external preamp, you have to connect it with a jack in a line input of your audio-interface.
If you can't afford to pay 800-1000€, and you don't want to have studio static mics contraints(monitors, room, positionning...), maybe a first piece of improvment for a little more definition could be a live-static mic, for instance :
http://www.thomann.de/fr/akg_c5.htm
http://www.thomann.de/fr/ev_re410.htm
http://www.thomann.de/fr/blue_encore_300.htm
http://www.thomann.de/fr/beyerdynamic_tg_v56c.htm
http://www.thomann.de/fr/sennheiser_e865s_evolution.htm
http://www.thomann.de/fr/audix_vx5.htm
http://www.thomann.de/fr/shure_beta_87a.htm
there are more expansive other mics (Neumann...)

@Seventhson

That's all nice and well but it's really not worth shelling out for expensive equipment when chances are he's not getting everything out of what he's already got already.

It's extremely easy to make an expensive condenser mic on a good preamp sound like a 2 quid mic.

that's exactly why I said that there are contraints using studio condenser mics (positionning, monitoring, room reverberation, coupling it with the good preamp...) and that if he can't afford this, to gain a little more definition he can begin with his audio-interface preamps and a condenser live mic under 200€, which will bring a little more definition and clarity than a SM58.

@moshmetalvocalist

If you could send me a dry vocal track and the same one wet with any effects you use, it'd be brilliant. I can have a look to see where the problem lies, the quality of the initial recording or what.

hey alkis!
thank you so much, that's really kind!
of course I can send you two recordings!
Could you give me your email?
thank's man!
Rene

Hey

it's amigr667@gmail.com

I used to do shadow boxing to music. I'm not the best singer, probably a little bit worse than robert lunte.

I know you did :) When I was younger and not such a good singer as I am now I loved to cross my legs behind my ears while having my hands in handcuffs and eating spaghetti to the rhythm of the music.....that was fun :)

Thank´s man! Hotmail seems to have some server issues and I can´t enter my acount right now so I am gonna send you those two records later :)