recording vocals and synths

i HAVE MPC 4000
SUPERNOVA
PC WITH TRUST SOUNDCARD(SUBJECT TO CHANGE) and cd burner
SHR58 MIC
AN OLD PRE AMP AND SOME SPEAKERS

I have sequences in the mpc 4000 that use the supernovas sounds.
Ive sampled vocals.i want to combine them with the sequences.
i think this can be done on the mpc but someone suggested syncin the mpc with cubase.but the post isnt really about that. How do i get all the sounds recorded . if i plug everything into the computer will i not be detractin sound quality ?
does anyone not use a computer ?
ill be recordin loads of vocals .i havent upgraded the memory . do i need to?
how do i get it so i can even hear the vocals and the sequenced synth sounds at the same time?
Just a tad confused. even a few examples of how yous do it would be great.

sup,

you could get a mixer(or sound card with enough inputs) to combine all your audio signals,
or sync up via midi and record them as audio to cubase,
or sample all sources and resequence them in your mpc,

Hths

thanks. i like the sound of the last one.
ill try that out.

what im doin is plugging my synths audio into the mpc and sampling it . Then samplin my voice while i play the sequence through my headphones. seems to work ok. then i merge the samples in the edit sample thing. is there a better way to do it. id have thought nstead of using 'analogue' option as the source for the sampling i could have used the Main Out to record the sample. doesnt seem to work . do i have to plug something inot the Main Out sockets.