Hi Tony,
I guess it depends on what you want to do on the computer as to what sound card you buy. Only very expensive cards will give you anywhere close to the KN6000 sounds so I used my KN6000 (before I traded it for the PR54) as my sound card when I played midi songs.
As for Singing and Recording to MP3 I recomend PowerTracks from PG Music. It's only about $29 to $49 and it does quit a lot.
Best Wishes
Heather
I have a 16 Bit Sound Blaster Live Card which I find to be fine for the things I do. SoundBlaster makes better cards now like the 24 bit Audigy® series but unless you are going to hook the card to a home theater I don't believe the extra cost is worth it.
Just be certain to purchase the midi connections for the sound cards game port.
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Heather- Leesburg, FL PR54