Need advice on which sound card to use

I am using an FM Modulator to get the sound from my carputer into the stereo, and I'm having an awfull time finding a sound card that works well with this. I tried using the line out from the onboard ESS sound on the motherboard, but this must be a low poered line out as it required me to turn the volume way up to hear anything plus the sound was hollow. I tried using a SoundBlaster PCI 512 but because these cards do not have a line out conector (what's up with that??) the output was too weak to work. Finally, I've tried an old Crystal Audio ISA card I had laying around. This card has jumpers to select if the output should is speaker-out or line-out. This has proven to be the best so far, but because it's such a cheap soundcard the sound quality is not great (still sounds hollow). Can anyone recommend a good soundcard which has line out on it? I have tried hooking up a portable CD player to the modulator using the line out and it sounded great, so I think the trick is finding a sound card with a good line out on it. Any advice would be greatly appreciated!

Mike.

because you tried the portable cd player and it worked, my guess is that you need an amplified signal for the modulator. there are some sound cards that do have a jumper to select line out or speaker out. that is what you should look for--you can use speakers or amplified speakers--most basic copmputer speakers are amplified. also, the hollow sound could be coming from a bad ground connection. sometimes it sounds like that if you only use the r and l positives without the ground.

oh yeah--just set the jumpers to speaker out