soundcards as applied to the 6000/6500/7000? just refer to the ew01, ew02, and ew65(special case 6000 upgrade only) add on boards that slot into the inside of the keyboard.

they contain an extra 16 MB of new wave rom (each one extra 50% for 6000, extra 33% for 6500) with new samples not present before.

2 slots are available for them in 6000/6500.

these new voices appear in new screen buttons in the sound explorer, each having a new explorer menu system like a smaller version of the existing main sounds. They are colour coded blue and yellow so you can see where the sounds have come from.

the new sounds can be used anywhere in the keyboard just like the existing sounds, and the samples can be mixed in sound edit with the existing samples normally.

the 01 and 02 have around 200 new sounds each, depending on how you count drums and vocal patterns at different tempos.