There are two microphones to be recommended, the C 520 and the C 555
The C 520 is an excellent sounding mic for singers and announcers, the C 555 is a more affordable model designed for speech applications.
The sensitivity of the C 520 is 5 mV/Pa, which should be enough for an average sound card. The C 555 has a sensitivity of 35 mV/Pa, 7 times that of the C 520 and certainly more than enough to drive a sound card.
Although technically speaking, both of the above microphones will be able to drive a sound card, the audio quality of the output signal of most sound cards will be far below professional standards.
Note that the microphone signal is measured in millivolts while the various voltages present inside the computer (including all the noise spikes, etc.) are measured in volts. Therefore, it is very easy for the electrical noises inside the computer to interfere with mic level signals on an audio card.
Especially with the C 520, to get the best possible audio, use the PP version with a microphone preamplifier with built-in phantom power. Such a preamp will provide the voltage necessary to power the mic and boost the low-level mic signal to line level so it will work much better with your computer sound card. You should be able to get a very quiet, good quality preamp at your local big box music store at a modest price. The result will be dramatically improved audio to drive your computer.
