Your soundcard has converters. Voice is not analog, per se...It's just a sound source. And the microphone is simply a transducer that creates an analog electrical signal, sends the analog signal to the preamp, stays analog through the Mackie and to the soundcard, where it is converted to digital. When you buy a high-end (stereo) soundcard, you're paying mostly for the converters in that card. That (and better connectors) separate pro cards from consumer or gaming cards. In most cases, a good quality audio card does just fine...If you're mixing a commercial record, you would want an external converter that will perform to the absolute highest quality. They shine most when it comes to stereo imaging and L/R correlation, which isn't an issue with voice. They also perform better on complex, dynamic material, which also isn't an issue with voice. Which is why a high quality soundcard will provide equal quality to an external converter, when used on voice. Someplace like a mastering house would use very high-end external A/D/A converters. They would also use cable that costs $400 per foot, and $35,000 monitors...Which is exactly what you would need to really hear the difference. Ever bought a $200 mic cable? It will make some difference, but only if everything else in the mic chain is flawless. Otherwise, it's a waste of about $170.
As for the Neumann digital mic, it's built for accuracy. It has A/D converters, which were designed especially for the mic, built-in. One would use the mic to avoid anything altering the sound of the mic. There's no preamp to give it color, no equipment or cable to distort the sound. After passing through the capsule, the signal is immediately converted to digital and transmitted to the DAW via AES/EBU or S/PDIF. IMO, it doesn't have much of a use...Measurement maybe. Might come in handy for symphony recording or something like that, where it's hard to keep the signal pure.
But to answer your question, no...You're fine. After you've dumped another $40,000 into your studio, then you might see the need....You know, after you've upgraded everything else as far as you can.
Emmett
