Mastering is one of the most important links in the chain of music production. Yet, it is probably the least understood. And it is rapidly becoming the most abused. You can be assured that no music is released by a major label or competitive indi label that has not been mastered

Analog -- It's All About Resolution

Analog has -- and always will have -- better resolution than digital, but it comes with the side-effect of sound coloration. When an audio signal is passed through physical elements such as tubes, capacitors and the like, they will impact the audio signal in some way. Even if a piece of equipment is on bypass, the act of routing a signal through it affects the sound. This can be a benefit or a detriment, depending on preference. Many people want what they call 

a "fat, warm sound." This is certainly an attribute that analog equipment can impart, but there are two other factors even more important in achieving this sound: the skill of the mastering engineer and how the music was recorded, as he/she can only work with what an artist delivers. Likewise, if a mastering engineer over-processes, even the best analog gear can sound harsh or muddy. Simply having a piece of analog gear in a signal chain is no guarantee of "analog" sound.

Digital -- It's All About Control

Digital -- with its ability to apply (and undo) unique changes to a virtually unlimited number of scenarios -- has greater control than analog, but it comes with the side-effect of lower resolution. However, keep in mind that "lower resolution" is a relative term. The 24/96 platform that many hi-fi enthusiasts proclaimed to be "as good as analog" has already been eclipsed by much better resolution rates. What we're talking about is theoretical resolution. Much of what is criticized as missing in digital falls into the "unheard, but felt" category: overtones and undertones that are beyond the scope of current sampling standards. In theory, digital will never have the resolution of analog. At a certain point, though, it becomes unnoticeable to the human ear.

Conclusion

So where does all this leave us? It depends on the application. In mastering, the ultimate goal is to apply changes to music that maximize its sound -- punchier drums, clearer bass, or whatever is desired -- without imparting any coloration from the process itself, while at the same time maintaining the highest resolution. In short, the perfect solution would probably contain the best elements of both analog and digital. Keep in mind, though, that either platform is just a means to accomplish work...not the work itself.

The best way is where there is both. The advantages in analog and advantages in digital, and putting them together.