Some people would say "a microphone is a microphone," but that's like saying "a guitar is a guitar." The truth is there's a big difference between the various kinds of mic, just as there is between individual instrument models. And speaking of guitars in particular, there's one more thing that microphones have in common with guitar amps: to get the warmest, richest sound, there's no substitute for tubes. It may seem like dated technology, but by the same token, it says a lot about MXL tube microphones that no newer type of circuit has been able to match their acoustic qualities. If you're looking for a mic that has no equal, you've come to the right place to find it.
The biggest practical difference between these tube mics and their more common tubeless cousins can be summed up in one word: personality. Each and every tube has its own unique character. For instance, the Mullard 12AT7 tube in the MXL Genesis Studio Tube Condenser Microphone is known for combining clean highs, warm mids and a tight low-end, with oh-so-satisfying results. In tube manufacturing, it's also common for subtle differences to give each tube its own personal color, even compared to other tubes of the same type - which makes them perfect for experimentation.
To show the versatility and customizability of MXL tube mics, a good example to look at would be the Revelation Tube Condenser Microphone. With the ability to swap in different tubes, it's like multiple mics in one... though there's a good chance you won't even want to change it, since the included EF86 pentode tube is hand-selected to deliver the ideal balance between intimate warmth and punchy clarity.
Reading up online about tube mics is an interesting experience - you'll find that there are lots of professionals who swear by them, and others who would rather not use them. That's exactly what you should expect to read about any microphone, because each type has its own qualities that appeal to certain types of artists. So, ask yourself what appeals to you: if the answer is rich sound with lots of character and a mic that can be whatever you want it to be, then MXL tube microphones belong at the top of your wish list.