Cloud Microphones have a range of clean gain impedance matching inline boxes that offer better performance on low output dynamic or ribbon microphones, With the CLZ Mic Activator you also get to dial in the impedance, which can drastically change the tone of the input.
They've been getting rave reviews and now have introduced the new CLZi - which gives you a direct inject box for line levels too. Specifically for working with line level signals. You can also adjust the impedance for guitars etc which also can shape the tone of the sound before you even hit the destination preamp.
Here's a demo of the sound with a regular SM7B dynamic mic.