I bought it to connect an SM7B to a DJ Mixer and it did its job perfectly. Of course, it also needs phantom power (which DJ mixers generally don't have, but that's another story).

Excellent boost of 27dB on my SM57, it eases the load on my audio interface which previously had to have full input gain to capture vocals with this particular microphone. I give it 4/5 because I would have liked to have at least a small adjustment in the preamp, e.g.: 13/27 toggle, so if you need something less, you can adjust it. Aside from this quirk of mine, it does everything it promises, so 5/5.

Note: it requires 48V phantom power to operate and does not pass phantom to the microphone.

An excellent tool that I prefer over others (e.g. cloudlifter), provides +27db of clean gain and even if your microphone doesn't need it, it's good to have it to lighten the load on the sound console and end up with a very clean sound. We are always talking about Voice as it is between 10Hz - 100kHz, for anyone who needs frequencies above 100kHz, then it necessarily goes to cloudlifter which is 20Hz - 200kHz. Good recordings to everyone!

Excellent especially for dynamic microphones that require a lot of dB gain. Clean sound without pushing the amplifier to its limits and consequently increasing noise. I bought it for the Shure SM7B, which is connected to the Golden Age 73 Deluxe and from there to the Focusrite 6 USB.