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.